I-25 Northbound Mile Markers
0 New Mexico State Line, summit of Raton Pass
Descend abruptly into Colorado
1 Scenic overlook. Great lava flows cap ridges to east.
Exit 2 Wooten
3.4 Coal and dike exposed to east
5.5 marvelous channel sandstone with great margin on west side of road.
Exit 6 Gallinas
6.5 nice channel sandstone to east
7.0: roadcut to east has (poor) K/T boundary in upper level.
Exit at Exit 8 northbound. Drive a few 10's of meters. Stop at Crazy French Ranch Driveway. Get out of car and cross drainage to south on cement crossing. Duck under fence and gain high bench. In here there was a great outcrop of the boundary clay in 1995. It has largely slumped over. At the very beginning of the upper bench there is a possible boundary clay just a few centimeters below a thin coal. It is just below the slumped sandstone boulders and is not particularly satisfactory.
Exit 11 Starkville. Bob and Earle's family restaurant.
12 View to north of bluff in Vermejo sandstone with Trinidad label on it.
Exits 13 A, B Trinidad
Cross Purgatoire River
Exit 14 more Trinidad town
.
Exit 15 Kit Carson Trail and east to La Junta.
17 Bluffs of Trinidad Sandstone to west.
Exit 18 El Moro Road
20 Very good exposures of bluffs of white-capped Trinidad Sandstone to west. These are some of closest to road. Note very flat top of the Trinidad Sandstone and easy identification of the transition from Vermejo to Trinidad Formations. Vast realm of Pierre Shale out to east.
Exit 23 Hoehne Road
26 Views of Spanish Peaks to NW behind bluffs of sandstone.
Exit 27 Ludlow Massacre Memorial
29 Driving on Pierre Shale flats, dike forms a sauropod-like elongation out to ENE, Greenhorn Peak visible far to north.
Exit 30
Exit 34 Aguilar truck stop.
36 Good bluffs of Trinidad Sandstone close to the road to west.
37.8 Looks like a dike just to east of road, forms slightly resistant ridge in Pierre Shale.
39.1 Huerfano County Line. Views to west of Spanish Peaks
Exit 41 Rugby Road
Exit 42 Rouse Road and Pryor.
Exits 49, 50, 52 Walsenberg
Fill in here from other side….
Exit 201 Hampden Blvd (Rt 285).
Exit 204 Colorado Blvd. Denver is to your east.
Exit 214 Mousetrap, intersection with I 70.
Exit 216 I-76, Fort Morgan
Exit 217 Rt. 36 to Boulder
Exit 220 Thornton Parkway
Exit 221 Northglenn, 104 Ave.
Exit 223 120th Avenue.
224 Enter Wattenberg Field.
225.8 First wells visible to west; gas wells become common over next several miles.
Exit 229 Weld/Adams County Line (40 degrees north latitude, this is equivalent to Baseline road in Boulder).
Enter USGS Map I-855-G by Colton (1:100,000, 1978, Urban Corridor Geology.
230.3 Modest road-cuts in Laramie channel sandstone.
Exit 232 Erie.
233 Oil wells become common on both sides of road.
Exit 235 Rt 52, Dacono.
238.3 Ledge of Fox Hills Sandstone exposed on west, very nice o/c bulldozed in about 2003 to make a sound barrier so the alfalfa fields to the west can be better converted to residential sites. Many small spherical iron oxide concretions, no ophiomorpha.
Exit 240 Barbour Ponds
241.1 St. Vrain River; note sand and gravel pits in drainage basin; aggraded material is being quarried.
Exit 243 Rt. 66, North Longmont, Lyons, Estes Park.
Exit 245 Mead
249.9 very Little Thompson River
Exit 250 Berthoud
Exit 252 Johnstown, Rt. 60.
253.3 Weld/Larimer County Line.
Exit 254 Johnson's Corner Cafe.
Exit 255 Rt. 402 west.
255.5 Modest outcrop.
256.7 Big Thompson River.
Exit 257 A&B Rt. 34, Greeley and Loveland; take this route to Masonville. Entering map by Reade, 1978; you are in Pierre Shale.
258 Dog track to west.
Exit 259 Airport Rd.
Exit 262 Windsor, Fossil Creek Reservoir to west Good scaphites and inoceramids collected here.
Exit 265 Harmony Rd. Dinosaur (metal) on east.
265.9 Cache La Poudre River.
266.2 Rest area to east.
Exit 268 Prospect Road
Exit 269 A&B Ault and Fort Collins; still in Pierre Shale.
269B is exit for Laramie on Route 14.
271 Mt. Vista Drive.
272 Budweiser plant to west; Leave Colton, 1978 geologic map.
Exit 278 Wellington, still in Pierre Shale.
280.5 Deep oil wells
Exit 281 Owl Canyon
285.9 White Fox Hills Sandstone to east.
Exit 288 Buckeye road, Fox Hills Sandstone o/c at exit, note sharp top to this sandstone.
289.8 Laramie coal in roadcut to west.
292 Weld County Line. Between here and Carr Rd. you climb onto a tongue of the Tertiary overlap assemblage.
Exit 293 Carr Road; near 294 you drop back into Mesozoic. (Relationship better shown on State map than on Reade '78.)
295 Laramie sandstone outcrop.
295.8 Natural Fort. Rest stop in Laramie channel sandstones. In 1831 600 Crow indians killed 160 Blackfeet here. Best outcrops are south of parking lot. Ken Carpenter has a micro fauna site near here in Contributions to Geology (U Wyo.).
Kelly, T. M., 1990, Depositional environment and contorted bedding in the Laramie Formation, Cheyenne Basin, Colorado, unpublished Master's thesis, Colorado State University, 168 pp. Lower Laramie is comprised of crevasse splays, distributary channels, well and poorly drained swamps and interdistributary bays on a delta platform, Upper unit of meandering fluvial system on an alluvial plain. Laramie sediments were derived from west of the Front Range (p.20) Laramie sandstones are quartzarenites, w 5-10 % lithic frags (chert, claystone). Accessory include magnetitite, biotite, muscovite, rutile and amphibole. Paleocurrents flow to the SE mean of 130.5 degrees. Fluidization features are spectacular in these outcrops along the I -25 Natural Forts area. Deformation zones are in excess of 10 feet thick. Seismic shock a possibility as is dewatering due to compaction, or the disruption due to passage of diapiric mud.
297 Buffalo on hill comprised of White River overlain by Arikeree and perhaps by a skiff of Ogallala.
299 Wyoming state line; 8 miles to I-80 intersection.
Reade, H.L., 1978, Uranium deposits: northern Denver Julesberg Basin, Colorado, RMAG 1978 Symposium on Energy Resources of Denver Basin, p. 161-171. Includes terrific cross section.
I-25 Southbound Mile Markers
299: Wyoming Border
295.8 Natural Fort; Laramie Formation channel sandstone beds provided inadequate shelter to Blackfeet tribesmen in 1831.
Key reference:
Kelly, T.M., 1990, Depositional environment and contorted bedding in the Laramie Formation, Cheyenne Basin, Colorado, unpublished Master's thesis, Colorado State University, 168 pp.
The lower Laramie Formation is comprised of crevasse splays, distributary channels, well and poorly drained swamps and interdistributary bays on a delta platform. Upper unit of meandering fluvial system on an alluvial plain. Laramie sediments were derived from west of the Front Range (p.20) Laramie sands are quartzarenites, w 5-10 % lithic fragments (chert, claystone). Accessory include magnetitite, biotite, muscovite, rutile and amphibole. Paleocurrents flow to the SE mean of 130.5 degrees. Fluidization features are spectacular in these outcrops along the interstate.. Deformation zones are in excess of 10 feet thick. Seismic shock a possibility as is dewatering due to compaction, or to stratal disruption due to diapiric mud lump rise.
280.5: Deep oil wells.
265: Harmony Road; note the metal dinosaur to east.
Exit 262: Windsor.
258: Dog track to west
Exits 257A&B Rt 34 to Greeley and Loveland
Exit 254: Johnson's Corner eatery
253.3: Weld/Larimer Co. Line
237: Midst of Spindle oil field
Exit 235: Route 52, Longmont
230.2: Laramie channel sandstone outcrop in roadcuts.
Exit 214: Mousetrap; intersection with I-70. The city of Denver is built on a series of terraces above the South Platt River.
Exit 204: Colorado Blvd.
Exit Evans
Exit Yale
Exit 201: Hampden Blvd., Rt 285.
Exit 200 Route 225 to Aurora and DIA.
Exit 199: Belleview Road
Exit 198: Orchard Road
Exit 197: Arapahoe Road, go east to get to Centennial Airport.
Exit 196: Dry Creek Road
Exit 195: County Line Road: This is the Arapahoe - Douglas county line.
Exit 194: C-470
Exit 193: Lincoln Ave. Pediment surface on skyline to the SW. The horizon is defined by the top of the D2 sequence (locally termed the Dawson Arkose). Note gentle inclination into the Denver Basin and concordant surface in the crystalline Front Range.
The surface seen to the south formed on the top of the D2 sequence and is concordant with the "Eocene surface” on the Rampart Range.
Careful analysis by Leonard and Langford, 1994 indicates that there is no significant offset between these two surfaces. Thus the Golden Fault and its allies have not moved since the end of the Laramide orogeny. A key implication is that the mountains you see to the west are not Laramide mountains; they are the product of regional uplift and dissection of post 35 MY age. The Denver Basin along which you are driving was uplifted in concert with the adjacent ranges. The headward erosion of the Platte and Arkansas river systems created the Front Range escarpment which we recognize today as an obstacle to navigation.
Exit 192: Ridgegate Parkway
191.5: Olive mudstones west of highway are the very top of the D1 sequence. Note paleosol over top. These strata are equivalent to those containing the DMNS Paleocene rainforest found at Castle Rock. Bluffs are capped by resistant sandstones of the D2 sequence.
191: Channels in the D2 sequence to the west have been thought by some to be Castlerock conglomerate.
190.8: Paleosol on east side of road at road level. This regionally extensive paleosol was first recognized to be significant by Paul Soister of the USGS. It has subsequently been found to occur at the boundary between the D1 and D2 sequences.
Exit 190: Surry Ridge.
188.2: Modest road-cuts in mottled and finer-grained D2 sequence strata.
Exit 188: Castle Pines Parkway. Reuter Hess Reservoir is to the east, just out of sight.
Exit 187: Happy Canyon Road. Exit here for a view from the top of the overpass; Great view of Raspberry Butte, Dawson Butte, Pikes Peak and Devils Head. Note “Eocene surface” etched on Rampart Range.
186 Lovely view to the south of flat-topped mesas.
Views of the Castle Rock pinnacle coming up.
185 Wall Mt Ignimbrite (36.7 MY) caps butte to east of road. Plateau Quarry.
184.8 Paleosol is immediately to west in Parking lot for discount shopping arena.
Exit 184: Founder's and Meadows Parkways. Discount stores.
182.1 DMNS rainforest locality is immediately past RR overpass on east.
Exit 182: Wolfensberger Raod, Castle Rock town; Castle Rock to east is capped by the Castle Rock conglomerate containing meter sized angular clasts of the Wall Mountain ignimbrite. Conglomerate here rests with dramatic unconformity on the D2 sequence. North border of Map I-857-F, by Trimble and Machette (1979) at 1:100,000 scale.
Exit 181 Plum Creek Parkway.
180 Good views of decapitated mesa to east, the Centennial Quarry where Wall Mountain ignimbrite was made into building stones and gravel.
179 Old RR siding of Douglas used for quarry operations; rock went to Denver, Co Spgs and Pueblo. Entering Dawson Butte 1:24,000 scale quadrangle mapped by Matt Morgan and colleagues from the Colorado Geological Survey in 2003. This map is to be published in 2004.
NEW GEOLOGIC MAPPING
The area between Castle Rock and Colorado Springs has been the subject of a new 1:24,000 scale geologic map series produced by the Colorado Geological Survey. See references by Jon Thorson and his colleagues for the Dawson Butte, Monument, Greenland and Pike View quadrangles.
LOCAL STRATIGRAPHY
Castle Rock Conglomerate: Oligocene, fills a landscape scoured into the Wall Mountain welded tuff. Characterized by content of angular clasts of the underlying ignimbrite, contains Chadronian mammals including Titanotheres and rhinoceros (Morse et al. 1985)
Wall Mountain Ignimbrite: 36.7 MY. (Locally termed the Castle Rock Rhyolite) Erupted from near Mt Aetna in the Collegiate Range, flowed east across South Park and the Rampart Range. Predates the Arkansas valley. Preserved in Denver basin as the resistant caps of scattered mesas in the Black Forest area. Extensively quarried for building stone and aggregate. Here is clear evidence that by 36 MY the mountains of the Laramide orogeny had been beveled almost flat.
D1 sequence: Maastrichtian through Early Paleocene synorogenic package derived from the west. Characterized by abrupt facies transitions from coarse to fine in a proximal to distal sense. Composition ranges from arkosic to andesitic and back to arkosic.
D2 sequence: Eocene synorogenic arkosic strata derived from SW.
Dawson Arkose: Paleocene to Eocene. Overlies and is in part laterally equivalent to the Denver Fm. Coarse grained to west and to top, includes Green Mt Cgl. Contains a prominent paleosol recognized and discussed by Soister 1978.
Denver Fm.: Cretaceous to Paleocene. Both upper and lower boundaries are ill defined making mapping difficult. Characterized by andesitic clasts. Unit wedges out to the east and interfingers with the Dawson Arkose.
Arapahoe Fm.: a near mountain facies of the Dawson Arkose (Reichert, 1954, p. 54-55, Trimbel, oral communication 8/93). Some authors have mapped it as a separate unit where it is well developed such as in the type locality area west of Sedalia; however it generally fails the mappability criteria of a formation. In the Denver area, the granitic clasts imply uplift of the Rockies had proceeded to a point where granite was exposed.
Laramie Fm.: Contains sub-bituminous coals which accumulated landward of the Fox Hills beaches. Correlative to the Vermejo of the Raton and the Fruitland of the San Juan Basin. Often lumped with the Fox Hills for mapping.
Fox Hills Sandstone: Upper Cretaceous regressive sandstone; last regression of the Interior Seaway. Correlates with the Trinidad sandstone in the Raton Basin and the Pictured Cliff sandstone in the San Juan Basin. Base is conformable on the Pierre Shale; sandstone becomes younger to the northeast. Characterized by a salt and pepper texture, ophiomorpha burrows common; coarsens and shallows upward. Age is about 69 MY at Air Force Academy (Kluth and Nelson, 1988).
Pierre Shale: Marine shale, frequently bentonitic; fish scales and invertebrates common. Dated with ammonites. The shale was deposited on the floor of the Interior Seaway, correlative formations occur in states surrounding Colorado. Mapped in detail by Scott and Cobban, 1986, Map I-I627.
178 Abandoned subdivision to west with paleosol outcrops.
177: Dawson Butte to west peaking through grassy knolls. Topped by Castle Rock Rhyolite.
175: Raspberry Butte is the saddle-shaped butte ahead.
Exit 174: Tomah Road. South of KOA is a clay pit, possible paleosol.
Larkspur Butte is due south, Hunt Mt. to east is a paleovalley capped by Castle Rock cgl. Note scars on rim to east caused by 1965 Denver flood. There is a paleosol exposure in one of these gullies.
Exit 173: Larkspur.
Exit 172: Upper Lake Gulch Road. Raspberry Butte to the west.
171: Good views of Raspberry Butte to west. Beautiful massive white channels in the D2 sequence. At very top of butte is a wall of D2 sequence arkose capped by scree of Wall Mountain Ignimbrite.
170: Outcrops of white arkose on northbound lane, low in the D2 sequence.
169.8: Rattlesnake Butte due south is capped by Wall Mt Ignimbrite.
Note armored flanking wedges formed as butte washed away.
Exit 167: Greenland, ahead is Bald Mt.
Shelter belt trees on west, beyond to the west are some castle shaped bluffs of coarse white D1 sequence arkose. Behind to the west, note the excellent beveled “Eocene surface”.
166: D2 sequence again, resistant arkose graced with trees.
165: Lovely park-like landscape, a product of conservation easements obtained by Douglas County Open Space.
Exit 163: County Line Road. This is the El Paso/Douglas county line, note differences in land use!.
162.8: Crest of Monument Hill, 7352 ft. Two fake trees to west. Hill is held up by the relatively resistant coarse arkoses of D2. Ponderosa pine trees are starting to look bug infested in July 2010.
Descend onto the flats eroded out by the headward erosion of the Arkansas River system. Nice views of Cheyenne Mountain which has ridden up and to the east on the Ute Pass thrust fault..
162.4: D2 sequence again, coarse arkosic facies.
Exit 161: Woodmoor Drive; Monument, Palmer Lake; watch for pediments behind strip of fast food joints.
158.8: Keep sharp eye for a small paleosol o/c visible 1/2 mile to west.
Exit 158: Baptist Rd paleosol is near road level here.
Note prominent castle outcrop to the west, this is D1 on the north side of the Air Force Academy. A fine leaf locality is located to the west near railroad tracks.
Exit 156B: Air Force Academy entrance.
Exit 156A: Mining Museum to east, set up by Mr. Farr, DMNS fossil plant locality Scotty’s Palm to west.
155: To the west is the area where the progressive unconformities discussed by Kluth and Nelson (1988) are exposed on the southwest side of the Air Force Academy. Closer by note the channel outcrops to west in Upper D1 sequence(?).
Exit 153: Interquest Parkway, Black Forest.
152: Scenic area to watch gliders and parachuters at the AFA.
Exit 151: Briargate Parkway.
Exit 150: Academy Boulevard. Dropping into Arkansas River drainage; large limestone quarries in the Manitou Dolomite along the Front Range to the west.
Colorado Springs city limit
149.2: Deep gully crossing road is Woodmen creek a tributary to Fountain Creek. This gully has fine exposures of D1 in an alternating fluvial channel and overbank facies. Pyrite cemented concretions occur at shale interfaces.
Exit 149: Woodmen Road.
Exit 148: Nevada Avenue. Rockrimmon Boulevard. Cheyenne Mt ahead. The Ute Pass fault is the basin-bounding fault at this latitude. It has reportedly been penetrated beneath the impregnable fortress (Ron Calvert pers. com., 1989). Fault is noted to dip 25 degrees to the west placing Boulder Creek Gneiss over Fort Hays Limestone by Lewis, p. 257 in RMAG's 1978 guidebook.
147.5: Fountain Creek in Laramie Formation.
147: Pulpit rock to east.
Cross over RR tracks, small bluff on right is Laramie Formation, Fox Hills is not exposed, it is mapped to the east, on the other side of the McDonalds restaurant.
146.5: Outcrop of Laramie on roadcut to west. Fine-grained sandstone with coal beds. Fox Hills Sandstone is reported in creek bed to east, not visible from road. We are entering the Cretaceous biostratigrahic map prepared by Scott and Cobban, 1986. This exquisite map shows biostratigraphic control in the Cretaceous Pierre shale together with sketches of selected index fossils (Map I-1627).
Exit 146: Garden of the Gods; great visitor's center. University of Colorado Springs.
Last views of D1 in road cuts on west, note coarsening up from lignitic to gravels. Proceed down onto valley floor cut into Pierre Shale. No good outcrop of Fox Hills.
Exit 145: Fillmore Street.
Exit 144: Fontanero Street.
Exit 143: Uintah St, Colorado College, US Olympics Center.
Exit 142: Bijou Street, downtown Co Spgs.
Exit 141: Cimaron Street, Rt 24 W to Pikes Peak and Florissant. To west are tailings piles resulting from smelting of ore brought here from Cripple Creek.
Exit 140: Tejon Street, Rt 85 to Rt 115.
Exit 139: Colorado Springs International Airport. Paterson AFB, Rt 24 east to Limon.
Exit 138: Circle Drive, Cheyenne Mt Zoo and Broadmoor Hotel.
137: Good views of Cheyenne Mountain to the west.
Exit 135: Academy Blvd; traveling down-section, rounded hills are Pierre Shale.
Exit 132B: Fort Carson Gate 20.
Exit 132A: Mesa Ridge Parkway, Route 16 E. Wildfield, pediments form horizon to southeast, roadcuts in Pierre Shale.
130.5 Note water tanks on west
129.2 : Note concretions in roadcut on west, some are septarian.
Exit 128: Fountain town, piedmont covered by Verdos alluvium is to west.
Leaving USGS Map I-857-F of the urban corridor (1:100,000).
126.1: Note the 4-8 cm white streak in the road cut to the west (hard to see). This is a volcanic ash bed or bentonite. Also note ironstone concretions. Fossils are rare in these concretions but when found are uncrushed, indicating that the concretions formed early, prior to compaction.
125.9: You may leave the road here on a faint track to the west for a pull out stop. At the top of the small hill amidst a trash pile, the bentonite is exposed. John Obradovitch has dated this ash at 74.18 +- 0.09 MY.(see table 1 in Bull. Geol. Soc Am., v. 110, p. 361-376. Base of roadcut is in the Didymoceras stevensoni zone while the main part of the road cut is in the Exiteloceras jenneyi zone, about 1700 feet (1/3 of the way up) above the base of the Pierre Shale.
Exit 125: Nixon Road, cola fired power plant to west.
Exit 123: Canon City reentrant is visible off to the west.
Exit 122: Pikes Peak International Speedway.
120: The light gray roadcuts here are characteristic of the Baculites scotti zone of the Pierre Shale. To the north this zone merges with the Higgins and Hygeine sandstone members of the Pierre Shale.
119.5 Corvette center to west.
Exit 119: Rancho Colorado Boulevard, Midway.
118.2: Tepee butte in Pierre on right. Butte is held up by a very coarse nodular and fossiliferous limestone. Also note first appearance of Cholla cactus.
117.7: Roadcut on west preserves a cross section of a teepee butte. Fossils collected at this site include the soon-to-be formally named ammonite Hoploscaphities gilberti, Baculities scotti (named after Glenn Scott) and the abundant bivalve Lucina. We are about 1000 feet above the base of the Pierre. Immediately to the south more teepees occur. These features are about 15-20 feet wide and 50 feet in vertical extent and may have originated as methane seeps or vents on the sea floor.
117: Tepees on skyline to east.
116.5: Pueblo County Line, teepees visible on skyline to east. Watch for more teepees on west, close to road.
Exit 116: County Line Road.
Exit 114: Young Hollow. Ridge on the skyline to the ESE is the north end of Baculite Mesa.
111.4: Rest area on west. Pinon Rest Area.
Exit 110: Pinon, a major truck stop. Baculities perplexus crosses road just south of here - drive carefully (see map by Scott and Cobban) -we are about 600 feet above the base of the Pierre. Lovely view to the south of snow-capped Spanish Peaks and to the east is Baculite Mesa.
109.6: Cemented Pleistocene terrace material to west.
Exit 108: Pueblo West, Purcell Boulevard, Bragdon, we are in the Apache Creek Sandstone member of the Pierre Shale. This is age equivalent to the Menefee Formation of the San Juan Basin.
Exit 106: Porter Draw. Power plant visible to SSE.
Exit 104: Eden. To view Apache Creek Sandstone, exit here and drive 1 mile south on frontage road to an open borrow pit. Concretions and trace fossils are visible. We are about 400 feet above the base of the Pierre Shale. Baculities obtusus occurs in concretions at the top of the borrow pit. The Apache Creek Sandstone has a very sharp top, being overlain by the organic-rich and condensed lag-bearing Sharon Springs Member seen in diggings south of the Hampden Inn 0.5 miles to the south.
103.5 Pueblo city limits (4695’) Exits under construction, check numbers.
103: Baculite Mesa is the low dark ridge to the east, note sand and gravel operations on south end in the Nussbaum terrace alluvial cap.
Exit 102: Eagle Ridge Boulevard.
Exit 101 Route 50 W to Royal Gorge and Canon City.
Exit 100 B: Pueblo, Fountain Rim.
Exit 100 A: Route 50 E to La Junta and Bent’s Fort.
Exit 99: Downtown Pueblo, County buildings to west.
98.5: Top of hills on east are held up by the Smoky Hill Shale member of the Niobrara Formation.
Exit 98 B Bluffs of Qal along river.
Exit 98 A East to La Junta
97.6: Cross Arkansas River. The river bank and bluff south of the river is in a transition member between the Pierre shale and the Niobrara Formation.
Exit 97 B Abriendo Drive
Exit 97 A: Old CF&I steel mill to east, just barely operating. Coking coal from Raton Basin used here. I wonder where the iron ore came from? Colorado State Fair grounds.
Exit 96: Indiana Ave.
Exit 95 Illinois Ave. Vestas facility to east, dog track to west Huge Excel power plant to east..
94.5: Leaving Cretaceous biostratigraphic map by Scott and Cobban.
Exit 94: Pueblo Boulevard, large ridge of clinker and tailings to east along road.
92: A single wind turbine, forlorn and not turning, July 2010.
Exit 91: Stem Beach. Cement plant to east.
90-89: On the flats (generally supported by the Smoky Hill marls at the top of the Niobrara), nice views to southwest of Wet Mountains.
Ahead and to the east is a cuesta held up by the resistant Fort Hays Limestone.
Note cuesta is the west limb of a breached anticline. The Fort Hays is vegetated as is the Bridge Creek limestone member of the Greenhorn which appears in the core of the structure beneath the shale slopes formed by the Carlile Shale.
Exit 88: Burnt Mill Road.
In this area a well laminated white limestone outcrops to west in gully. This is the Fort Hays Ls. and contains Inoceramus deformis and Ostrea congesta (Weimer and Haun, 1960, p. 102). The Fort Hays is splendidly exposed on a south-facing scarp over the small gorge of the energetic St. Charles River at mile 87.42.
Exit 87: Verde Road; to east, Fort Hays Limestone rests unconformably on the Carlile shale; here the Juana Lopez is thin or absent.
85: Driving on Fort Hays Limestone.
83.4: Road-cut in Fort Hays.
Exit 83: No name.
82: Modest rest area in median strip. Ls. bluffs are Fort Hays, we are dropping down across the Carlile shale onto the resistant Bridge Creek limestone member of the Greenhorn.
79.5: Fossiliferous Graneros Shale to east.
78.1: To east, Graneros Shale outcrops near Hatchet Ranch gate.
Exit 77: Abby Road, Cedarwood, limestone bluffs marching out to the northeast. These bluffs are opposed by equivalent south facing bluffs of pale Niobrara (Fort Hays limestone) which cross road at mile 80.5.
76.5: Highway climbs, Bridge Creek Limestone forms roadside.
76: flaggy limestone.
Exit 74: Rye, Colorado City. Great stop to view upper Carlile. Exit here and cross over top of interstate, then go north on frontage road. Fort Hays holds up outcrop, look at underlying Codell sandstone. Juana Lopez is a bioturbated facies at the top of the Codell sandstone.
73: Limey units in creek bed visible as the road climbs the curved hill.
Exit 71: Graneros Road. Graneros Creek is the type locality for the Graneros Shale.
70: Roadcuts in marine sandstone to east, 2 degree Trinidad sheet shows this to be Dakota sandstone bounded by the Rock Creek normal fault downdropped to the north.
69.2: Pueblo County. line, entering Huerfano County.
log ties to page 103 of Weimer and Haun, 1960
At the county line, the Codell sandstone is about 100 feet below the surface and Upper Niobrara. Smoky Hill shales are at the surface. We are moving south down the flank of the Apishapa uplift into the Raton Basin. Ten miles to the west is the peak of Greenhorn Mountain at 12,347 feet on the southern end of the Wet Mountains. Greenhorn Mountain and the nearby limestones are named after the famous Comanche chief Cuerno Verde who was known as the "cruel scourge" and who was killed near here by the Spaniards in 1779. Note the pediment surfaces beveling the Cretaceous on the east flank of the mountain. Ahead to the SSE are twin Spanish Peaks.
71: To the east note the wooded Dakota Sandstone on the horizon. This is the crest of the Apishapa uplift.
Exit 67: Apache City; driving on the Smoky Hill marls at the very top of the Niobrara interval.
Exit 64: Lascar Road; Lascar is a RR siding 4 miles to the east. Just north of this exit is the contact between Niobrara Formation and the Pierre Shale. From here south to Trinidad the road is entirely on Pierre Shale; the underlying Niobrara Formation is exposed out to the east on the high plains.
64: Huerfano Butte visible about 4 miles ahead.
61: Mt. Mestas is the prominent mountain to the west in front of the Sangre de Cristo Range. It is an elliptical mass of microgranite with its long axis trending NW parallel to the trace of a thrust fault which carries Paleozoic strata over Cretaceous strata on the east flank of the range. This intrusive together with a series which occur to the south are thought to be Eocene (20-25MY) intrusions which intruded in the Eocene along the thrust faults. Just north and in front of Mt Maestas is Silver Mountain (10,522'), an Eocene-Oligocene stock with over 40 radial dikes extending from it in 360 degrees.
Exit 60: Huerfano. To the east, the Huerfano Butte (the orphan) is a plug of basalt at the intersection of two dikes. To the west, behind the southern tip of the Wet Mountains, is Huerfano Basin or Huerfano Park which contains the Eocene Huerfano formation, famous for fossil horses (Hyracotherium).
Northbound between exits 59 and 60 is a scenic area from which to admire Huerfano Butte, a small plaque graces the turn out.
Bridge over Huerfano River
Exit 59: Butte Road Access to Huerfano Butte, a nice hike.
Northern border of USGS Map OM 161 by Johnson and Stephens, 1955, 1:31,680.
Exit 56: Red Rocks Road: goes west to Calumet at the northern tip of the Raton Basin. Vermejo coals were extensively mined here, the Raton is truncated from above by the Poison Canyon Formation. This truncation relationship is clearly shown by the detailed mapping on Map OM 161 NW of Walsenburg.
Exit 55: Airport Road, unlikely tree farm west of road.
Exit 52: Walsenburg, Huerfano County Seat. It is worth driving through Walsenburg to see the dike crossing the road north of town. Ridge to south is this dike.
51 Great exposure of Pierre Shale.
Exit 50: Seventy one miles east to La Junta on Rt. 10. Suaropod trails in the Picketwire/Purgatoire River.
Cross the Cucharas River
Exit 49: South Walsenburg exit. Lathrop State Park and cutoff to San Luis Valley.
48: Bluffs of Trinidad Sandstone to southwest.
42 and 45. Well-exposed bluffs of Trinidad Sandstone to west. To the west above the bluffs is the intersection of Big Dyke and Small Dyke. The Trinidad Sandstone is equivalent to the Fox Hills Sandstone. It is best mapped in this area by two masters theses from CSM, one by Claudio Manzolillo.
43 Windy Acres ranch.
Exit 42: Pryor Road. Rouse and Pryor were two rival coal camps contiguous to one-another.
Santa Clara Creek; west of here the Trinidad sandstone is shown as two shingles on USGS Map OM 161.
Exit 41: Rugby Road. Southern boundary of USGS Map OM 161. Cross onto northern portion of USGS Map OM 174.
39.1 Dike crosses road.
38.9: County Line. Cross from Huerfano County into Las Animas County.
37: Abandoned brick ranch house. Trinidad is a famous source of brick.
35: Lynn Railroad siding. Bleached knobs of Trinidad sandstone to west; with a little pinnacle of same at mile 37.
Buried dinosaur sticking up to southeast.
Exit 34: Aguilar.
32: Good views to west of Spanish Peaks, and to the far east a long mafic dike holds up a distant ridge.
33 Cross small stream with dense gallery forest.
Exit 30: Aguilar Road. Strongly jointed sandstone forms rim of cuesta to west.
29.5: Landslide debris forms rubbly slopes to west at foot of Trinidad escarpment.
28: Abandoned ranches to west.
Exit 27 Ludlow, point of interest, United Mine Workers of America Memorial of the Ludlow Massacre. Fred Meissner's wife Jackie's mother was born in Rouse and was present at the UMW battle at Ludlow. Her mother pushed her to the ground as hot lead perforated the canvas around them and they survived.
26 Coal mines in Vermejo Formation visible up valley to west.
24 Massive sandstone midway up bluffs to west is a classic exposure of the Trinidad Sandstone; beneath it the Pierre Shale and above it the Vermejo Formation equivalent to the Laramie Formation.
Exit 23: Hoehne Road. Possible teepee butte to east.
20: Skyline on SE is a lava flow.
16-21: Views to west of the Trinidad Sandstone. Note the gradual transition down into the Mancos Shale and the generally abrupt flat top, often bleached white. Keep an eye out for clinoforming to the north, regional studies show shingles occur here.
Exit 18: El Moro road. Good exposure of base of Trinidad Sandstone to west.
15: Note barn made of brick to west.
Exit 15: Kit Carson Trail, Trinidad city limit (6025’).
14: Note Trinidad sign on bluff to west. This sign is placed on a massive fluvial sandstone bed in the Vermejo Fm. that sits directly on the Trinidad Sandstone.
Exit 14: Downtown Trinidad.
Exit 13 A,B: Main Street of Trinidad, cross Purgatoire River.
Holiday Inn is south of town.
Leave Map OM-174.
Exit 11: Starkville, Holiday Inn.
11 Overpass
In the area between here and Raton Pass are many excellent outcrops of the K/T boundary. This is where the K/T boundary was first recognized in non-marine rocks. Chuck Pillmore of the USGS was the main worker in this area. Farley Flemming did his PhD thesis on the pollen of this area. See the following excellent web-reference to get specific locality information:
http://climchange.cr.usgs.gov/info/kt/
10.5 Dike and small fault in pale ss in roadcut to east
9.5 Fluvial sandstone channel to east
9 Nice outcrop of sandstone to east, valley to west with railroad.
8.5 Convoluted white sandstone to east
The best o/c of K/T is in next roadcut to north at Exit 8 northbound. The north end of this roadcut upper level has a very fine boundary clay visible at 60 mph when south bound on I-25.
Exit 8: Spring Creek access to K/T boundary on upper level.
odd mafic volcanic conglomerate to east.
At exactly Mile 7: roadcut to east has (poor) K/T in upper level.
6.5 Nice channel sandstone to east
Exit 6 Gallinas
5.5. Marvelous channel sand with great margin on east side of road.
4 Open valley, climbs gently top south.
3.4 Coal and pair of dykes exposed to east
Exit 2 Wooton
2 Climbing to Raton Pass
1.5: Sign for crossing bears.
1.2 Coals and channels on west side of road
Exit 460 Raton Pass Summit, Laval flows to east.
ENTER NEW MEXICO
I-70 Westbound Mile Markers
Edited by Bob 11 September, 2022
The mileposts count down the distance to the Utah border and the exits are named for the nearest milepost.
Leaving Denver, you head west past South Table Mountain and Green Mountain.
Mile 258 Road cut through the Dakota Hogback. This famous locality exposes the Dakota and Morrison formations in great splendor. LeRoy and Weimer (1971) published a one sheet description of the strata as exposed on both sides of the highway. To the south the hogback is known as Dinosaur Ridge, named after the bones exposed in the Morrison Formation and the trackways on the top of the Dakota Sandstone that holds up the resistant ridge. Note the wind gap, a former course of Mt Vernon Creek. An easily accessible trail along the hogback reveals granite pebbles and cobbles in this notch.
Here we pass from the plains into the mountains.
Exit 259 Morrison town is located a few miles to the south, the namesake for the Morrison Formation.
Cherry Gulch landslide is visible to the south as a high bench armored by slabs of Fountain fm from a collapsed flat-iron. Large park and ride lots are present at this exit. TRex is to NE, Wooly Mammoth to NW. Field trips often gather here. As you climb the hill, exposures of Precambrian metamorphic rock collectively termed the Idaho Springs Formation are visible to the north. These develop into excellent roadcuts showing various gneissic and schistose textures cut by pegmatite dikes.
Exit 256 Buffalo Bill’s Grave: He died while visiting his sister in Denver in 1917 and there was considerable competition for his body. The site north of the road advertises itself as the “One and only grave of Buffalo Bill”.
Exit 254 Genesee Park
Mile 254 Picture Frame Bridge, designed to frame the view to the west.
Exit 253: Chief Hosa: Great views to the west of the Indian Peaks Range, keep an eye out for buffalo herd.
Exit 248: Beaver Brook and Floyd Hill
Mile 246.5 Top of Floyd Hill, a fierce challenge to early stage coaches.
Mile 245 Quarries to the north, Idaho Spring fm is crushed and sold.
Exit 244 Rt. 6 and Golden. Rt. 6 follows Clear Creek drainage.
Exit 243 Hidden Valley Central City Parkway; on the crest of the hill to the NW there is a splendid deposit of very coarse gravels and boulders. Some think this is a moraine, others that it is a proximal feeder channel to the Ogallala.
Mile 242.2 Tunnel; great pegmatites on east end. Tunnel was widened in 2016. As you emerge from the tunnel the wooden bridge to the south is dedicated to a high school student who was eaten by a mountain lion near here in the 1980’s.
Exits 241 A,
B & 240 Idaho Springs. Note water wheel on south and Argo Mill tailings on the north. The Argo tunnel connects this area with the Black Hawk / Central City area and served to drain water and carry ore from these mining districts to the north. To the south is the Indian Hot Springs spa; features banana trees in a large glass enclosed pool and subterranean hot vapor rooms.
Mile 239 Roadcuts in sulfide-stained rocks. Mining activity on all sides.
Exit 238 St Mary’s Alice (really St Mary’s Glacier). There is a small ice patch a few miles to the north that is a glacial remnant.
Exit 233 Lawson
Exit 234 Dumont and Downieville; Famous 5 cent coffee at the Sinclair station.
Watch for patches of moraine plastered on valley walls to the north. Characterized by extremely poor sorting. These are the lowest remnants of glaciation in the valley; the Pleistocene valley glaciers did not extend below Idaho Springs.
Exit 232 Empire, Beyond Empire on road to Jones Pass, is the underground Henderson molybdenum mine (Wallace et al., 1978) producing 10-30 million pounds of moly/year. In Empire, the Peck House offers ghosts and Sunday brunch, Route 40 heads up over Berthoud Pass to the Winter Park ski area and Middle Park. The ridge dividing the Empire valley from the Georgetown valley was overtopped by ice as this U shaped valley was carved.
Exit 228 Georgetown elev 8519, Hotel de Paris served fresh oysters about 100 yrs ago. Note levees along the dry fans to the north; these were built during a rare rainstorm in about 1990 when debris flowed across the road, closing the interstate. Watch for mountain sheep and for rocks plummeting from above. Behind Georgetown is a beautiful example of a hanging valley. There is a pumped water energy storage project here.
Mile 227 Note adits exposed in road cut, also small waterfall.
Exit 226 Silver Plume, elev 9118, home of the Plume Saloon and the Pelican mine. Sulphide samples may be collected on tailings piles, chalcopyrite, bornite, and pyrite common.
Mile 225 Granite for the State Capitol was quarried from an unimpressive area behind tin building. This is the Silverplume granite.
Exit 221 Bakerville exit, access to Grays and Torrey peaks (14’ers) to the south.
Exit 216 Loveland Pass and ski area.
Mile 217.4 At large electric sign is a monument to a sports team, died in an air crash.
Mile 216.5 Seven Sisters avalanche chutes to the south. One falls into the Loveland parking lot.
East End of Tunnel: Eisenhower Tunnel elev. 11,013' (east) 11,158' (west). The steep descent towards Dillon features a variety of avalanche chutes and slump features which the highway department struggles with. These are Precambrian metamorphic and intrusive rocks.. As you approach the valley floor watch for the transition back into sediments. The relationship is not clear in the road cuts, but elsewhere it is demonstrated that the Precambrian is thrust to the west over Mesozoic strata. This is the Williams Fork thrust fault.
Mile 213 West end of tunnels, start descent down slumping face of shattered crystalline rock.
Mile 212 Landslide, east-bound lanes falling off the mountain.
Mile 207-206 Silicified Dakota sandstone, with overlying Mancos shale to the north. Note small thrust in road-cut mimics the Williams Range / Elkhorn Thrust that carries granite westwards over Cretaceous. This thrust was encountered by the Roberts Tunnel which connects Dillon Reservoir to the South Platte drainage near Grant on Rt. 285 (Robinson et al., 1974).
Exit 205 Silverthorne and Dillon. Road to Kremmling along the Blue River.
Mile 203.5 View of Dillon Reservoir; this lake provides approximately 50% of Denver’s water.
Exit 203 Frisco east, food and gas.
Exit 201 Frisco west, enter the narrow canyon between the Ten Mile and Gore ranges. Note glacial polish on valley walls to north, note fault to south, note mine to north with crystalline siderite. Splendid views to SE of the jagged Ten Mile Range.
Exit 198 Officer’s Gulch, many glacial features near here, tilite, roches moutonnees.
Mile 196.4 The Mosquito normal fault is well exposed as a polished face on the northwest side of the Ten Mile Range. This is best admired when driving to the east. Fault dips about 60 degrees to the west.
Exit 195 Copper Mountain, road to Fremont Pass, Leadville and Buena Vista.
Copper Mountain ski area to south; watch here for the Gore Fault, it slices across the interstate imperceptibly between mileposts 194 and 193 where scree and float change from granite to red beds. There are many thousands of feet of downthrow to the west. You are entering the Pennsylvanian/Permian Eagle Basin.
Mile 193.6 Outcrop of basement, Gore Fault near here.
Mile 192 Outcrop of redbeds, flat lying redbeds, relatively fine grained, cross bedded, fluvial w/ overbank deposits.
Mile 191 Same flat lying redbeds, pebbly sand outcrop to north.
Exit 190 Vail Pass, rest stop, road to Shrine Pass and Red Cliff.
Pass truck pull off point and then plunge down into the Vail valley; pay attention to o/c along road. Here we flirt with the Gore fault which is just to the north sub-paralleling the Interstate.
Mile 189.2 Vail Pass Summit (10,603’ eastbound & 10,662’ westbound).
Mile 189 Good road-cuts in flat lying red beds with pebbles and overbank deposits. Note the bedforms indicate these are fluvial (water-lain) rather than true alluvial fan deposits.
Note across river to south the bedded nature of the Minturn/Maroon formations.
Mile 185.5 Truck escape ramp with excellent outcrops of flat lying red beds.
Mile 185: Cross Vail Creek
Mile 184 Outcrops to south of flat lying Minturn/Maroon; pebbly fluvial facies.
Mile 183 Approaching second runaway truck ramp; now look up the valleys to the north for the Gore Fault. Gore Creek drainage coming in from east. At base of hill look up the valley to the north (right) across the truck ramp, past Vail town limit sign. At the head of the valley you can see the crystalline basement forming the footwall of the Gore Fault.
Mile 182 Big bend as the road goes over Gore Creek. There are basement outcrops on the south side of the road.
Mile 181 Gore Fault crosses the road.
Exit 180 East Vail; Outcrops of Minturn/Maroon form bluffs projecting through the vegetation of the housing developments to the north.
Mile 179 At milepost, look north again and you see the crystalline basement behind the Gore fault with in the foreground on the downthrown side of the fault. This is Booth Creek and one may hike to the fault trace in about an hour. It is spectacular.
Mile 178 Golf courses to the south, landslide debris to north in large unstable road-cuts.
Exit 176 Vail exit with microwave repeater station and main Vail parking structure on south. Pedestrian overpass.
Exit 173 West Vail access
Mile 173 Enter a narrow canyon in Minturn/Maroon formations.
These well bedded fluvial (?) deposits can be looked at in detail at a couple of spots on the north side of westbound lanes. There is carbonized oil (graphite) in some of the strata at road level. Some remarkable slumping in deltaic facies.
Mile 172 Main body of road-cut, near here John Karachewski reported finding a cycad stump in situ. Cross Eagle River.
Exit 171 Minturn and Battle Mountain. Here is where John Karachewski did his work on the Minturn fm. To the south can be seen the Lion's Head, an algal reef in the clastic- dominated Minturn/Maroon fm. See Paleozoic references in Eagle Basin files; especially work by Walker. Glacial gravels plastered against the wall of Minturn / Maroon strata to the north.Landslide on south where the entire area is slumping to north against the river. Strongly deformed beds can be seen on the frontage road (Rt 6). See Tweto and Lovering, 1977 for a description of the Minturn area.
Exit 169 Eagle Vail
Exit 167 Avon, Walking Mountain Science Center is to the north behind the fire station.
Across to south is the Beaver Creek Ski area, note west-facing gypsum cliff at the entrance to this valley. This appears to be a diapiric structure. Bald evaporite beds support little vegetation on south facing slopes; Single Tree development to the north- appropriately named! Gypsum o/c to north behind condos. Found a fossil cycad here 11/95.
Mile 165 Note gypsum outcrops to the south in bluffs over Eagle River.
Exit 163 Edwards: Arrowhead ski area access.
Mile 162 Views to the south of the north side of the Sawatch Range.
Mile 160.2 Very sharp turn off to rest area at Wilmore Lake. Mud flat and shallow marine facies.
Mile 160 Abrupt dip change as you enter a tight fold that is well exposed north and west of Wilmore Lake. Near vertical beds whip out of the Mintun / Maroon strata giving a rapid climb up section through the orange colored State Bridge and Chinle formations capped by the eolian Jurassic Entrada Sandstone.The Entrada is overlain by the Morrison, then the Dakota sandstone. These are overlain by the dark Cretaceous marine shales. Cross Eagle River: Look immediately north: Excellent Dakota on Morrison exposures; now enter a Cretaceous dark shale valley at mile 158; gray beds to north are the Niobrara carbonate-rich units.
Exit 157 Wolcott; Route north to State Bridge.
Mile 157 Excellent o/c of Cretaceous shales over the resistant Dakota ledge just above the river.Laminated sands visible in Mancos shales here. At curve in Interstate note the Dakota on the south outcrops very well. Contact with Morrison is at road level to the south. On the north is a prominent ledge of Dakota at mid skyline. As we descend the valley, the Entrada Sandstone forms a bleached band over the Minturn; note eolian cross beds at mile 154.
Mile 156 House and stables built on Dakota outcrop to the north.
Mile154 Cross Eagle River, wonderful outcrops of State Bridge Fm at road level. These are overlain by the Gartra Conglomerate bed (resistant ledge mid way up the cliff; contains sub angular quartz clasts to 5 cm) this bed defines the base of the orange Chinle Fm; At the top of the hill is the salmon colored eolian Entrada Sandstone (Entrada equivalent).
Mile 153 Pale sandstone unit to the south is the School House member of the Maroon Formation. This tongue pinches out here and thickens to the west where it defines the top of the Maroon Formation. Further to the west it thickens and becomes the Weber Sandstone (famous reservoir rock in the Rangely oil field). The white color may be an oil stain signaling a breached stratigraphic trap sealed by the State Bridge. Immediately east of the pinch-out the top brown sandstones of the Maroon Fm were quarried in the Sherwood Quarry to produce the building stones for the Brown Palace Hotel in Denver in 1892. East of this area where the School House marker bed is absent, it is difficult to pick the transition from the Maroon to the State Bridge formations.As we descend in the section to the west, the redness diminishes and we are now in the lower gray facies of the Eagle basin; transitional into the Eagle Basin Evaporites and the Belden Shale.
Mile 151 The gypsiferous evaporite facies of the Eagle Valley Formation and the Eagle Valley evaporites. Dips are very variable due to diapirism of gypsum and the development of river anticlines in this reach of the valley. The river anticline structure (common along Colorado River south of Moab) is best seen when driving eastwards in this area.
Mile 150 Mantled gypsum beds to north
Mile 149 River gravels mantle slopes to north: these are Eagle River terraces.
Mile 148 Rest Area
Exit 147 Eagle, elev. 6600; go north to see an outcrop of gypsum behind the bank. Eagle County Regional Airport and Hardscrabble Mountain to the south.
Mile 146.5 Great o/c of gypsum to north very crenulate; large excavation on valley floor to south
Mile 145 Gypsum outcrops to south as bald pinnacles
Mile 144 Gypsum beds to north
Mile 143 Evaporites in the roadcut to the north.
Mile 142 Large outcrops of evaporites to the north. Open pit mine just out of sight.
Mile 141 Spires of gypsum to the north.
Exit 140 Gypsum; Eagle Gypsum plant that makes wall board from the Eagle Basin evaporites. Gypsum quarry is located out of sight north of the road.
Mile 139 Dark gypsum to the north, note reddening as we climb in the section.
Mile 138 Still gypsum to north. Drive through a diapir. Note red cliffs to north; endeavor to get the sense of the basin filling -first with evaporites, then with non-marine molasse facies.
Mile 137 Gypsum in the valley floor. Note Minturn on the valley wall. At Dotsero sign a rubbly Aa lava flow crossed the Interstate.
Mile 134.5 Be alert for Aa.
Mile135 The 4150 year old volcano is located above and beyond trailer parks to north; note the cinder block factories. The Aa flows south of the road are being flattened out (April 2000) and will probably be built upon.
Exit 133 Dotsero: The Colorado River arrives from the north and is joined by the Eagle River.
Mile 131 Note Belden black shales. Enter Glenwood Canyon: Mississippian carbonates with karst surface.Garfield Co. Line: well-bedded Paleozoic carbonates; note faults in these strata near mile 130.
Exit 129 Bair Ranch; Mississippian karst surface to south opposite White River sign.
Redescend the section into laminated Paleozoic shelf sediments.
Exit 121 Grizzly Creek exit.
Mile 127.5 First tunnel
Mile 127 Laminated Paleozoic dolomite
Mile 126 granite contact with overlying Sawatch; fly over river into tunnel
Emerge from tunnel in Precambrian pegmatites in granite, good views of basal unconformity across the river to the south.
124.5 Nice pegmatite dikes; panoramic view to the west of the “Great Unconformity”.
Exit 125 Hanging Lake (a treasure being loved to death) and Shoshone Dam.
Mile 124.5 Nice pegmatite dikes, panoramic view to the west of the “Great Unconformity”
Exit 123 Shoshone
Mile 122 Hydroelectric power plant. Two pipes carry 1250 cubic feet per second of Colorado River water (deflected from the river near mile post 125) down a 165 foot drop. This generates 15 mw of electricity. This is a simple ‘run of the river’ power plant. The turbines were installed in 1906 and are owned by Xcel. The water use is based on a 1902 water right. This is the senior water right in this region; it requires that all upstream users allow at least this much instream flow. By maintaining flows of at least this amount, fish habitats are preserved and natural saline springs are diluted ensuring water quality for downstream irrigators. Along the 2-3 mile stretch of river above the power plant very low, to no-flow conditions may occur in the summer. Below the plant, rafters revel.
Exit 121 Grizzly Creek; climb back into sediments: thin bedded Paleozoic strata
note caves and dissolution. You may return to Hanging Lake from here.
Mile 120.5 Cross fault, down dropped to south, emerge near the top of the basement.
Exit 119 No Name: Good roadside rest stop with excellent views of tower karst surface on top of the Leadville Limestone. At the exit and to the west are outcrops of the Molas Formation (red beds on the karst surface).
118 Enter tunnel; Excellent karst to east of tunnel, emerge in Precambrian to west of tunnel.
Mile 117 Emerge from Glenwood Canyon. Vapor caves occur on top of the Leadville to the north; free bathing pools are in the river at low flow stages to the south.
Exit 116 Glenwood Springs. Springs emanate from the karst surface, flowing at a rate of 2500 gallons per minute of 123 degrees F water. Road log ties for next few miles with pages 35-36 of Grand Junction Geol. Soc.Guidebook 1982. Limestone from quarries north in Leadville Ls was used for sugar processing in Delta.
Mile 115 Red beds of Minturn Maroon strata to south, karstified surface to north, look for outcrops of dark Belden shales to north. Cable car to Glenwood Caverns Adventure Park on north.
Exit 114 West Glenwood Springs, To the north is a good set of outcrops of the Mississippian surface with overlying gypsum, Belden, and Minturn Maroon formations.
Mile 113 Top of ridge was burned in the Storm King fire which killed 14 firefighters in summer 1994. At 11:00 is an exposure of light colored School House member of the Maroon (Weber sandstone) separating the overlying State Bridge Fm from the Maroon Formation.
Mile 111.2 View to south up South Canyon. The strata are color coded: the red upper Maroon is overlain by the white School House member, overlain by the orange/red State Bridge and orange Chinle formations; in turn overlain by the bleached Entrada Sandstone and the variegated Morrison Formation. A thin gray fossiliferous dolomitic limestone, the South Canyon Creek Member is present in the lower part of the State Bridge Formation.
Exit 111 South Canyon. Excellent exposures of the Permian through Upper Cretaceous strata. Access is very good. Cross over the iron bridge and head a little ways south. Flooding in about 2015 washed outcrops east of the road clean.
Mile 110.4 Mudslide washed people into the river fall of 1994; note rapids from debris.
Exit 109 Canyon Creek. Minturn/Maroon redbeds. Note the Grand Hogback ahead; the redbeds are o/l by the Weber, State Bridge, Chinle, Entrada, and Morrison formations. Morrison to south in good exposures, near mile 108 a Morrison quarry yielded dinosaurs, also uranium mined from Morrison.Dakota and marine Cretaceous to north on railroad cut.
Mile 107.5 Morrison Fm exposed on bluff across river to the south..
Mile 107-106 To the south is Coal Ridge. Sandstones, shales and coals of the Cretaceous Mesaverde Group are exposed on the north-facing flank. Red bands mark burned clinker horizons; the lower band is the Wheeler coal bed and the higher burned coal is the Allen coal bed. On occasion, steam rises from coal still burning within Coal Ridge. In the winter, the snow is often melted from the areas above the active bur
Exit 105 New Castle; Section here is Cretaceous through Mesaverde in the Grand Hogback.
Mile 104 Burned coal to south, gypsum to north.Balloon willows in development across river to south.
Mile 102 To the west is Battlement Mesa capped by Miocene basalt flows. Tertiary section visible to the WNW. Pediments to the north dip gently into the axis of the drainage.
Mile 101 East end of Battlement Mesa visible to the south.
Mile 99 Welcome to the Piceance Basin!
Exit 97 Silt, elev 5432’ nice pediment surfaces coming down from the south.
Cross Colorado River.
Exit 94 Rifle Garfield County Airport. Battlement Mesa ahead: Roan Plateau site of abandoned oil shale projects failed abruptly in 1982 when Exxon accountants pulled the plug.
Mile 93 Oak Canyon anticline visible to north; Drilled unsuccessfully by Mobil.
Exit 90 Rifle elev. 5345’ Route 13 goes north to Meeker and Craig.
Mile 88.5 Cross Colorado River.
Mile 88 Major sand and gravel operations to the north.
Exit 87 Second chance to catch Rt 13 north to Meeker and Craig.
Note many gas wells for the next few miles. These are tight gas wells in the Mesaverde of the Piceance Basin. Gas production is from sandstones at depths of 5000-7000 feet. Fields are the Rulison, Parachute and Grand Valley.
Mile 86 Roan Plateau to the north.
Mile 82 Excellent channels in Wasatch to north.
Exit 81 Rulison. Variegated beds of the Wasatch to the north; note channels and trough cross beds. Well developed terraces to the south. Several miles south of here the government tested a 40 kiloton nuclear bomb underground in an attempt to fracture a tight gas reservoir. Reports were that the little bit of gas obtained was contaminated with radioactivity and such efforts were put on hold.
Mile 78 More gas wells to the north.Note color change to north on cliff, variegated at base, drab to top--this represents a deepening up into lacustrine transition environments: the transition from the Wasatch up into the Green River strata.
Exit 75 Parachute elev.5095’ (pop. 250) Battlement Mesa (pop. 2134). To south on terraces are the retirement communities built in the Exxon company town that was abandoned May 2, 1982 (known locally as Black Friday) after Exxon decided not to develop the oil shales. Unocal built a 10,000 barrel per day retort plant north of the road here in 1983. During 8 years of operation this plant yielded 4.5 million barrels of 34 API oil. This is the largest shale-oil effort in US history but was abandoned in 1991 because it was uneconomic. The main interval being mined and retorted is the Long Ridge zone. This zone contains 34 gallons of recoverable oil per ton of shale. It is estimated that the retortable oil in this zone is 1.6 billion barrels. Local Coal stratigraphy: See: 1991 RMAG Coal bed methane of North America vol. (black one); Note figure 5 on p. 6 for strata south of the road, and fig 6 p. 215 for an E-W section going from Parachute to the east.
Exit 72 West Parachute, Wasatch channels to north.
Mile 71 Note transition from fluvial Wasatch to lacustrine Green River in slopes to the north. Fluvial facies is comprised of isolated shoe string sands and abundant paleosols
Mile 68 Pediments from the south form a clean mid-distance skyline
Mile 66.5 Garfield/Mesa Co. Line, road descending into Cretaceous.
Mile 64 Note lateral amalgamation of the fluvial systems.
Mile 63 Cross Colorado River
Exit 62 De Beque; Old sandstone school house to the north with one remaining outhouse.
Mile 60 Powderhorn ski area visible to the south on Grand Mesa.
Mile 58.5 Cross Colorado River (in flood 5/11; beaver road kill on eastbound lane).
Mile 58 Sandstones to the south are remarkably flat layered -could be a marine tongue in here?
Cross River twice more
Mile 57 Top of cliffs to the south are flat topped and a white cap occurs at road level; these are transgressive surfaces of erosion.
Mile 55 Note channels in fluvial strata.
Mile 53 Ponder the volume of sand in this system! Resembles the Blackhawk near Price.
Mile 50.5 Tunnel (double tunnel entrance in sandstone).
Mile 51.5 Active landslide on the south.
Exit 49 Route 65 to Colburn and over Grand Mesa to the south. Roller dam across river. Plateau Creek. Grand canal has its source near here.
Exit 47 Island Acres State Rec. Area; Coal mines on the north, these are the coals following the shorelines of the progradational Bookcliffs. Good river pebbles and birdwatching here.
Exit 46 Cameo coal mine was located up the valley to the north. The mine mouth Cameo coal fired power plant was located immediately across the river to the north. In 2009 an innovative program Excel installed a parabolic solar grid to preheat the power plant water at a cost of $4.5 million. About 2012 the plant was decommissioned as un-economic by Xcel and the entire facility razed. Today there is a shooting complex on the grounds.
Exit 44 West Palisade, Note springs pouring forth from abandoned coal mines to southeast.
Mile 43 Cross river, pop out into the Grand Valley with thick marine shales at base of Bookcliffs. Note strata dip to the north about 15 degrees. Rollins Sandstone form the very top of Mt GArfield; below, the Cozette Sandstone forms a major cliff. Vineyards to south, more every year. Large slump blocks occur on the slopes of Mt Garfield.
Exit 42 Palisade, Uncompahgre uplift forms skyline to the south west, note slumps to the north.
Mile 40.5 Look for hoodoos to the north.
Exit 37 Clifton and Grand Junction. Unaweep Canyon entrance visible to the south.
Mile 34 Cozette Sandstone forms a cliff top to the north. Note color banding in the underlying shales. The dark shales are marine; the gray to yellowish represents a coarsening upwards succession.
Exit 31 Grand Junction, Horizon Drive; Airport exit.
Exit 28 24 mile road. Colorado National Monument to the south. Best data including a very nice stratigraphic column and a road log through the Park (see Lohman, 1960).
Exit 26 Rts 6 & 50 and 22 Mile road.
Exit 24 Redlands Parkway.
Exit 19 Fruita, elev 4498’ Home of Mike the headless chicken and a fine Dinosaur Museum.
Mile 17 Cross Colorado River
Exit 15 Loma, Road north to Rangely and the Douglas Creek Arch.
Exit 11 Mack
Mile 10-9 Coals and black organic shales in Dakota. The transgressive surface of the Mancos overlies this non-marine strata.
Miles 7-5 Road follows the basal Dakota sandstone dip slope. Note outcrops of Morrison to south, Mancos to north. The basal Dakota is called the Cedar Mt/ Buckhorn Cgl. (This is equivalent to Lytle.) Basal shales of Mancos are distal Tununk. Note cross bedding in massive fluvial channels in the Morrison.
Mile 4-3 Massive fluvial facies of Morrison, note cross beds and the difficulty of differentiating Morrison from Dakota sandstone beds.
Exit 2 Rabbit Valley Trail through time. This area is well illustrated in an article in the Dinosaur Triangle book. In-situ dinosaur fossils in the Morrison Formation easily accessible on a gentle trail. A special treat is a most excellent Camarasaurus skeleton only 5 minute walk up the hill.
Mile 1 Morrison and Dakota sands. A fire burned grass and pinyon pines in this area in about 2005.
Mile 0 STATE LINE 3.5 miles ahead is a rest area with basal Dakota chert pebbles.
References:
Bass, N.W., and Northrop S.A, 1963, Geology of Glenwood Springs Quadrangle and vicinity. northwestern Colorado, US Geological Survey Bulletin 1142-J.
Kellogg, K.S., Shroba, R.R., Premo, W.R., and Bryant, B., 2011, Geologic map of the eastern half of the Vail 30’ by 60’ degree quadrangle, Eagle, Summit, and Grand counties, Colorado; US Geological Survey Sci. Inv. Map 3170, 49 pp pamphlet, scale 1:00,000.
Kellogg, K.S., Shroba, R.R., Bryant, B., and Premo, W.R., 2008, Geologic map of the Denver West 30’ x 60’ quadrangle, north-central Colorado; US Geological Survey Scientific Investigations Map 3000, 48 p pamphlet, scale 1:100,000.
Kirkham, R.M. and Scott, R.B., 2002, Introduction to Late Cenozoic evaporite tectonism and volcanism in west-central Colorado; in: Kirkham, R.M., et al., eds. Late Cenozoic evaporite tectonism and volcanism in west-central Colorado; Geological Society of America Special Paper 366, p. 1-14.
LeRoy, L.W., and Weimer, R.J., 1971, Geology of the Interstate 70 roadcut, Jefferson County, Colorado. Colorado School of Mines, Professional Contribution 7, 1 sheet.
Lohman, S.W.,1960, Colorado National Monument and adjacent areas, in: Guide to the Geology of Colorado, Weimer and Haun eds., p. 86-91.
Lohman, S.W., 1963, Geologic map of the Grand Junction area, Colorado USGS Map I-404.
Robinson, C.S., Warner, L.A., and Wahlstrom, E.E., 1974, General geology of the Harold D. Roberts tunnel, Colorado; US Geological Survey Professional Paper 831-B, 48pp.
Tweto, O., and Lovering, T.S., 1977, Geology of the Minturn 15 minute quadrangle, Eagle and Summit counties, Colorado; US Geological Survey 956, 96 pp.
Wallace, S.R., MacKenzie, W.B., Bair, R.G., and Muncaster, N.K., 1978, Geology of the Urad and Henderson molybdenite deposits, Clear Creek County, Colorado; Economic Geology, v. 73, p. 325-368.
Williams, Paul L., 1964, Geology, structure, and Uranium deposits of the Moab quadrangle, Colorado and Utah, USGS Map I-360, 1:250,000.
I-70 Eastbound Mile Markers
Mile posts count up away from the border and exits are numbered after the nearest mile post.
Updated September 2022
Mile 0 Utah/Colorado border.
Mile 1 Morrison and Dakota sandstones.
Exit 2 Rabbit Valley; great descriptive trail through the Morrison; numerous dinosaur bones can be seen, including a fine Camarasaurus skeleton only 5 minutes up the hill. Area well described in an article in the Dinosaur Triangle guidebook.
Miles 3-4 Massive fluvial sands in the Morrison Salt Wash Member?. (Brushy Basin Member in this area is very shale rich).
Miles 5-7 Road at Dakota level; Watch for Lytle (Here called Buckhorn/Cedar Mountain thesis work is by Currie).
Mile 9 Coals in Dakota
Exit 11 Mack; route to P valley and Mancos B outcrops
Mile 12 Dakota hogback to south
Exit 15 Loma, road north to Rangeley and Douglas Creek Arch
Mile 17 Cross Colorado River twice.
Colorado National Monument to south; best data including a very nice strat column are in Lohman, 1960 Weimer and Haun eds; Geol of Colorado; p. 86-91.
Exit 19 Fruita, Dinosaur Museum at Devil's Canyon.
Exit 24 Redlands Parkway
Exit 31 Grand Junction; Horizon Drive, airport is to north.
Mile 34 Cozette sandstone forms skyline to north.
Grand Mesa to SE is capped by resistant lava flows.
Exit 37 Clifton
Mile 38 note slumps on flank of palisade to north.
Do these represent vestigial equilibrium surfaces?
Mile 41 Vinyards to south
Exit 42 Palisade
Exit 44 West Palisade
Exit 46 Cameo Coal mine and power plant (site).
Exit 49 Route 65 to Colburn and over Grand Mesa to south.Roller dam to north sets up the Grand Canal that irrigates the terraces above Grand Junction.
Mile 51.5 Fresh landslide falling in from south (Spring 2000).
Mile 58 Valley opens up into hay fields and splendid panoramas to north of the eastern fringes of the Unita Lake system with its contained oil shales.
Exit 62 DeBeque
Mile 63 Cross Colorado River
Mile 65.5 Garfield/Mesa County Line
Mile 66 Note red stripe to north in Wasatch; lake beds are above in shades of olive.
Mile 70 Great fluvial Wasatch o/c to north. Some of the best isolated channel sand outcrops in the region. To the south note the flights of terraces recording the downcutting history of the Colorado River.
Mile 72 Channel sandstones at road level, lake beds halfway up cliff
See a couple of publications bought in GJ dealing with the oil shale mining projects.
Mile 74 Parachute City Limits!
Exit 75 Parachute elev.5095’ (pop. 250) Battlement Mesa (pop. 2134). To south on terraces are the retirement communities built in the Exxon company town that was abandoned May 2, 1982 (known locally as Black Friday) after Exxon decided not to develop the oil shales. Unocal built a 10,000 barrel per day retort plant north of the road here in 1983. During 8 years of operation this plant yielded 4.5 million barrels of 34 API oil. This is the largest shale-oil effort in US history but was abandoned in 1991 because it was uneconomic. The main interval being mined and retorted is the Long Ridge zone. This zone contains 34 gallons of recoverable oil per ton of shale. It is estimated that the retortable oil in this zone is 1.6 billion barrels. Local Coal stratigraphy: See: 1991 RMAG Coal bed methane of North America vol. (black one); Note figure 5 on p. 6 for strata south of the road, and fig 6 p. 215 for an E-W section going from Parachute to the east.
Local Coal stratigraphy: See: 1991 RMAG Coalbed methane of North America vol. (black one); Note figure 5 on p. 6 for strata south of the road, and fig 6 p. 215 for an EW section going form Parachute to the east.
Mile 76 High escarpment to north has a buff upper and a variegated lower slope--represents land to lake transition.
Mile 80 Note small channels to north.
Exit 81 Rulisson, Variegated beds of the Wasatch to the north; note channels and trough cross beds. Well developed terraces to the south. Several miles south of here the government tested a 40 kiloton nuclear bomb underground in an attempt to fracture a tight gas reservoir. Reports were that the little bit of gas obtained was contaminated with radioactivity and such efforts were put on hold.
Mile 82 Excellent channels to north
Mile 84 Excellent channels to north in amphitheater with many CBM wells. Roan Plateau to north.
Exit 87 Rt 13 north to Meeker
Mile 88 Cross Colorado River, sand and gravel pits to north
Exit 90 Rifle elev. 5345’
Exit 97 Silt elev. 5432’
Mile 99 Leaving the Piceance Basin
Exit 105 Newcastle
Exit 111 South Canyon. Excellent exposures of the Permian through Upper Cretaceous strata. At the base are the red beds of the Minturn/Maroon fms. overlain in sequence by the Weber (Schoolhouse Tongue), State Bridge (Permian), Chinle (Triassic), Entrada (Upper Jurassic), Morrison (Upper Jurassic) and Dakota Sandstone. A thin grey fossiliferous dolomitic limestone, the South Canyon Creek Member, is present in the middle of the State Bridge Fm.
Exit 114 W. Glenwood Springs
Exit 116 Glenwood Springs, Aspen cutoff. Swimming pool on north, with hot springs emanating from the karsted Mississippian surface. Yampah Hot Springs vapor caves in karst caverns.
Enter Glenwood Canyon.
Mile 118 at end of tunnel.
Exit 119 No Name rest area. Fabulous views of the karsted surface of the top of the Mississippian Leadville Limestone.
Exit 121 Grizzly Creek, elegant rest area
Cross fault enter basement
Mile 122.8 Shoshone power plant, Two pipes carry 1250 cubic feet per second of Colorado River water (deflected from the river near mile post 125) down a 165 foot drop. This generates 15 mw of electricity. This is a simple ‘run of the river’ power plant. The turbines were installed in 1906 and are owned by Xcel. The water use is based on a 1902 water right. This is the senior water right in this region; it requires that all upstream users allow at least this much instream flow. By maintaining flows of at least this amount, fish habitats are preserved and natural saline springs are diluted ensuring water quality for downstream irrigators. Along the 2-3 mile stretch of river above the power plant very low, to no-flow conditions may occur in the summer. Below the plant, rafters revel.
Exit 123 Shoshone
Mile 124 Views of basal Sawatch sands on basement high on all sides.
Exit 125 Hanging Lake. Plunge into sinuous tunnel in granite, note lots of rock bolts. Tunnel curls to north and pops you out right at basal unconformity on mile 126. Thin bedded Sawatch quarztites sitting calmly on the basement. Westbound lane pops out of its tunnel and climbs flyway, we proceed east along river.
Mile 127 Laminate Pz carbonates, westbound road in tunnel.
128
Exit 129 Bair Ranch and extensive parking area.
129.5 Sawatch at road level, river again is full.
130.5 Eagle County line
Mile 130.6 Tower karst visible across the river at top of Mississippian strata. Valley opens out into sage flats. Gypsum and shale beds to north, juniper mantled shale to the south.
132 Bedded Eagle Basin dark shale is well exposed across river to south.
132.8 Suspension bridge across river
Exit 133 Dotsero; the Colorado River arrives from the north and joins the Eagle River
Mile 134 Aa lava flows ahead on south of road. In spring 2000 the lava flow is being flattened out!! Volcano on north, nice stratigraphy on south. The cinder cone is 4150 years old.
Mile 134.5 volcano N of road, behind cinder quarry amidst gypsum.
135 Contorted gypsum beds to north.
136 Watch for dips indicating a river anticline in this area
Mile 137 Evaporite facies changes into Minturn/Maroon
Mile 138 Black streaks of shale inter-laminated with gypsum.
Exit 140 Gypsum: road to north leads to massive quarry, not visible from road.
Miles 141-
142 Excellent cliffs to north comprised of gnarly contorted evaporites.
142.8 Beautiful imbricated conglomerate beds on median.
Exit 147 Eagle, elev. 6600. Eagle County Regional Airport and Hardscrabble Mt to south.
Mile 153 Entrada Sandstone on skyline to north. The Schoolhouse Tongue of the Maroon is thinning and eventually pinching out. Thus unit thickens behind to become the Weber Sandstone. The marker bed (stained by hydrocarbons?) defines the top of the Maroon and base of the State Bridge. After it pinches out the boundary between these two units is difficult to discern.
Mile 153.5 Dakota on skyline to north.
Mile 154 Bridge over the Eagle River. Outcrops on NW at road level are State Bridge Fm. These are overlain by the Gartra Conglomerate bed (resistant ledge mid way up the cliff; contains sub angular quartz clasts to 5 cm) this bed defines the base of the orange Chinle Fm; At the top of the hill is the salmon colored eolian Entrada Sandstone (Entrada equivalent).
Mile 156 Excellent Dakota outcrop on road to south.
Exit 157 Walcott
159 Minturn/Maroon to south
Mile 160 Vertical beds to north; abrupt dip change as you enter a tight fold that is well exposed north and west of Wilmore Lake. Near vertical beds whip out of the Mintun / Maroon strata giving a rapid climb up section through the orange colored State Bridge and Chinle formations capped by the eolian Jurassic Entrada Sandstone.The Entrada is overlain by the Morrison, then the Dakota sandstone. These are overlain by the dark Cretaceous marine shales. Cross Eagle River: Look immediately north: Excellent Dakota on Morrison exposures; now enter a Cretaceous dark shale valley at mile 158; gray beds to north are the Niobrara carbonate-rich units.
Mile 161 Massive trailers and subdivisions being built on the south side of the river.
Exit 163 Edwards.
Exit 167 Avon.
Exit 169 Eagle Vail
Mile 170 In landslide.
Exit 171 Minturn and Battle Mountain. Here is where John Karachewski did his work on the Minturn fm. To the south can be seen the Lion's Head, a carbonate reef in the clastic dominated Minturn/Maroon fm.
Landslide on south where the entire area is slumping to north against the river.
Proceed through good exposures of Minturn/Maroon fms. as you enter the Vail valley.
Mile 173 Enter narrow canyon in M/M. These well bedded fluvial and deltaic deposits can be seen to north, no stopping on interstate. There is carbonized oil (graphitic) in some of the strata at road level.
Exit 173 West Vail exit.
Exit 176 Vail exit with Colorado Ski Museum
177 Ledges of Minturn/Maroon make the staged Black runs at Vail.
178 Undercut landslides on north side of road.
Exit 180 East Vail
181.5 Views of Gore Fault up drainage to NE, this is where you come down after hiking in from Red Buffalo Pass
Mile 188 Approaching summit, coarse Minturn /Maroon outcrops
189.5 Vail Summit elev. 10,603'
190 Rest area and cut-off to Shrine pass and Red Cliff
191 Copper Mountain hoving into view.
Exit 185 Copper Mountain.
Mile 200 Look for glacier sculpted rocks
200.5 Great glacial striae and polish.
Exit 201 Frisco and Breckenridge
Exit 203 Frisco exit and Dillon reservoir spreads out to the north. Grouse mountain ahead (see the grouse?)
Dillon Reservoir to South, Good o/c of basal Dakota, above the Morrison, no Lyttle to speak of.
Exit 205 Dillon, Silverthorne. Road north to Kremmling along the Blue River
206 Silicified and thrust faulted Dakota Sandstone to north.
207 Granite thrust over Mancos Shale by the Williams Range / Elkhorn thrust fault.
212.2-213 Road collapsing into gorge on large arcuate failure
Eisenhower tunnel elev. 11,158'
Exit 221 Bakerville; access to Grays and Torrey peaks to south.
225 Old granite quarry on north side of road; rock and ice climbing.
Exit 226 Silver Plume elev. 9118’, home to Plume Saloon and the Pelican mine.
226 Precarious corner with rocks sliding continually
Exit 228 Georgetown elev. 8519’, Watch for mountain sheep.
Mile 229 Ice fishing lake
Exit 232 Empire, Beyond Empire on road to Jones Pass, is the underground Henderson molybdenum mine (Wallace et al., 1978) producing 10-30 million pounds of moly/year. In Empire, the Peck House offers ghosts and Sunday brunch, Route 40 heads up over Berthoud Pass to the Winter Park ski area and Middle Park. The ridge dividing the Empire valley from the Georgetown valley was overtopped by ice as this U shaped valley was carved.
Exit 234 Downiville 5 cent coffee. Watch for elk on road near dusk
Exits 241
A&B Idaho Springs Note water wheel on south and Argo Mill tailings on the north. The Argo tunnel connects this area with the Black Hawk / Central City area and served to drain water and carry ore from these mining districts to the north. To the south is the Indian Hot Springs spa; features banana trees in a large glass enclosed pool and subterranean hot vapor rooms.
Mile 242.2 Tunnel; bridge to south dedicated to the high school student eaten by a mountain lion in the 1980’s.
Exit 243 Hidden Valley, Casino Parkway
Exit 244 Precarious left exit; Rt 6 and Golden, follows Clear Creek drainage.
Mile 246.5 Summit of Floyd Hill
Exit 248 Beaver Brook and Floyd Hill
Exit 253 Chief Hosa, look for buffalo herd
Exit 254 Genessee Park
Exit 256 Buffalo Bill’s grave
Exit 259 Morrison town is located to south a few miles.
Cherry Gulch landslide is visible to the south as a high bench armored by slabs of Fountain fm from a collapsed flat-iron. Large park and ride lots are present at this exit. TRex is to NE, Wooly Mammoth to NW. Field trips often gather here. As you climb the hill, exposures of Precambrian metamorphic rock collectively termed the Idaho Springs Formation are visible to the north. These develop into excellent roadcuts showing various gneissic and schistose textures cut by pegmatite dikes.
Mile 258 Roadcut through the Morrison and Dakota formations.
This famous locality exposes the Dakota and Morrison formations in great splendor. LeRoy and Weimer (1971) published a one sheet description of the strata as exposed on both sides of the highway. To the south the hogback is known as Dinosaur Ridge, named after the bones exposed in the Morrison Formation and the trackways on the top of the Dakota Sandstone that holds up the resistant ridge. Note the wind gap, a former course of Mt Vernon Creek. An easily accessible trail along the hogback reveals granite pebbles and cobbles in this notch.
Here we emerge from the Rocky Mountains, onto the High Plains.
City of Denver looms ahead.
Rt. 285 Westbound Mile Markers
Rt. 285: Denver to Poncha Pass
Intersection of University and Hampden (Rt 285)
Time to Kenosha Pass: 1 hr 25 minutes.
257: Sheridan
252.4: Mt Carbon on north, note Prairie Dog colony. Knoll is capped by a granite conglomerate with clasts over 1 m in diameter.
250.5: Intersection with C-470
250: Pass through Turkey Creek watergap in the Dakota hogback. Note oil seep, uranium roll front, and molybdenum blooms in the D sandstone.
Cretaceous sequence here is: Lytle with pebbles; on Morrison, overlain by Plainview, overlain by Skull Creek, overlain by Horsetooth member (shallowing upwards), overlain by Kessler incised fluvial channel in turn overlain by the Mowry Trangressive Surface of Erosion.
Descending section you pass through the valley-forming Ralston Creek (base of Morrison), the Triassic Lykins, the Permian Lyons, and the Penn-Perm Fountain formations. The Fountain rests unconformably on the Precambrian basement which is the Idaho Springs formation (1.75 Billion yrs.). The sediment-basement contact can be clearly seen on the north side of the road.
246.5: Indian Cave, visible in gneiss over road to west. Excavated by DMNH.
246: Parmalee Gulch Road
245: Wonderful pegmatite outcrops in roadcut
244: North Turkey Creek Road
241: Windy Point: Granite of the Doublehead pluton dated at 1.24 BY.
Double Header Ranch Road
238.5: Meyer Ranch: Old Victorian house, no longer an airplane in barn, landing strip on hill behind house. Look for balanced rock and landslide scar.
237.5: Aspen Park
236: Conifer
Highway 73 junction, Safeway, road to north joins I-70.
235.2: Foxton Road cutoff.
233: View of Kenosha Range to south: note accordant surface.
232: Shaffer's Crossing: the old Denver/Leadville stage crossed at this site. Just across Elk creek the Reynolds gang held up the stage getting a large and heavy booty of gold. This gang was trying to get money for the Confederate cause. A posse was formed and they were hunted down and hung --but the gold was never found. The last member of the gang as he was being hung, admitted that the gold had been stashed under a tree near timber line with a broken off knife in the tree indicating the spot. A forest fire later burned down the tree and people have been searching for the gold ever since.
229: Pine Junction Country store and post office.; note grus quarry to south. Jefferson County/ Park County line. On the north of the road, opposite log office building, note the ancient boulder beds. These are thought by USGS to be Eocene? valley bottom gravels. What do you think?
225.5: Horn Cemetery on south side of road. It is reported that this is where an unsuccessful local robber died after crawling away from the Deer Creek valley stage stop he was trying to hold up. He expired on the spot, inaugurating the cemetery.
225: Hog Heaven BBQ.
223.5: Crow Hill: Precambrian metamorphics along road; ptygmatic folding common, granite sweating out of the well bedded metamorphosed sedimentary rocks
222: Bailey, here the highway joins and follows the North Fork of the South Platte River for several miles in a WNW direction. The Kenosha mountains are south of the rivers. Note high gravels along stream margin. William Bailey established a hotel and stage stop here in 1864. Bailey was a station on the Denver, South Park, and Pacific railroad, whose rail bed the road follows all the way to near Poncha Pass. The tracks were laid out of Denver in 1878, and the intention was to go to the Pacific Ocean. It ultimately ended in Gunnison. Parts of highway 285 were built directly on the old rail bed, but traces of the old railroad grade can still be seen near Kenosha Pass.
218.5: Platte Canyon High School, Middle school ahead.
Cross North Fork of the South Platte River
Ice ponds: these shallow ponds were used to collect ice for sale in Denver. The ice loading chutes were still present on pond edges in 2000.
217.5: Shawnee Trading Post; Mt Logan (12,871') at 1:00.
216: Pleistocene (or older) gravels on south in small quarry.
215: Ben Tyler Trailhead on south.
213: Santa Maria
Pleistocene gravels
211: Grant: Road to north is Geneva Creek Road to Georgetown (24 mi.)
210: East portal of the Harry D. Roberts tunnel, built in 1962, bringing water beneath the continental divide from Dillon Reservoir into the Denver municipal water system.
206: Note railroad grade on north of road; in this area a marble marker commemorates the day when the train rolled off the tracks and killed a bunch of train people.
203.5: Kenosha Pass (elev 10,000 feet): Map in Weimer and Huan 1960, shows Morrison Fm. o/c on road (about mile 201.9) descending into South Park. Elkhorn thrust visible to southeast defining eastern margin of South Park. Nice bristlecone pines here.
5 minutes to Cow Rock
20 minutes to Fairplay
45 minutes to Trout Creek Pass
200: Lost Creek cut-off to the east.
199: Jefferson. Approx. 1 mile west is the axis of the Michigan Hill syncline which is reported to harbor several thousand feet of the Tertiary South Park Fm. Note train depot on right.
198: Outcrop of sandstone?? to northwest of road. This is South Park formation.
195: Coal mines east of road in Laramie Fm. Mines are collapsing, scattered sandstone and coal samples available, no good outcrops here.
Old square built stone ranch house to west.
194: Cross Taryall Creek
193: Road on Como terrace surface, forested ridge to south is Reineker Ridge. This ridge is made up of South Park formation and is held up by the Paleocene andesite flows and agglomerates of the Lower South Park Formation.
192.1 Elk Horn road to east, to Indian Mountain.
192: Como and Boreas Pass to west, Rt 33.
191.5: Pierre Shale outcrop
191.2 Paleocene (?) sills in Pierre Shale are holding up hill.
189.3: Outcrops of andesite lava flows and agglomerates in roadcut to south.
189.2: Safari Ranch Resort road to south, to north, Ned Sterne measured a 119 foot section in the shale and documented the Apache Creek Sandstone.
187.8: Cow Rock
187: Traversing dip face slabs in the Dakota. No Lytle pebbles.
Red Hill: Dakota hogback with poorly exposed Morrison Formation and massive Garo Sandstone. Morrison here is partially made up of clean limestones. No bones. Gastroliths evident on detailed inspection of outcrops.
186: Descend flank of Red Hill, Maroon Formation. Peat deposits ahead on valley floor.
183: Fairplay. In 1871 the town cemetery held 22 graves only three of whose occupants died of natural causes. (Simmons p. 153) In 1873 Dr. F.V. Hayden's USGS party including Wm. H Jackson photographer stopped in town. Note large tailings piles and absent dredge southeast of town.
178.3 Weston Pass Rd to west
177.5 odd dead trees to west
176: Log house construction business
174.5-174: Pleistocene fen or tarn to east.
171.5: another fen
170: Garo sandstone outcrop
167.2 RV Park and campground, a few sites available!
167: red beds in road cut
165: Road starts a 3.5 mile straight-away that takes you across the Salt Creek flats, past Paul Bunyan's Butt on south and heads to the crest of Trout Creek Pass on the northern extent of Kaufman Ridge.
163.5: Salt Creek and Paul Bunyan's Butt to SE. Augusta Tabor stayed here.
161.8 Junction with Route 24; Belden Shale
CHANGE MILEAGE SYSTEMS ON ROAD MARKERS
225.5 Chaffee County Line, Trout Creek Pass Summit in low relief Belden Shale.
224: Driving south along eastern margin of a Belden strike valley with RR grade. Note mine/quarry ahead.
221.5 Cross Trout Creek at famous Basement contact; see 1960 green Weimer and Haun Guide to Geology of Colorado for map and labeled photo p.146,147 of this spot. Above and to the west is a mineralized weakly karstified dip-slope that has been heavily prospected. The Belden Shale is being eroded off and the hill side is a druzy silicified dip slope.
Rails over pass were abandoned in 1926 (Simmons, p.175).
219: Trout City with mini railroad.
217.2: Beaver dams to south also dark ridge of Oligocene ignimbrite. This is the Wall Mountain Tuff.
214.6 Turn off to north to overview of Arkansas Valley
213.5 Cross Arkansas River
213: Johnson Corner
212.8: T intersection with Rt. 24: Turn South.
CHANGE MILEAGE SYSTEM ON ROAD MARKERS
147.5: Intersection w. Rt 24
147: Gravel quarry to W
144.5: Raft center on east
144: Note Basement outcrop to east at margin of basin; onlapping seds.
143.1: Cooling joints in cockscomb hill to east marks an intrusive center.
143: Nathrop
142.4: Mt Princeton cutoff, note white cliffs at base; these are the altered granite at the Mt Princeton hot springs. The granite is the Mount Princeton batholith dated at 36.7 Million years identical to the Wall Mountain Tuff.
141.8 Pagoda style house
140: Two pipe crossing in till and terrace; Mt Antero (14289') to west.
138.5: Centerville with ash in three pipe crossing. Bishop Tuff from Long Valley Caldera south of Mono Lake, CA on both sides of road and in quarry face on NE side of outcrops.
138: Free gold panning
136: Fluorite mines to east
135: Cattle Baron restaurant, frequently closed...
134: Salida cutoff to east.
132: Pt of Interest: Christmas 1806
Mt Shavano to west
131: Dissected bluffs of Dry Union Fm to west.
128: Salida airport to NE
127: Intersection with Rt 50 at Salida Jct. Turn east.
Note the beveled terrace surface weakly preserved south of Salida. This represents a fill stand in the Upper Arkansas Basin fill that is presently being heavily dissected.
Pagosa Springs: Jackson Hotel and Grimo's Italian restaurant.
Prepare to enter the transfer zone between two major strands of the Rio Grande Rift!
125.5 Note sediments against basement on right.
125: Note shattered basement outcrop
Note sediments on top of volcanics, whole business tilted.
Road off to Marshall Pass
120.8: Fractured basement with sheens of epidote on slicked surfaces.
120: Mica mine
119: Poncha Pass, 9010'.
Van Alstine of the USGS did the geologic mapping in this area.
Rt. 40 Northbound Mile Markers
Rt. 40: Empire to Granby
Turn of I-70 at Exit 232 to and head north on Route 40
257 Empire elev. 8602 is the site of the Peck House, Jenny's and a rich mining history.
249 Berthoud Falls, a small mining town.
Henderson Molybdenum Mine is located south of Jones Pass.
Ore is mined through block stopping and is transported by conveyor across the continental divide towards Kremmling.
South side of the pass has beautiful views of rock avalanches in large bowl to the south.
244 Beautiful view of cirque to south with relict ground moraines.
Berthoud Pass Summit, switch backs up both sides.
Beautiful view of the summit of the Indian Peaks Range and Rollins Pass (across which a railroad used to traverse before Moffat tunnel was built). Note that the range had extensive glaciers on the east side in a series of well developed cirques and bowls, whereas west side of range had almost no glaciers. This is due to the prevailing east-blowing winds carrying snow over the range crests and dumping it on the east side as well as the tendency for the western facing slopes to be warmer.
237 hairpin turns
Mary Jane ski area.
233 Winter Park Ski Area, Moffat tunnel and water siphon emerge here. Basement of Meta seds.
Winter Park.
Fraser (elev. 8550) icebox of the nation, is virtually contiguous with Winter Park, snowmobile racing.
Entering the south margin of Middle Park, an ill-defined low lying area of clear structural affinity to North Park.
Pleistocene ? lake floor with etched moraine margins. Good views of ski trails at Winter Park.
Sediments immediately south of town.
Tabernash.
Just North of town on N side of road, Small road-cuts in Miocene(?) ashy looking sediments. Troublesome Formation (?) type unconsolidated sediments.
Pole Creek
Outcrop of basement grussified
Snow Mountain Ranch YMCA on southwest.
219 Morrison outcrops on NE of road.
218 Massive basement outcrop.
Morrison sliver. More Precambrian outcrop, foliated and sheared in a series of roadcuts on east side of road.
drop out onto north end of Middle Park, elegant panoramic view.....
Ore Ranch on left. Mantled slopes on right suggest a (K) shale;
216 Note red beds to top on switchback road to east are the Morrison Formation.
Note terrace levels , Road at mile 215 is on a low, young terrace.
Ski area to east.
Lake beds immediately to the west.
213 Granby elev. 7935.
Nice wide street town.
2 Hours out of Denver if no traffic.
Rt. 125 Northbound Mile Markers
Rt. 125: From the Junction of Routes 40 and 125 to Wyoming state line.
Mile 0 Turn right on Rt 125 to north.
Pebbly volcanic rich troublesome type o/c at intersection.
Proceed north on route 125 into an area seen from the air to have thick Cretaceous sediments.
2 View to south of the north side of Middle Park.
3 Hay meadows and nice view ot the SE of the Indian Peak Range?
5 Agglomerate volcanic cliffs past narrow bridge.
Moose country
Sediments and layered volcanics are poorly exposed throughout this area, need detailed map to suss out patterns. Sediments are very volcanic-rich
Road 408 on E, outcrops of sandstones tilted down to north, may be Dakota?? O/L by volc rich seds (draped over Cretaceous?)
11 More seds in poor o/c to east
r/c of flatlying Cret seds?
12 Willow flats narrows to the north.
Climb on to north, rocks are volcanic??
Dike of tremendous wall like nature comes down close to road hole in rock wall.
2 miles to Pass sign, well wooded country affords few outcrops.
Yet seds of Cretaceous character are evident with dikes cross cutting; together with pods of volc clastics
Main Dike wall with small quarry at road level. (sampled)
Willow Creek Pass summit 9683.
Never Summer Range views to NE
Descend towards Walden and North Park
23 o/c of possible Cretaceous non-marine, w/ channel on west.
24 Continues poorly exposed series of probable Cretaceous marine shales and o/l (?) non- marine units
Could be Tertiary, small channels and paleosols are present in road-cuts.
Routt Nat'l Forest Boundary
27 Old lake bottom to left
29 Old Homestead Lodge and Cabins
30 Pop dramatically out of trees onto the flats; this is North Park!
Note terraces
Rand bitsy, Rand Store, closed in winter, but good snake skins in summer.
Hay fields on bottom land; Medicine Bows to North, North end of Never Summer range to east
Light colored seds peek out of terrace bluffs in a few places. Could some of this be Miocene?
Cross Willow Creek in small dip.
36 Low mantled hills to east have a Cretaceous character but could well be Tertiary.
Occasional pale bedding is visible, could be ashy. Rabbit ears visible to west in distance on skyline.
Modern terraces are quite horizontal but there may be some high east tilted terraces, need air photo to sort out.
40 Lots of cows here in December 94, winter feeding.
41 Note the bluff to the east, 500 m of sediments of ? age.
42 Arapahoe National Wildlife Refuge to east
Climb onto higher terrace, slightly tilted to NE
46 Wildlife refuge on flats to east
Good views of Medicine Bow Mts. to east with tree line well defined; to west Park range rises with less prominence, some low saddles separate the just barely above timberline crests, Portions appear sedimentary.
51 Cut off to Muddy Pass, Steamboat and Kremmling,
Curve in road and enter suburban Walden.
Cross Illinois River saw mill
Walden elev 8099
Gas available, Coffee pot cafe
Cross Michigan River, Outcrops of major shallowing up marine sand immediately north of town on north side of river, good exposure in road-cut through bluff, should have ichnofacies to determine env't of deposition.
55 More sage flats......
58 Pumping oil well to east 1 km
59 major power line crossing
61 Medicine Bow Range loosing elevation to north
cut-off to west to Cowdrey Lake, no lake to be seen...
62 Cowdrey town, Post office and general store.
Approaching edge of Park; road carves into seds and resistant tree covered ridge after passing Laramie 127 intersection
(Saratoga 55 miles Rawlins 96 miles)
67 State Line Ranch
Red seds (Could be Pen Perm?) and basement on basin flank
68 on basement
crossing basement spur, North Platte River crossing
70 Note planed Precambrian surface to east
mile 71
mile 72 style to e, on basement too dark to see.....
State Line road character changes, mile 127 mile markers on west. Road is on east side of a low relief (filled) basin.
Rt. 9 Southbound Mile Markers
Rt. 9: Kremmling to Silverthorne
Mile 139 T-junction with Rt. 40. North of town is a lovely outcrop rim of the Kremmling sandstone.
Mile 138 South outskirts of Kremmling
Pass Middle Park Meat Company.
Follow then cross the railroad tracks and head due south.
Mile 137: Cross the Colorado River; note deep gorge to west.
Excellent outcrops of black Cretaceous shale.
Mile 136: Gravels in r/c to west are high stream gravels.
High bluffs of sandy Cretaceous shales to east.
Broad valley heads due south. This broad valley must be structurally controlled.
Mile 134 Blue Valley Ranch to west. Driving rth there are peculiar pa
135 Niobrara carbonate shales in river to west.
Mile 130 Gnarly ridge of Cretaceous shale to east --or is it a dike??
What is best map of this valley?
Mile 129 Near here pick up on Ven Barclay's map
Mile 128.5 Spring Creek Road cuts off to west.
Mile 127.5 Williams Peak Road cuts off to east.
Mile 127.5 Grand County Line
Mile 127: Williams Mts. to east are all Cretaceous… with a thrust at the top???
Mile 126: Green Mt Reservoir dam and Heeney to west.
Black Cretaceous shales with veneer of brown weathered colluvium.
Reservoir is to west.
Miles 121-125: Reservoir to west; excellent massive outcrops of black Mancos Shale with 2-4cm bands of orange-yellow ash.
Mile 120 Upper reaches of the Green Mountain Reservoir.
118.4 Badger Bluff Ranch to east.
118.2 Cross Blue Creek
Mile 118 Heeney cut off to west
Mile 117 Broad flat, possibly pooled behind moraine (need to look at an air photo)
Mile 116.4 Mt Powell Ranch
Mile 116 Are these moraines or incredibly poorly sorted terrace gravels? Excavations made to widen road in 2003 show moraine facies. Glaciers probably spawned from the east flank of the Gore Range.
Mile 115 Stream bottom shows a gallery forest. Pass Creek ranch to east. Large massif to east of Mancos Shale
Mile 114.2 Henderson Mill cut-off to east.
Mile 112 Blue River follows road.
Mile 111.2 Moraine to west.
Mile 109 Valley narrows and grade increases. Morainal clogging is likely cause.
Blue River Nat'l Forest Campground
Roche Creek
Mile 107 Gravel quarries, soon to be landscaped for urban sprawl.
Mile 106.5 Sand and gravel operation to west.
Mile 105 Terraces high on east side of valley??
Mile 104 Silverthorne town limits.
approx. Mile 102 Interstate 70.
Rt. 145 Eastbound Mile Markers
Rt. 145: Cortez to intersection with Rt. 62
Proceed north from east side of Cortez
Cross flats of Mancos shale lying in resistant Dakota surface.
Pass the Mountain View B&B; fine views of Mesa Verde to the south, San Juan Mts. to the East and Sleeping Ute to the Southwest.
McPhee Reservoir.
The Anasazi Heritage Center is off to the west on Rt. 184 about 1 mile. This is the best museum in the region and absolutely worth a stop.
Mile 11.5 Dolores, elevation 6936 feet.
Dolores. On the wall north of town is the Morrison with basal Cretaceous (Dakota) unconformity. Road up the face leads to Disappointment Valley.
Proceed NE on Rt. 145.
Turn left at Trailside General Store to get to Disappointment
Road to Telluride 68 miles proceeds east up valley floor.
Mile 12 edge of town
Lilacs are great here in early June.
Mile 15 outcrops of Dakota group form falaises along valley walls, generally rather vegetated.
Mile 16.4: Outcrop of Morrison; Dakota sandstone forms cliff to west.
Mile 17-19: Outcrops of massive eolian Entrada sandstone in roadcuts and as buttresses emerging from pine covered slopes across the river to the south. Entrada Sandstone at about mile 18-19.
Mile 21: Ponds from gravel quarrying to east.
Mile 22: Rounded white Entrada sandstone with great eolian crossbeds
Mile 22.5: First red beds of Cutler/MM/system below Entrada.
Mile 23.8: West Dolores Cutoff---hiking with Doug and Rachel et al.
Mile 26: Great rim of Entrada to north, with underlying PenPerm Where are the Triassic Redbeds?
Mile 32: Blend of Aspen and pines on hills to south; Red beds generally covered by vegetation, massive o/c at Bear Ck.
Mile 34: Bear Creek Trail access point.
Mile 34-35: Fluvial red beds in r/c on north. Note flat bedding, little incision thin bedded sandy character, paucity of overbank mudstone.
Mile 35.5: Priest Creek. A campground RV area.
Mile 36.2: Circle K Ranch.
Mile 37.1: Hillside drive road to south, forest access.
Mile 37.5: Good channels cutting into finer grained o/b deposits in r/c on NW side of road.
Mile 38.5: Roaring Fork road to south.
Mile 39: Good o/c of channels again in r/c. Note there are no carbonates in this suite of Cutler.
Mile 41.6: Cross Dolores river; Cutler still in fine grained facies.
Mile 42.9: Dolores/Montezuma County line.
Mile 43: Dike on south?
Mile 44.2? Scotch Creek Enter into a massive pale intrusive rock. What is relationship to the Cutler??
Mile 45.5: Tailings in creek
Mile 45.8: Straw houses to right.
Mile 46.2: Rico; Rico Hotel. Enterprise Bar and Cafe estbl. in 1892.
Cross Dolores Creek
Mile 48 Tailings in Creek, good o/c of pale bedded Cutler form massive prow to the NE above road. w/ altered intrusive or basement o/c. settling ponds in river valley tailings ponds, dandelion fields, aspen just getting leaves in June.
High cliffs of grey Hermosa Fm?? looks limey
Mile 50: Excellent outcrops. Cutler getting pebbly at road level!
Mile 52: Note facies of Cutler/Maroon: Grey over red on NW.
Mile 52.8: Coal Creek.
Mile 53.5: Barlow Creek National Forest access.
Mile 54: Dunton cutoff to north. Bleached beds immediately after cutoff. Are these against an igneous intrusive??
Mile 56: Sheep Mountain ahead to east; Elev. 13,188
Mile 57: Glacial and landslide hummocky terrain; Till and Cutler.
Mile 57.2: Tusk to west is Lizard Head Peak; v. impressive 13,113'
Mile 58 lots of snow here June 14 1995; none July 1, 1996
Mile 59 Splendid ridge to east probably of Cutler; low relief roadcuts of black shale
Top of Lizard Head pass, San Miguel co line and more black shale outcrops as you descend to the north!
Dolores/San Miguel County line
Black shale o/c Belden???
Yellow Mountain is the rampart to the east with considerable alteration evident.
Mile 60:
Mile 61: Gorgeous Trout Lake with lots of condos.
Dikes cutting black shale
Mines to west in avalanche chutes
Mile 63 Volcanics Large U shaped valley heads to NW
On spires to N intrusives have delaminated sediments
Large pipes cross
Mile 64: Massive wall of intrusive rock to NE, road cuts into cliff face ant wraps around the fine-grained intrusive. Back view of Lizard Head through north to the south.
Mile 64.9: Black shale o/c
Illium Ames acess amid tailings ponds and avalanche chutes and modern landslides.
Mile 65-66: Large igneous face to West with columnar joints and Belden at top Very similar to relationship at Leadville
Mile 66.2: Alta Lakes Road to east
Mile 66.4: Sunshine campground
Mile 67: Yuppie overflow from Telluride starts here.
Mile 69.5: Telluride Ski Ranch
Mile 70: new ski area; frantic construction in summer 95
Mile 71.2: Drop into valley floor; cross creek and encounter the Telluride cutoff also called 145; Telluride spigot
Last dollar road cuts off to north; valley floor constricts;
condos begin.....
Mile 1 Condos on left, flat yet to be developed valley to right south.
Cypress bog to right; Pleistocene bog
Telluride Cutoff; Telluride is 3 miles up Box canyon.
Placerville 12 miles ahead.
Mile 72-73 slides and till with Cutler flat-lying beds
Mile 79-75 Canyon walls to north have 800-1000 feet of red and greenish Cutler beds of fluvial flat bedded strata, no pebbles.
Mile 77.5 Silver Pick Road
Mile 80: Sawpit hamlet. Elev. 7554 ft.
Mile 81-2: Suburban Sawpit.
Mile 83.5: Placerville w/ M&M Mercantile and general store.
Mile 70-84: Purple to brown Cutler sediments; good outcrops along the length of this valley, occasional entire cliff faces are clean. Note the alternation of white and red. Is there oil staining in this area??
Mile 84 Intersection with route 62. Ridgeway is 22 miles.
Rt. 145 Westbound Mile Markers
Cross Creek, 16 miles to Telluride
Cutler on all sides
83.8 Placerville
83 Excellent Cutler r/c with thin dike
82.5 Blue Jay bar and café
81 Conglomerates!
Sawpit: fine grained redbeds
Nice scour-based sands well exposed in many r/c on east side of road
78: Climb up along Qal and shaly rich outcrops Could there be some Mancos in here? Junction with route to Dolores
3 miles to Telluride
Road log from Telluride Jct. to Dolores
68 miles to Dolores.
70: Black shales entrance to Telluride ski area.
All sorts of posh developments in this area, most are fairly well disguised.
Sunshine Mountain and Wilon Peaks view to southwest.
67: jagged ridge to SE
Alta Lakes Road
65: Black Shales, road falling in. Either Belden or Cretaceous shales
Fabulous flow massifs overhead on east of a tight corner with a sign for a post office. This appears to be a huge plug of igneous mat'l intruding shales.
Fine grained intrusive? in road-cuts
63.1 Old Butterfly rd.
Matterhorn Drive
61.4 Trout Lake cutoff to east.
59.5 Black shales at the Delores/San Miguel County line.
Crest of pass, low open area, tons of snow on March 30, 2000.
58.5 Pass by Sheep Mountain
57.5 Lizard Head spire to west
Drop down back into a pine wooded valley in the Cutler Fm.
55: Trough cross bedded fluvial sands.
53.8: Rt. 535 to Dunton is road to Chanterelles.
51-52 Great redbed o/c
49 Grey fluvial sands of the local Cutler
47.5 Cross the Dolres River and enter Rico
1892 Enterprise Bar and Grill on west is and awesome bldg.
46: Beaver ponds in lowlands of Dolores River.
43 Montezuma County line
42 Fine laminated fluvial sands and muds
39: Great red sandstone outcrop.
38.8 Roaring Fork Rd to east.
36-38 Many good outcrops of relatively fine grained redbeds.
36.2 Circle K Ranch
34: great trough cross beds
33.9: ALERT look at the color change from reds to greys here … is this a fault?
28 great fluvial sands
27: Beautiful sweep of Entrada Sandstone forms arch in front and sweeps around the west side of the valley!
26: Old ski area to east
24 Entrada
23.5 Cutoff to right
22.5 Eolian Entrada sandstone forms massive r/c on west. Exquisite o/c of toe sets of dunes (sure they aren't troughs?)
21: Water storage system in old gravel pits to east
17.5-18.5 Patch road-cuts in the Entrada. Clearly eoliams multimeter dune foresets.
17: Entrada dives below road level, we are in the Morrison.
16: Dakota forms sky line ahead.
14 In Morrison, outcrops are poor but it seem to be fluvial.
11.5 Enter Dolores 6936 feet. McPhee Reservoir Cutoff to west. Old Germany Restaurant
Junction 184, views of McPhee Reservoir to the right.
Sleeping Butte Mt hoves into sight and voila the Mesa Verde unfolds before you with Cortez at its feet.
Rt. 62 Eastbound Mile Markers
Mile 0.0: Proceed east on Route 62 up valley with Cutler on both valley walls, moderately good road-cut exposures and pine covered slopes. Taken together with the Telluride valley there are good three dimensional exposures of fluvial facies in this area. Strata tend to be paler to the top; often massive bedded multi-storied sandstones with individual channels about 1 meter thick at mile 2
Note Gilbert deltas at 2.2 on south side of road.
Reminds one of McCoy area.
Mile 3: Very white sands on south; later also on north.
Mile 4: Punky yellowish strata --still Cutler?
Mile 5 has a Morrison look to it
Mile 8 bedded cutler in scruffy road-cuts.
Mile 11: Proceed up Dallas Divide; Last Dollar road cuts off to the south; Mariposa Ranch is over-gated to the north.
Gorgeous views of snow-covered ridge to southeast
Mile 12: Crest of Dallas Divide. Note black shales w/ intrusive contact just on east side of divide.
Ouray / San Miguel County line
Views of West Elk mountains in distance to the north.
Long NS ridge defines sky line to east.
Igneous rocks and Belden shale outcrop just over summit on NE side of pass.
Curve down into valley at mile 15
Ridge of Dakota? forms low ridge to north.
Mile 16: Route 24 cutoff to north.
County Rt. 9 cutoff to south
Mile 18: reaching valley floor w/ barns and condos.
Road to north to a tire house (Dennis Weaver) and Bactrian camels and also dromedaries.
Log Hill village cutoff
Pierre shale o/c as you enter Ridgeway.
San Juan Momma's deli and bakery on South side of road before intersection.
Mile 23: Cross Uncomphagre River. Intersection with route 550 turns north towards Montrose.
To the east the jagged ridge line defining the town's name.
Silver Jack cut off to east
Dry Creek, Morrison outcrops in road cuts across from Ridgeway State Park.
Rt. 550 Northbound Mile Markers
Mile 106: Cross Ridgway Fault
Mile 107 Dakota Sandstone forms ridge-tops
Mile 108: Dakota outcrops, Ridgeway Park and lake on left.
Mile 109: Mancos Shale, Dakota, and Morrison on basement???
no basement exposed.
Mile 112: Pa Co Chu Puk Park. Cross Chaffee Creek, very unclear relations intrusives or possibly basement across stream to the west.
113.2 Cross Chaffee Creek
Mile 113.4: Cross Uncomphagre River, Morrison to east on basement or on intrusives.
Mile 114: Views to north of Grand Mesa through slot in Dakota outcrop.
Road runs along Morrison surface with Dakota on valley walls.
Proceed north and updip into broad expanse of Mancos.
Mile 115: Excellent Dakota o/c, note coal to NW.
Mile 117: Cross Wildcat creek suburbs of Colona
Mile 117.5: Montrose County line.
Uncomphagre uplift forms broad ridge to west, Grand Mesa forms skyline to north.
Mile 118: Transmission lines cross road
Mile 121.2: Site of Fort Crawford to west.
Mile 122: Broad flats of Mancos shale, pastures and irrigated farms with bluffs of Mancos on all sides. A yellow band is prominent to the NE and is either a sandy pediment surface or a sandy zone in the Mancos. There are outcrops to be looked at; however the lack of clear conformable character and the flat topped nature of the yellow ridges favors the pediment interpretation.
Mile 126: Chief Ouray and Chipeta Museum on south side of Montrose near river crossing. The museum has a modest collection of Ute memorabilia.
A sandy bluff of Mancos Shale occurs across road.
Mile 127: Enter Montrose. 5794 feet. There is a short cut around east side of town.
Walmarttacobellbigotires.........
Library has sculptures by Madeleine, famous marble sculptress.
Drive through a couple of miles of strip, then turn east on Route 50.
which is Main Street. Slowly extract oneself from Montrose, head east across a Mancos plain.
Rt. 550 Southbound Mile Markers
Head south out of Montrose on Route 550.
126: Cross river
Beautiful skyline of San Juans ahead.
125: old farmsteads on flatlands Rocky Hill Winery on east. Tasting room.
124 Rose Road
123.5 Solar Road
123: Mancos mountains to east
122: Raspberry Farm to w
121.2 Fort Crawford Site
120: Gravel pit to east; terrace gravels being extracted.
117: town of Colona
115.2 Elk farm and elk meat for sale
115 Outcrop of Dakota Sandstone ? form bluffs to east.
113: Bluffs of Sandstone to east, Uncomhagre River Crossing
111: great views of the jagged pinnacles to the south
109: Park to west: Ridgeway State Park, Dutch Charlie
108 Possible Niobrara road cut!
106.2 Morrison Outscrop to east
104.5 Ridgway city limit
103.8 Intersection w/ route to Telluride.
Rt. 50 Eastbound Mile Markers
Log heading east on Rt. 50 from Montrose to Gunnison
11 miles to Black Canyon.
Snow covered massif of San Juan Mountains forms skyline to the south. To the north the Precambrian is exposed shedding a veneer of Entrada, Morrison and Dakota.
Mile 98 Dark ridge to the east is the Precambrian massif emerging from the mantle of Mancos mud.
Mile 100.5: Cutoff to north to Black Canyon of the Gunnison National Park.. Established in 1999, it is six miles in and very worth while. Most impressive feature is the flat ancestral Rocky Mountain Uplift with Morrison on basement.
The new visitors’ center (built in 1998) overlooks the chasm. Dating of lavas, ashes and terrace gravels suggest canyon cutting has taken place in last 2 million years at a rate of 1 foot/1000 years. See booklet by Wally Hanson and detailed geologic map (2 sheets) by same.
East portal of Black Canyon route 347.
Mile 100: Mancos Shale on all sides.
Mile 101 The road now skirts the Black Canyon uplift, we drop down-section to the lower Mancos Shale.
Pediment surface to south of road is breached by headward erosion,
and forms the skyline.
Note landslides on slope to south.
Mile 105: Road collapsing into Mancos shale.
Road occupies strike valley to east with dark ridge of basement forming northern skyline. Basement is thrust to south over steeply dipping shales.
Mile 107.5 Cerro Summit
Mile 109-110 Basement ridge to north
Mile 111: Huge boulders of crystalline basement rolling into shale.
Mile 112: Cimarron has train exhibits and campground.
45 miles to Gunnison. Outcrops of Precambrian with “bedding”.
Mile 114: Landslides to south
Silver Jack reservoir cutoff to the south.
Stone House and Little Cimarron cutoff to south amidst herds of sheep
Mile 116.6: Gunnison/Montrose county line
Mile 118.4: Cross onto basement.
Mile 121.5: Up to an unnamed summit with snow in June of 1995.
Mile 123: Drop down and into the basement containing the Inn at Arrowhead. Note landslides of Mancos Shale.
Mile 124: Chasm in Precambrian
Mile 125.5: Volcanics to north.
Mile 126-8: Across valley to north note the absolutely flat unconformity of the Morrison and volcanics on basement.
Blue Mesa Reservoir is visible to north.
Mile 130: Dakota outcrop on south, unconsolidated.
Mile 131: Dam, Route 92 to north to Hotchkiss and Paonia.
Sapinero town and Morrison outcrops.
Mile 132: Cross strand of Blue Mesa Reservoir, it is full up Aug of 2008.
Mile 133: Morrison to south in Sapinero Village.
134-135: Views across reservoir to volcanics on Dakota over Morrison.
Mile 135.8: Lake City cutoff to south.
Mile 136.2: Bridge over reservoir.
Mile 136.4: Second Lake City cutoff number to south Route 26.
Cross reservoir on bridge with boats and fishermen.
Red Creek campground with West Elk volcanics forming cap rock.
Mile 137: Agglomerates to north
Mile 138: Dakota sandstone on Morrison.
Mile 139: Excellent Morrison outcrops with nice small steer-head channels.
Laminated limey Morrison mudstone is overlain by volcanics.
Route 149: Cutoff to Lake City, basement exposures.
Mile 139.8 Carbonaceous shales in Dakota.
Mile 141: Elk Creek Campground; it continues to south.
Mile 143: Volcanics on Morrison, Rainbow Lake cutoff to north.
Mile 147.5 Enter the Precambrian rocks carved by the Gunnison River Canyon.
Mile 150: Exit from the Precambrian gorge.
Mile 151: Cottonwood bottom lands.
Mile 154: Entering Gunnison flat valley and hay meadows; note o/c of ponded seds (?) to north. This looks like a Pleistocene lake basin.
Gunnison airport to south.
Gunnison. 7703 feet elev.
Broad Main Street.
Butch and Judy's tel. is 970-641-2907.
Log from Gunnison to Poncha Springs
Mile 158: Pioneer Museum
Mile 159: Gunnison Cemetery.
Mile 160: Volcanic agglomerates.
Mile 161: Dakota group sediments to north.
162-163: Morrison Formation with overlying lava flows.
Mile 164: Dakota Sandstone.
Mile 164.5: Precambrian basement.
Mile 165: Butch and Judy’s ranch with red roof on south side of road.
Mile 165.5: Route 114 cuts off to south to Saguache; it is 57 miles to Salida.
166-167: Precambrian outcrops.
Mile 169: Parlin, cut off to north to Ohio City.
170-171: Precambrian with Morrison on top. Look for conglomearates.
173-174: Hayfields in fertile bottomlands to south.
Mile 176: Cutoff to north to Waunita Hot Springs.
Mile 177: Doylesville and source of Yaks!
Mile 178: Conglomerates to north; river gravels.
Mile 181.5: Saguache/Gunnison Co Line.
Mile 183: Precambrian crystalline rock.
Mile 186: Eastern end of Gunnison Valley.
Mile 189: Sargents and cutoff for Marshall Pass Road to south.
Mile 190.5: Cutoff to White Pine to north.
Mile 199.2: Monarch Pass elevation 11,312 feet. Trail to north takes you to a ridge line with ancient sheep herding stone fences.
Mile 201: Monarch Ski Area.
Mile 203: Limestone quarry (?) to south of road.
Mile 204: Limestone to south. Manitou Dolomite?
Mile 205: Limestone to north Note contact with basement.
Mile 210.8: Maysville
Mile 215: Mega-breccias to south. (remember work by Van Alstine).
Mile 216: Poncha Springs, Intersection with Route 285 and road to Buena Vista, and Poncha Pass.
Rt. 160 Eastbound Mile Markers
103 Durango
104 Channel sandstone in Las Animas Fm.
197 Beaver ponds to south in Beaver Ck
111.5 Archuleta County line
116.5 Burned coal in Fruitland Fm..
118-119 Nice dip slope exposures of Lewis Shale on top of resistant Mesaverde sandstone.
121 Pictured Cliffs Ss to south of road (Equivalent to Fox Hills)
123 Lewis Shale
124-125 Chimney Rock to south, a BLM site. It is Pictured Cliffs Ss on Lewis Shale.
126 Lewis Shale o/c
127 Junction with Rt. 151
128.5 thin beds of Mv Group sandstone.
129-130 Mancos Shale
136 Dakota Ss
137-138 Road travels along resistant Dakota Group sandstones.
139 Edge of town
142 Dakota sandstone at road level.
143 Downtown Pagosa Springs Note Hot Springs. We are 45 minutes from Durango.
144.5, 147 Mancos Shale
149.5 San Juan River crossing
151.5 Landslides break road
152.5 Outcrop of Fruitland Fm ?
154 San Juan River crossing, look for moraines
156 Volcanics on north and south of road
158 Bottom of valley
158.5 Treasure Falls. Worth the stop to admire!
Road now climbs steeply up towards Wolf Creek Pass
159 Lava flows and lahar deposits
160.5 Hairpin turn
167 Summit of Pass with scenic views to west
168 Wolf Creek Ski Area
170 Fish Canyon Tuff (about 5000 km3)
172 Glaciated valley
175.5 Ice age architecture sign
176 Rest Area
180 Moon Valley Campground, Rio Grande County Line
184 Fish Canyon Tuff, base visible?
186 South Fork We are about 2 hours from Durango.
Rt. 62 Westbound Mile Markers
Telluride 37 miles ahead
Cross Uncomphagre river.
Climb west out of Ridgeway , camels to north.
22: Mancos shale
21: Ridge to north looks like Morrison with a crest of Dakota.
20: curl around mancos hill and gaze at the jagged San Juan edge.
18 bedded rock on either side of jagged intrusive center to south. We are in a Mancos valley.
17: still in Mancos, climbing towards Dallas Divide.
15: Switch-backing up a Mancos slope.
14: Sill ? in Mancos
Sandstone ledges in r/c may be Dakota?
San Miguel County Line
Mariposa Ranch
Drop down into a wooded valley
10: Morrison
8: Fluvial Sandstone
Continue to descend in relatively poor outcrops.
6: Debris flow in river
4: in Cutler. Well disguised in vegetation
0 Intersection with Rt. 145
Rt. 145 Westbound Mile Markers
Cross Creek, 16 miles to Telluride
Cutler on all sides
83.8 Placerville
83 Excellent Cutler r/c with thin dike
82.5 Blue Jay bar and café
81 Conglomerates!
Sawpit: fine grained redbeds
Nice scour-based sands well exposed in many r/c on east side of road
78: Climb up along Qal and shaly rich outcrops Could there be some Mancos in here? Junction with route to Dolores
3 miles to Telluride
Road log from Telluride Jct. to Dolores
68 miles to Dolores.
70: Black shales entrance to Telluride ski area.
All sorts of posh developments in this area, most are fairly well disguised.
Sunshine Mountain and Wilon Peaks view to southwest.
67: jagged ridge to SE
Alta Lakes Road
65: Black Shales, road falling in. Either Belden or Cretaceous shales
Fabulous flow massifs overhead on east of a tight corner with a sign for a post office. This appears to be a huge plug of igneous mat'l intruding shales.
Fine grained intrusive? in road-cuts
63.1 Old Butterfly rd.
Matterhorn Drive
61.4 Trout Lake cutoff to east.
59.5 Black shales at the Delores/San Miguel County line.
Crest of pass, low open area, tons of snow on March 30, 2000.
58.5 Pass by Sheep Mountain
57.5 Lizard Head spire to west
Drop down back into a pine wooded valley in the Cutler Fm.
55: Trough cross bedded fluvial sands.
53.8: Rt. 535 to Dunton is road to Chanterelles.
51-52 Great redbed o/c
49 Grey fluvial sands of the local Cutler
47.5 Cross the Dolres River and enter Rico
1892 Enterprise Bar and Grill on west is and awesome bldg.
46: Beaver ponds in lowlands of Dolores River.
43 Montezuma County line
42 Fine laminated fluvial sands and muds
39: Great red sandstone outcrop.
38.8 Roaring Fork Rd to east.
36-38 Many good outcrops of relatively fine grained redbeds.
36.2 Circle K Ranch
34: great trough cross beds
33.9: ALERT look at the color change from reds to greys here … is this a fault?
28 great fluvial sands
27: Beautiful sweep of Entrada Sandstone forms arch in front and sweeps around the west side of the valley!
26: Old ski area to east
24 Entrada
23.5 Cutoff to right
22.5 Eolian Entrada sandstone forms massive r/c on west. Exquisite o/c of toe sets of dunes (sure they aren't troughs?)
21: Water storage system in old gravel pits to east
17.5-18.5 Patch road-cuts in the Entrada. Clearly eoliams multimeter dune foresets.
17: Entrada dives below road level, we are in the Morrison.
16: Dakota forms sky line ahead.
14 In Morrison, outcrops are poor but it seem to be fluvial.
11.5 Enter Dolores 6936 feet. McPhee Reservoir Cutoff to west. Old Germany Restaurant
Junction 184, views of McPhee Reservoir to the right.
Sleeping Butte Mt hoves into sight and voila the Mesa Verde unfolds before you with Cortez at its feet.
Rt. 64 Eastbound Mile Markers
Mile 0 Dinosaur
Cross flats of Wasatch Formation, drop through Mesaverde Group, then drop through the Sego, Lloyd and Castlegate sandstones into the Mancos Shale valley, site of Rangely oil field. Many wells producing from Weber Sandstone are visible. See structure map of Rangely Field on p. 224, and cross section on p. 227 of RMAG 1986 book on New Interp of NW Colorado. Discovered in 1933, 20 acre spacing, Cum Prod April 1986 is 690 MMbo; OOIP is about 1.5 BBO, 424 producing wells. Largest oil field in Colorado. In summer 2006 I asked a bunch of kids in the Rangely Kum-and-Go if they knew of an oil field around here….they said there was something of that like in Parachute, they thought….
17 Enter Rangely
17.5 Cross White River
18 Black Cat mural
19.5 Junction. Rt. 139 to south.
20 Meeker is 56 miles
21 Airport, enter map USGS I-2400.
21-22 Very sharp based sandstone to north, this is the Castlegate.
23 Note small shingle off base of Castlegate!
23.8 Taylor Draw Dam. Castlegate sand intercepts the north edge of the dam.
24 Boat Ramp. Lloyd sand is well exposed across reservoir, it dips towards us and is present at lake level on the east end of the boat dock area.
25 Sego sand is across valley with prominent white cap and KMv above it; Lloyd is at reservoir level.
26 Jesus is Coming Ss. One of a series of elegant channels in the Mesaverde (locally known as the Williams Fork).
27-28 Fluvial belt in the Kmv.
27.5 Deserado Mine road.
30 near axis of Red Wash syncline.
44 Yellow Creek enters from south. Blair Mt is visible to south, comprised of Parachute Creek Mbr. of the Green River Fm.
53 Bluff of Tga1 member of the Green River Fm on north side of river.
54.8 Cross White River
56 Co Route 5 enters from south. This is a short cut? to Rifle.
57 Rio Blanco reservoir south of road; note scattered gas wells, also terrace well developed south of reservoir.
67 entering Powell Park; broad flat bottom lands with meandering White River.
68 Exposures N and NW of road, dramatic Green River Fm sandstones over blue mudstones of the Wasatch Fm.
71 Leaving map USGS I 2400, entering Craig 2 degree sheet.
71.5 Meeker's massacre site!
73 Rim Rock campground and northern edge of Grand Hogback; Kmv dipping steeply to west.
73.5 Junction with Rt.13 at mile 39; coal and clinker to north.
Rt. 13 Northbound
41-43 Meeker town.
43.2 Cutoff to Buford on Rt 8; 47 miles to Craig.
46 Iles Sandstone to west.
47 Iles at road level, enter into Kmv non-marine facies
49 Landslides abundant in this area.
52.1 Nine Mile Gap summit.
55.8 Coal mine.
57 coal and clinker.
58.3 Moffat County line.
61.2 Coal mine.
63 Iles Sandstone dipping to south, drop onto Mancos-floored valley. 26 miles to Craig.
64 Kennecot Coal Co. lodge or Hq to north.
67.2 Good overview spot to view south facing slope of Iles Mt. Prominent triplet of sands comes in from the west, over the course of the cliff exposures it seems that the lowest sand shales out... Light was crummy when viewed in March, 1998. These sands are probably the Trout Creek Sandstone (which is the top of the Iles Formation). See article by Siepman (p.157-164 of RMAG 1986 NW Colorado volume). Sipeman did a Ms thesis on this at C S Mines (T-2954) and published it as CSM Quarterly v. 80 no. 2, in 1985. Together with an article by Dennis Irwin (p.151-156 in same volume) this package can be taken up to the Fox Hills final regressive sandstone.
72.1 Yellowjacket Pass access road.
74 Lowest sand crosses road.
75.8 Hamilton
76-77 Iles at road level, entering into Kmv.
81 Coal mine with elaborate conveyor systems.
82 Power Plant coming into view to NE.
88 Craig
Test
41-43 Meeker town.
43.2 Cutoff to Buford on Rt 8; 47 miles to Craig.
46 Iles Ss to west.
47 Iles at road level, enter into Kmv non-marine facies
49 Landslides abundant in this area.
52.1 Nine Mile Gap summit.
55.8 Coal mine.
57 coal and clinker.
58.3 Moffat County line.
61.2 Coal mine.
63 Iles Ss dipping to south, drop onto Mancos-floored valley. 26 miles to Craig.
64 Kennecot Coal Co. lodge or Hq to north.
67.2 Good overview spot to view south facing slope of Iles Mt. Prominent triplet of sands comes in from the west, over the course of the cliff exposures it seems that the lowest sand shales out... Light was crummy when viewed in March, 1998. These sands are probably the Trout Creek Sandstone (which is the top of the Iles Formation). See article by Siepman (p.157-164 of RMAG 1986 NW Colorado volume). Sipeman did a Ms thesis on this at C S Mines (T-2954) and published it as CSM Quarterly v. 80 no. 2, in 1985. Together with an article by Dennis Irwin (p.151-156 in same volume) this package can be taken up to the Fox Hills final regressive sandstone.
72.1 Yellowjacket Pass access road.
74 Lowest sand crosses road.
75.8 Hamilton
76-77 Iles at road level, entering into Kmv.
81 Coal mine with elaborate conveyor systems.
82 Power Plant coming into view to NE.
88 Craig