The lower member is 60 feet (18 m) of coarse conglomerate consisting mostly of fragments of volcanic rock.

The upper member is 180 feet (55 m) of calcareous grayish-pink sandstone, poorly sorted and very fine- to coarse-grained.

It is relatively resistant to erosion and so forms cliffs and shelves[3] and caps mesas in the area.

[5] The volcanic rock fragments making up the formation are thought to come from the Oligocene Mogollon-Datil volcanic field and the formation itself is thought to be Miocene in age.

[7] The beds making up the unit were originally included in the Bidahochi Formation by Charles Repenning and James Irwin in 1954, along with all other Tertiary beds of the Zuni Plateau.