No current usage.
(†Wyoming Formation or †Wyoming Group (CO) abandoned. Replaced with Lykins Formation, Lyons Sandstone, Ingleside Formation, and Fountain Formation. See Lykins, Lyons, Ingleside, and Fountain.)
Pennsylvanian to Triassic
Named for widespread development in Wyoming, but application of name in literature has been restricted to eastern CO .
Denver basin
Eagle basin
For more information, please contact Nancy Stamm, Geologic Names Committee Secretary.
Asterisk (*) indicates published by U.S. Geological Survey authors.
"No current usage" (†) implies that a name has been abandoned or has fallen into disuse. Former usage and, if known, replacement name given in parentheses ( ).
Slash (/) indicates name conflicts with nomenclatural guidelines (CSN, 1933; ACSN, 1961, 1970; NACSN, 1983, 2005, 2021). May be explained within brackets ([ ]).