Numerous peaks in the Riverside Mountains give this small range a rough, craggy appearance.

[3] The Riverside Mountains are one of several ranges that constitute the Maria Fold and Thrust Belt (MFTB).

The Maria Fold and Thrust Belt underwent generally thick-skinned (involving basement rocks) north–south-trending crustal shortening in the Cretaceous.

The structures of the MFTB are exposed by to later generally east–west-trending large-scale crustal extension in the Miocene, through what is known to geologists as the Colorado River Extensional Corridor.

The Riverside Mountains contain rocks from both the lower and upper plates of a large detachment fault and metamorphic core complex system as a result of the Miocene-age extension.