Joshua Tree National Park is located in southeastern California. It is immense, nearly 800,000 acres. Two deserts, two large ecosystems come together in the park. The park encompasses some of the most interesting geologic displays found in California’s deserts. Rugged mountains of twisted rock and exposed granite monoliths testify to the tremendous earth forces that shaped and formed this land. Arroyos, playas, alluvial fans, bajadas, pediments, desert varnish, granites, aplite, and gneiss interact to form a giant mosaic of immense beauty and complexity.