Colorado Group

Consists of Niobrara Formation (Kn) and either Benton Shale or Carlile, Greenhorn, and Graneros Fms (Kcg)
State Colorado
Name Colorado Group
Geologic age Cretaceous
Lithologic constituents
Major
Sedimentary > Clastic > Mudstone > Shale
Sedimentary > Carbonate > Limestone
References

Tweto, Ogden, 1979, Geologic Map of Colorado: U.S. Geological Survey Special Geologic Map, scale 1:500,000.

NGMDB product
Counties Boulder - Douglas - Eagle - Fremont - Grand - Jackson - Jefferson - Larimer - Park - Summit