The Barstow Field region covers an area from the northern boundary of Joshua Tree National Park to the southern boundary of Fort Irwin Military Reservation and from the eastern boundary of San Bernardino National Forest to north of Death Valley Junction, California, as far as the California/Nevada state line.

The desert within this area is vast, about three million acres, and has many unique features. Elevations vary from near sea level, north of Baker, California, to over 6,000 feet, in the Ord Mountains south of Barstow. There are many scenic locations with rough mountains, dry lake beds, and winding canyons. Plants found here include various cactus species and the Joshua Tree, the symbol of the Mojave Desert.