The Mara Salvatrucha gang originated in Los Angeles, set up in the 1980s by Salvadoran immigrants in the city's Pico-Union neighborhood who immigrated to the United States after the Central American civil wars of the 1980s.
Definition. The Sierra Club is the oldest grassroots environmental organization in the United States. The organization was founded in 1872 by a San Francisco group of professors, businessmen, and other professionals led by John Muir (Cohen 1985, 10).
Meaning of Sierra. Irish name. In Irish, the name Sierra means-Dark. Feminine of Ciaran.. Other origins for the name Sierra include-Irish, Spanish.The name Sierra is most often used as a girl name or female name.