Rancho Mirage is a city in Riverside County, California, United States. The city is a low-density desert-resort community with resorts, golf courseā¦Rancho Mirage is a city in Riverside County, California, United States. The city is a low-density desert-resort community with resorts, golf courses, and country clubs within the Colorado Desert section of the Sonoran Desert. Nestled along the foothills of the Santa Rosa Mountains in the south, it is located several minutes east of Palm Springs. The city is adjacent to Cathedral City, Palm Desert, and unincorporated Thousand Palms. The population was 16,999 at the 2020 census, down from 17,218 at the 2010 census, though the seasonal population can exceed 20,000. Incorporated in 1973, Rancho Mirage is one of the nine cities of the Coachella Valley.