The Colorado Desert region spans the low-lying southeastern corner of California, stretching from the Peninsular Ranges of San Diego and Riverside Counties in the west to the Colorado River in the east. It is a western extension of the Sonoran Desert region of southern Arizona and northern Mexico. The Colorado Desert region is almost uniformly dry, being in the strong rain shadow of the Peninsular Ranges and at the far western edge of the moist, humid summer air flows of the Arizona Monsoon. The vegetation of the Colorado Desert is considerably more lush and diverse than in the deserts to the north. This is in part a result of the lack of freezing temperatures, which allows a number of frost-sensitive species to thrive, including many cactus varieties and other succulents. In terms of vegetation composition, the connection with the Sonoran Desert is quite evident, although the large cactus of Arizona and Sonora are absent in California.
Molly's Castle, Goblin Valley