Oil and Gas Resources of South Dakota

The Williston Basin is an intracratonic, structural, and sedimentary feature that occupies portions of North Dakota, South Dakota, Montana, and Canada. It is known for its rich deposits of hydrocarbons. The oval-shaped depression is a geologic structural basin, but not a topographic depression. It extends approximately 475 miles north-south and 300 miles east-west. Sedimentation occurred in the Williston Basin from Cambrian (~ 543 million years ago) through Tertiary time (~2 million years ago) and is represented by a stratigraphic section approximately 16,000 feet thick at its deepest point in northwestern North Dakota.