At 615,000 acres, Anza-Borrego Desert State Park is the largest state park in California and one of the largest desert protected areas in the west. Located in the eastern half of San Diego County, the park extends roughly 25 miles east to west and 50 miles north to south.
The Steele Burnand Anza-Borrego Desert Research Center, housed in a former country club, is located adjacent to the park in the town of Borrego Springs. An agreement with Anza-Borrego Desert State Park and the Anza-Borrego Foundation makes the park available to reserve users.
Anza-Borrego Desert State Park encompasses a wide variety of habitats. High elevation species such as white fir grow on several mountaintops. Sonoran Desert stalwarts such as ocotillo, palo verde, fishhook cacti, and creosote are found in hotter, lower elevation areas. A perennial stream, Coyote Creek, offers rare riparian habitat within this arid region. Thirty fan palm oases, piñon pine and juniper forests, and live oak woodlands. The eroded formations of the Borrego and Carrizo Badlands are found in the eastern portion of the park.
The 932 plant taxa found in the park include a number of species unusual in California, such as the elephant tree more typical of Baja California. Late winter and early spring bring spectacular wildflower blooms and throngs of visitors. Approximately 320 bird species such as greater roadrunners and golden eagles are on the park checklist. Reptiles and amphibians include over 60 different species such as chuckwallas, desert iguanas, and the red diamond rattlesnake. The 60 species of mammals range from kit foxes and mule deer to the majority of the endangered desert bighorn sheep remaining in California.
Petroglyphs, pictographs, and other archeological sites indicate that human habitation in the area began at gast 6,000 years BP. In the late eighteenth century, Spanish explorers encountered settlements of Kumeyaay, Cahuilla, and other native peoples in the area. The Southern Emigrant Trail and the Butterfield Overland Mail Route, which brought many nineteenth-century migrants to the West, pass through the park. The park's Begole Archeological Research Center houses maps and historical artifacts from all of these periods and is located near the reserve headquarters.
Reserve buildings will also house offices for the Anza Borrego Foundation, the nonprofit cooperating organization for Anza Borrego Desert State Park. The Foundation acquires land for conservation in and around the park, supports research in the region, and is a reserve partner in public service programs.