The Colorado Desert is a subdivision of the larger Sonoran Desert encompassing approximately 7 million acres.  The desert encompasses Imperial County and includes parts of San Diego County, Riverside County, and a small part of San Bernardino County. Most of the Colorado Desert lies at a relatively low elevation, below 1,000 feet, with the lowest point of the desert floor at 275 feet below sea level, at the Salton Sea. Although the highest peaks of the Peninsular Ranges reach elevations of nearly 10,000 feet, most of the region’s mountains do not exceed 3,000 feet.