[1] It preserves fossils dating back to the late Pennsylvanian to early Permian.

[2] The formation is highly variable in lithology, consisting of interbedded black to reddish sandy, silty, or calcareous shale; brown to olive calcareous siltstone, brown to gray calcareous arkosic sandstone; gypsum; and gray argillaceous to silty limestone.

[1][2] It overlies the Lead Camp Limestone or Bishop Cap Formation and is overlain by the Hueco Group.

[2] The formation includes patch reefs and numerous fusulinids of Virgilian (Gzhelian) age.

Kottlowski and coinvestigators in 1956, who divided it into informal upper and lower members.