Ogallala Group (CO,KS,NE,SD,TX,WY)
Ogallala Formation (CO*,KS*,NE*,NM*,OK*,SD*,TX*,WY*)
GROUP STATUS (alphabetical): Ash Hollow Formation (CO,NE,SD,WY), Bridwell Formation (TX), Couch Formation (TX), Kimball Formation (CO,NE), Sidney Formation (CO,NE) or Sidney Gravel (CO,NE), Snake Creek Formation (NE,WY), Thin Elk Formation (SD), Valentine Formation (NE,SD).
FORMATION STATUS (alphabetical): Ash Hollow Member (KS), Bridwell Member (TX), Couch Member (TX), Kimball Member (KS), Valentine Member (KS), Woodhouse Clay [Member] (KS).
Not designated. Named from development in western part of Nebraska, around Lodgepole Creek and area between Platte River and Kansas line west of 99th Meridian (Darton, 1899).
Elias (1942) states type locality is on north side of South Platte Valley, 2 to 2.5 mi east and northeast of Ogallala, Keith Co., southwestern KS (also type locality for Feldt Ranch Beds of Ash Hollow Formation).
Wind River basin*
Powder River basin*
Sierra Grande uplift*
Palo Duro basin*
For more information, please contact Nancy Stamm, Geologic Names Committee Secretary.
Asterisk (*) indicates usage by the U.S. Geological Survey. Other usages by state geological surveys.
"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 does not conform with nomenclatural guidelines (CSN, 1933; ACSN, 1961, 1970; NACSN, 1983, 2005). This may be explained within brackets ([ ]).