The Downey Historical Society is located at the Downey History Center in Apollo Park. For more than thirty years, the society's all-volunteer staff has been gathering and preserving records and artifacts from and about the southeastern part of Los Angeles County. The society's collection includes original photographs from 1870 to the present (copy negatives, duplicate prints, or 35-mm slides are…

The collection of the Duarte Historical Society and Friends of the Library focuses on the history of the City of Duarte and adjacent Bradbury. Its archive includes photographs, records, and other artifacts related to the settlers and families who developed Duarte, the local schools, and the local citrus industry..

Documents and photos relating to the history of the Crescenta Valley. The La Crescenta Valley Historical Society has a lot of materials on the New Years Flood of 1934, and the town of Montrose, plus some materials on the American portrait artist S. Seymour Thomas.

The Library has a large collection of manuscripts, printed books and periodicals, photographs, maps and ephemera relating to Los Angeles.