The report area includes approximately 200,000 square miles in the southern part of the Williston basin of North Dakota, South Dakota, and eastern Mon- tana and in central Montana and north-central Wyoming. Devonian ...

The Minot area is in the north-central part of North Dakota and includes part of the Souris River valley. The region is covered by glacial drift of late Wisconsin age except in small areas where the Fort Union Formation ...

The Souris River area comprises about 5,500 square miles in north-central North Dakota. It is bounded roughly by the east loop of the Souris River on the east, by the Max moraine on the southwest, and by the International ...