The June L. Mazer Lesbian Collection, formerly the West Coast Lesbian Collections, was founded in Oakland, California, in 1981. Six years later it was moved to Los Angeles by Connexxus Women's Center/Centro de Mujeres, and it acquired its present name in 1987 after the death of June L. Mazer, a community activist and an invaluable supporter of the collection.

Collections include pamphlets and ephemera documenting the growth, industries, transportation, and social organizations of Los Angeles and greater southern California; photograph collections; thousands of books related to southern California; and numerous archival collections related to indiviuals, the citrus industry, and businesses in the Inland Empire.