Rancho Santa Margarita is a city in Orange County, California, United States. One of Orange County’s youngest cities, Rancho Santa Margarita is a master planned community. The population was 47,853 at the 2010 census, up from 47,214 at the 2000 census. Although it is named for Rancho Santa Margarita y Las Flores, which was in San Diego County, the city limits fall within the borders of Rancho Mission Viejo. At 20 characters long, it is the longest city name in California.
The city seal has the brands of Rancho Mission Viejo and Rancho Santa Margarita and Las Flores on the border, with artwork containing Santiago Peak in the background. The tower in the foreground symbolizes the Rancho Santa Margarita Lake Tower.
Hughes Aircraft Company’s Microelectronic Systems Division moved to Rancho Santa Margarita in May 1988 from Irvine. In August 1992 the Hughes plant closed its facilities and moved the division to Carlsbad, California due to budget constraints in the aerospace industry.
Rolling Hills Estates had the longest city name in California with 19 letters until January 1, 2000, when the title was ceded to Rancho Santa Margarita (20 letters) upon the latter’s incorporation.
The City is a general law city and operates under the council-manager form of government. Rancho Santa Margarita is a contract city. Police services are provided through contract with the Orange County Sheriff. Fire Protection services are provided through the Orange County Fire Authority.
The majority of the neighborhoods in RSM are maintained by larger homeowners associations including SAMLARC, Dove Canyon, Rancho Cielo, Robinson Ranch, and Trabuco Highlands. Dove Canyon, Trabuco Highlands, Robinson Ranch and Rancho Cielo were all established before Rancho Santa Margarita was an incorporated community. East of Plano Trabuco Road is designated with a Trabuco Canyon code even though the area falls within the City of Rancho Santa Margarita boundary.