Leon, now a ghost town, was a gold mining town in northern San Diego County from the 1880s, named for the Leon Mine that lay on a hill to the northwest of the town. Leon became part of southwestern Riverside County in 1893. Leon had its own post office from May 4, 1888 until July 31, 1911 when its post office was moved to Perris, California.
- U.S. Geological Survey Geographic Names Information System: Leon Mine at
- Frickstad, Walter N., A Century of California Post Offices 1848–1954, Philatelic Research Society, Oakland, CA. 1955, pp. 126–135.
- Perry–Castañeda Library Map Collection, California Topographic Maps, Elsinore 1898 1:125,000 (3.7MB)
- Leon, California, USGS Map Name: Winchester, CA Map Center: