This is the middle formation of Veatch’s (1907) tripartite division of
the Wasatch Group. It is now found to be the youngest formation in
Fossil Basin. It is not exposed in Fossil Butte National Monument.
Oriel and Tracey (1970) have formally divided and named three members of
the Fowkes Formation: a lower Sillem Member, a middle Bulldog Hollow
Member, and an upper Gooseberry Member.