Abstract: Oil and Gas Potential on the Crow Indian Reservation, Montana

CAMPEN, ELIZABETH, B.

The Crow Indian Reservation is located at the northern end of the Powder River Basin in Montana, east of the Pryor and Bighorn mountain ranges. These Indian lands are composed of nearly ninety townships and encompass approximately 3,300 square miles. The geology of the reservation is potentially advantageous for hydrocarbons, yet exploratory efforts in this vast area have been sparse. Eliminating field wells, less than one well per township has been drilled.

The Crow Indian Reservation is a wild and beautiful nation and surface geology on the Reservation is fascinating. Outcrops encompass the whole geologic section from the Precambrian, which is exposed on the Bighorn River near the western edge of the Reservation to Tertiary Fort Union on the east. Structural features are numerous and are generally well defined. They consist of small domes, large anticlines, and numerous faults.

The obvious structures have been drilled resulting in the discovery of oil at Lodgegrass, Soap Creek, and Ash Creek fields, and gas at Hardin. Other more subtle structural possibilities exist and could definitely enhance stratigraphic traps. Interesting potential plays exist in the Parkman, Shannon, Muddy, Morrison, and Tensleep formations as well as some deeper Paleozoics; all of which have had good hydrocarbon shows.

General geologic, engineering, and seismic studies have been performed by independent consultants for the Crow Tribe. All are in agreement that serious hydrocarbon potential exists on the Crow Indian Reservation.

AAPG Search and Discovery Article #90946©1997 AAPG Rocky Mountain Section Meeting, Denver, Colorado