[3] In 1917 a 'substitute' type locality was located by Gregory in the wall of the Little Colorado Canyon, about 5 miles below Tanner Crossing in Coconino County, Arizona.

[4] While in the Great Basin, Bassler and Reeside characterized and named the Rock Canyon Conglomerate, Virgin Limestone, and Shnabkaib Shale members in 1921.

The Tenderfoot, Ali Baba, Sewemup, and Pariott Members were named in the Piceance and Uinta Basins by Shoemaker and Newman in 1959.

Blakey named the Black Dragon, Torrey, and Moody Canyon members in the Paradox Basin and Plateau Sedimentary Province in 1974.

The Anton Chico Member was assigned in the Palo Duro Basin and areal limits set by Lucas and Hunt in 1989.

In eastern Nevada and northwestern Utah, it thickens dramatically, then transitions to the Woodside, Thaynes, and Mahogany formations.

Thickness varies from a feather edge against the Uncompahgre highlands to the east to over 600 metres (2,000 ft) in southwestern Utah.

[17] In different regions, by ascending stratigraphic order, the members are: Paradox Basin:[18][19] Canyonlands and Glen Canyon area:[18] San Juan Basin and Tucumcari:[12][20][21] Other members listed in alphabetical order, with asterisks (*) indicating usage by the U.S. Geological Survey and other usages by state geological surveys:[22] Found in these geologic locations:[22] Found within these parks (incomplete list): Numerous fossils of bivalves were found in the Olenekian Virgin Limestone Member of the Moenkopi Formation, in south-western Utah.

The discovery of 27 species from 18 genera of two subclasses in these sites in 2013 cast doubt on previous claims that the bivalve fauna only recovered in the Middle Triassic after the end-Permian mass extinction.