Sandstone and siltstone; in Piceance basin. Formerly Evacuation Creek Member of Green River Fm
In Moffat and Rio Blanco Counties, sandstone, shale, and coal beds above Sego Sandstone. Along Grand Hogback south of Colorado River, sandstone and shale above coal-bearing sequence
In northwest and west-central: Intertongues complexly with units of overlying Mesaverde Group or Fm; lower part consists of a calcareous Niobrara equivalent and Frontier Sandstone and Mowry Shale Members; in areas where the Frontier and Mowry Members (Kmfm), or these and the Dakota Sandstone (Kfd) are distinguished, map unit (Km) consists of shale above Frontier Member. In Southwest: Lower part contains Juana Lopez Member (Kmj)
Shale, sandstone, marlstone, and limestone in Anvil Points, Garden Gulch, and Douglas Creek Members; in Piceance basin
Claystone, shale, and sandstone
Parachute Creek Member--Oil shale, marlstone, and siltstone; in Piceance basin
Sandstone, shale, and major coal beds
Weber Sandstone and Maroon Fm
Arkosic sandstone, conglomerate, shale, and limestone. Includes Madera Fm and Sharpsdale Fm of Chronic (1958) in Sangre de Cristo Range and Gothic Fm of Langenheim (1952) in Elk Mountains. Other units of Middle Pennsylvanian age.
Includes Piney Creek Alluvium and younger deposits
Locally includes talus, rock-glacier, and thick colluvial deposits
Includes basalts of Hinsdale Fm in San Juan Mountains - Servilleta Fm in San Luis Valley and many other occurrences
Sandstone and shale. Trout Creek Sandstone Member at top; coal beds in upper half
Sandstone and siltstone; west of Park Range
Claystone, mudstone, sandstone, and conglomerate
Sego Sandstone, Buck Tongue of Mancos Shale, and Castlegate Sandstone
Red siltstone and sandstone
Locally includes, at base, Burro Canyon Fm (shale and sandstone) or, in western Moffat County, Cedar Mountain Fm (conglomerate and shale)
Curtis is absent along Grand Hogback
Shale and sandstone
Shale, sandstone, and local coal beds
Frontier Sandstone and Mowry Shale Members and intervening shale zone
Gypsum, siltstone, and shale; salt present in deep borings. Intertongues with Minturn and Lower Maroon Fms. Diapiric structure in many places
Includes some unclassified glacial deposits
Includes Broadway and Louviers Alluviums
Dakota Sandstone or Group
Shale, limestone, and sandstone. Includes Kerber Fm in south-central
Parting Fm: quartzite and shale.
Dotsero Fm: Dolomite, in White River plateau only. Peerless Fm: sandstone and dolomite.
Includes dune sand and silt and Peoria Loess
Leadville Limestone, Williams Canyon Limestone , Manitou Limestone, and Sawatch Quartzite
Eastern Uinta Basin Members of the Green River Formation (Evacuation Creek Mbr, Parachute Creek Mbr (oil shale), Garden Gulch Mbr, and Douglas Creek Mbr.).
Mainly Lower Cretaceous, Jurassic, and Triassic Fms
Includes Boulder Creek -M.Y. AGE GROUP (AGE 1650-1730 M.Y.)--Includes Boulder Creek, Cross Creek, Denny Creek, Kroenke, Browns Pass, Powderhorn, Pitts Meadow, Bakers Bridge, and Tenmile Granites, Quartz Monzonites, or Granodiorites; also, unnamed granitic rocks
In dikes and plugs
Northwest: includes Duchesne River Fm (sandstone and shale; includes some rocks of Eocene age) and Bishop Conglomerate near Utah border. South-central: includes Florissant Lake Beds (tuffaceous shale and tuff) and Antero Fm (limestone tuff, tuffaceous sandstone, and conglomerate). Southwest: includes Creede Fm (tuffaceous siltstone, sandstone, conglomerate) and gravels interbedded with volcanic rocks northeast and southeast of Gunnison
Wasatch/Colton Formations and Flagstaff Limestone.
Duchesne River Fm, Uinta Formation (south of Uinta Mtns.) and Bridger Formation (north of Uinta Mtns.).
Older alluvial deposits
Alluvium and colluvium
Minturn and Belden Fms