[4] The rocks in the surrounding area are extremely diverse, with exposed (non-volcanic) layers ranging in age from Paleozoic to Holocene.

Folding and faulting of Lower Cretaceous layers occurred during the Laramide disturbance in the nearby East Potrillo Mountains.

This activity also seems to be associated with the intrusion of andesitic and quartz latite dikes in the East Potrillo range.

During the middle Tertiary, high angle faulting and uplifting occurred in the East Potrillo range and began to form intermontane basins.

In the middle to late Quaternary, alkali olivine basalt was extruded from fissures in the Fitzgerald, Robledo, and Aden faults.

Over half of the annual precipitation falls in the form of summer rains between June and September, although some snow can be expected in the winter.

Common mammals include mule deer (Odocoileus hemionus), coyotes (Canis latrans), black-tailed jackrabbit (Lepus californicus), desert cottontail (Sylvilagus auduboni), white-throated woodrat (Neotoma albigula), kangaroo rats (Dipodomys merriami and Dipodomys spectabilis), and cactus mouse (Peromyscus eremicus).

Common birds include golden eagles (Aquila chrysaetos), Swainson's hawk (Buteo swainsoni), northern harrier (Circus cyaneus), burrowing owl (Athene cunicularia), greater roadrunner (Geococcyx californianus), quail (Callipepla gambelii and Callipepla squamata), horned lark (Eremophila alpestris), western meadowlark (Sturnella neglecta), doves (Zenaida macroura and Zenaida asiatica), and black-throated sparrow (Amphispiza bilineata).

Archeological studies indicate that there have been at least three distinct periods of prehistoric human usage of the West Potrillos.

Beginning in about 6000 BCE, members of the Desert Archaic cultures moved into the area and remained until about 100 ACE.

The area is used for ranching, bird hunting, camping, hiking, and foot launched aviation (paragliding and hang gliding).

[7] In 1928, a fossilized ground sloth (Nothrotheriops shastensis) was found in a fumarole in Aden Crater.