No current usage.
(†Hoadley Formation (MT) replaced with Snowslip, Shepard, and Mount Shields Formations. See Snowslip, Shepard, and Mount Shields.)
Mesoproterozoic
Not designated. Named from Hoadley Reef, Saypo quadrangle, Teton Co., MT (Deiss, 1943).
Northern 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 ([ ]).