Usage:
No current usage?
(†Sacajawea Formation (MT,SD,WY) considered abandoned? Uncertain if used by the MT, SD, and WY Geol. Surveys. Not used by the USGS.)
Geologic age:
Mississippian
Type section, locality, area and/or origin of name:
Type section: in SE/4 NW/4 NE/4 sec. 11, T. 2 N., R. 4 W., along hogbacks in middle of valley above Bull Lake, Wind River Mountains, Freemont Co., west-central WY. Named from Mount Sacajawea at head of Bull Lake Creek. A store and inn of that name are on Yellowstone Park Highway near mout of Bull Lake Creek. Word is Shoshone name of Bird Woman, guide of the Lewis and Clark expedition (Branson, 1937; see also Strickland, 1957).
AAPG geologic province:
Chadron arch
Denver basin
Powder River basin
Williston basin
Wind River 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 ([ ]).