No current usage.
(Rocks of †Rico Formation (AZ*,CO*,NM*,UT*) reallocated to lower part of Cutler Group and Honaker Trail Formation of Hermosa Group. See Cutler and Honaker Trail.)
Late Pennsylvanian to early Permian*
Named from exposures in Rico Mountains, [Dolores Co.], southwestern CO (US geologic names lexicons, USGS Bull. 896, 1200).
Paradox basin*
San Juan basin*
San Juan Mountains province*
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 ([ ]).