Anza-Borrego Desert State Park Anza-Borrego Desert State Park is tucked into the southeastern corner of California. Running about 25 miles east-to-west and 50 miles north-to-south, it is California’s largest state park encompassing more than 600,000 acres. It is framed by, and includes many rugged mountain ranges: the Bucksnorts and the Santa Rosas on the north, the Jacumba Mountains on the South and the Vallecito and Pinyon Mountains on the west. To the east, the Borrego Mountains taper into the Carrizo Badlands before falling away into the Salton Trough. There are more than 500 miles of roads in the park . There are routes up rocky hills, through deep sand, along scenic streams and down steep hills. You and your family can enjoy Auto touring, biking, hiking, climbing, horseback riding and wildlife viewing.