Rancho Mirage is a resort city in Riverside County, California, United States. The population was 17,218 at the 2010 census, up from 13,249 at the 2000 census, but the seasonal (part-time) population can exceed 20,000. In between Cathedral City and Palm Desert, it is one of the nine cities of the Coachella Valley (Palm Springs area). Rancho Mirage was incorporated in 1973 from a merger of Mirage Cove with five unincorporated areas known as the "Cove communities" (Desert, Magnesia, Palmas, Tamarisk and Thunderbird), and had 3,000 permanent residents at the time.