[2] The formation is 170 meters (560 ft) thick in the Peace River and Smoky River area, and thickens up to 900 meters (3,000 ft)[3] in the foothills of the Northern Rocky Mountains in British Columbia.

[3] The Kaskapau Formation is equivalent to the Colorado Group shale in central Alberta.

The Kaskapau Formation is represented mostly by dark grey shale, with sandstone tongues and lentils at the base (Doe Creek Member, Pouce Coupe Member).

Thin volcanic ash layers may occur in the British Columbia foothills.

Oyster fossils are encountered at the base of the formation, and Inoceramus fragments (such as I. labiatus) are found throughout the entire stack.