The Antelope Valley is located in the westernmost part of the Mojave Desert, and is approximately 3,000 square miles in size. On the northwest, the Valley is separated from the San Joaquin Valley by the Tehachapi Mountains. On the south and southwest, it is separated by the San Gabriel Mountains. The north and east boundaries of the Antelope Valley are distinguished by isolated buttes.

Antelope Valley is a closed basin; that is, a basin which has no outlet for its surface streams. All rain water either sinks into the ground or collects in the lower part of the Valley. There are twelve creeks leading into the Valley from the south, which carry water in wet seasons. The names of these creeks are: Amargosa, Little Rock, Pallett, Sand, Big Rock, Bob's Gap, Deadman, Boulder, La Montaine, Muscal, Bone Yard and Sheep Creeks. At one period of its existence, data indicates that the Valley was covered by a large fresh­water lake.

The famous San Andreas Fault runs along the whole southern slope of the Antelope Valley. It forms a series of long, narrow, enclosed basins. One of the best places to view the fault is on the Antelope Valley Freeway, just north of Avenue S.