[1][2] At the type section near Tucumcari, the formation consists of alternating beds of light gray sandstone and brownish red siltstone.

Bed thicknesses vary from 2–10 feet (0.61–3.05 m), distinguishing the unit from the massive sandstone of the underlying Exeter Sandstone and poorly bedded sediments of the overlying Morrison Formation.

[3] Further north, in the valley of the Dry Cimarron, the facies changes to dark mudstone with no cycles and more abundant gypsum.

[2] The beds making up the unit were originally assigned to the Wanakah Formation, but were renamed by Griggs and Read in 1959 for exposures at Carpenter's Point, 13 miles (21 km) northwest of Tucumcari.

[6] In 1987, Conrad et al. correlated the "brown-silt member" assigned by Baldwin and Muehlberger to the Morrison Formation in the valley of the Dry Cimarron[7] to the Bell Ranch Formation.