Because the Cozy Dell easily weathers to a clay-rich soil, it crops out infrequently and generally forms dense stands of chaparral in saddles between peaks and ridges of the more resistant Matilija and Coldwater formations.

He also named the formation after its type locality at Cozy Dell Canyon, which is located on the south side of Nordhoff Ridge, just north of Ojai in Ventura County.

Because the Cozy Dell is layered between the highly resistant Matilija and Coldwater sandstones, and turned up on end through most of its extent, it erodes to create passes and saddles between peaks and ridges of the adjacent units.

[7] However, some larger fossils have been found in a few localities in the Topatopa Mountains to the east in Ventura County, particularly in the upper Sespe Creek area near Ojai, which contains an unusual shallow-marine assemblage of molluscs, starfish and brittle stars, as well as plant imprints that indicate close proximity to an ancient shoreline.

[8] The Cozy Dell represents a time when the Eocene sea covering the California border land region reached its widest extent and maximum water depths.

[10][11] Although there is no onshore oil or gas production from the Cozy Dell, its organic content is high enough that some geologists believe it may be a potential source rock for petroleum found in other units.