The District is an independent special district that was formed in December 1926 under the provision of Sections 19600-19734 of the California Education Code. It encompasses the approximate 8 square miles of Altadena, which is an unincorporated area of Los Angeles County.
The purpose of forming the special library district was to permit residents of unincorporated towns and villages to create for themselves an independent, locally controlled library district supported by property taxes and governed by a locally elected Board of Library Trustees responsive directly to the service needs of the community. The District contracted with the County of Los Angeles for library services until 1955, when it became independent, providing its own building, collection, personnel, and services for the District.
Currently, the District provides library services to a population of approximately 55,230 people according to the May, 2007 estimate for cities and counties from the Demographic Research Unit, State Department of Finance.
The Main Library located at 600 E. Mariposa St. was built in 1967. A park-like setting surrounds the 25,000 square foot building, which was designed by architect Boyd Georgi.The Branch Library, known as the Bob Lucas Memorial Branch Library in which the District Literacy Services are housed, was dedicated on the current site on Lincoln Avenue in 1957.