Usage:
Kootenai Formation (ID*,MT*)
(Kootenai is U.S. Board on Geographic Names spelling. Spelled Kootenay or Kootanie in Alberta and British Columbia, Canada.)
Subunits:
(alphabetical): Cut Bank Sandstone Member (MT*), Moulton Member (MT*), Pryor Conglomerate Member (ID*,MT*), Sunburst Sandstone Member (MT*).
Geologic age:
Early Cretaceous (Aptian to Albian?)*
Type section, locality, area and/or origin of name: (See Canadian Lexicon)
Named from tribe of Indians who hunted over that part of Rocky Mountains in southern Alberta and British Columbia, Canada (Dawson[?], 1885; Dawson, 1886).
Reference section: [roadcut about 6.5 mi southeast of Bozeman, south side of Northern Pacific RR and Rocky Creek], in NE/4 sec. 25, T. 2 S., R. 6 E., [in vicinity of Lat. 45 deg. 38 min. 25 sec. N., Long. 110 deg. 55 min. 13 sec. W., Kelly Creek 7.5-min quadrangle, Gallatin National Forest], Gallatin Co., MT (Roberts, 1972).
AAPG geologic province:
Bighorn basin*
Yellowstone province*
Snake River basin*
Montana folded belt*
Sweetgrass arch*
Central Montana uplift*
Powder 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 ([ ]).