Vallecito Conglomerate (CO*)
Early to Mesoproterozoic*
Named from exposures on both sides of Vallecito Creek, for about 1 mi north of south boundary of Needle Mountains 15-min quadrangle, La Plata Co., southwestern CO (Cross and Howe, 1905).
Southern Rocky Mountain region*
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 ([ ]).