Formation of coffinite requires a uranium source, and may happen in reducing conditions, as evidenced by the associated presence of low-valence vanadium minerals.

It is the type locality for the copper vanadium minerals: bannermanite, blossite, fingerite, howardevansite, lyonsite, mcbirneyite, stoiberite and ziesite.

Samples of coffinite from the Colorado Plateau were found with black fine-grained low-valence vanadium minerals, uraninite and finely dispersed black organic material.

In the area of the type locality, the reducing environment caused by carbonaceous material in the Salt Wash and Brushy Basin members of the Morrison Formation precipitated uranium and vanadium minerals from solution.