Named a member of Fox Hills Formation. Was designated "Bed Q" (Meek, Hayden, 1857) and Colgate lithofacies by recent workers. Exposed as caps on buttes. Type section: N1/2 secs 8 and 9, T132N, R76W, Emmons Co, ND. Reference section: 1) NE1/4 NW1/4 sec 28, T130N, R78W, Emmons Co; 2) NW1/4 SE1/4 sec 23, T22N, R28E, Corson Co, SD. These sections are in Williston basin. Areal extent map (includes Sioux Co, ND). Columnar sections. Thickness ranges from 0.2 to 7 m; average 2 m; no complete section; neither contact well exposed. May rest on Bullhead lithofacies of Fox Hills. Probably overlain by Hell Creek Formation. Most common sandstone (subgraywacke to feldspathic arenite) lithologies (ascending) are gray to brown: 1) semi-indurated, pelleted, friable, loosely packed, permeable, moderately sorted, subangular, fine grained; 2) indurated, brittle, massive, moderately packed, moderately sorted, moderately permeable, subangular to subround, fine to very fine grained; 3) indurated, brittle, massive, moderately packed, angular to subangular, fine to very fine grained; 4) indurated, massive, loosely packed, poorly sorted, angular, very fine grained, silty; all samples bioturbated; have volcanic glass shards. Ripple and mud cracks rare. Faunal remains, burrows, rushes, root tubes, wood chips. Channel sand deposit along a wide, shallow, south-flowing estuarine river. Late Cretaceous, Maestrichtian age.

Source: GNU records (USGS DDS-6; Denver GNULEX).