The Toroweap Formation outcrops as a thin layer of generally darker, interlayered slope- and cliff-forming strata lying between the brighter colored cliffs of the Kaibab Limestone above, and Coconino Sandstone below.

Later, Noble[7] in 1914 and Burnsife and Bassler[8] in 1922, subdivided Darton's Kaibab limestone into five subdivisions on the basis of their distinct and differing lithologies.

The basal layer of the Seligman Member is a red sandstone or siltstone composed of Coconino-like quartz grains scattered through finer-grained sediment.

The first facies is exposed in an area from the extreme western edge of its outcrop belt east to Toroweap Valley and southeast almost to Seligman, Arizona.

The second facies of the Brady Canyon Member is exposed in outcrops eastward past Seligman, Arizona to where it merges and terminates within the enclosing red beds.

A prominent feature found throughout the entire outcrop of the Woods Ranch Member is a fossil-bearing limestone, It occurs over a remarkably wide area without appreciable variation with a thickness of only 3 to 4 ft (0.91 to 1.22 m).

The western, open marine limestones of the Brady Canyon Member contain numerous fossils of bryozoans, brachiopods, bivalves, nautiloids, gastropods, scaphopods, ostracodes, crinoids, echinoids, and stromatolites.

[1][3] As of 2021, published information on the occurence and nature of invertebrate and vertebrate trace fossils found in the Toroweap Formation is lacking even though they should be present in the sedimentary strata comprising it.

[10][11] Marine transgressions, terrestrial wind-blown sand, coastal environments laid down the Kaibab, Toroweap, and Coconino formations.

[12][13] The Toroweap Formation represents a major marine transgression into the Grand canyon area during which red beds of the Seligman Member accumulated in supratidal, tidal, and terrestrial coastal plain environments.

The overlying limestones of the Brady Canyon Member accumulated in open and brackish-water environments during the maximum extent of the marine transgression.

The two members of the overlying Kiabab Limestone represent two additional major marine transgression into the Grand Canyon region.