Yermo is a town in the Mojave Desert in San Bernardino County, California. Its name is derived from one of the Spanish words for "wilderness". It is 13 miles east of Barstow on Interstate 15, just south of the Calico Mountains. Its population was an estimated 1,750 in 2009.
Founded in 1902 and originally named Otis, Yermo is situated at a division point of the Union Pacific Railroad line. A post office was established three years later with William J. Flavin serving as Yermo's first postmaster. The town later developed around serving motorists traveling the Arrowhead Trail (later U.S. Route 91), which ran through the community.
Today, Yermo is governed by an elected five-member board of directors comprising the Community Services District authorized by the County of San Bernardino. The board, which meets monthly, oversees the town's volunteer fire department, the Yermo/Calico VFD, as well as its street lighting, parks and water system. Yermo's ZIP Code is 92398, and it is in telephone area codes 442 and 760. Its USPS branch provides post office boxes to local residents and businesses; there is no letter-carrier service.
Yermo hosts the 1,859-acre (7.5 km2) storage and industrial annex of the Marine Corps Logistics Base Barstow.