The Oak Park Branch Library is a public library that serves nearly 1.4 million residents in the city of San Diego, on the Pacific coast of California. It is an affiliate branch of the City of San Diego Public Library. The Oak Park Library started as a popular bookmobile stop in the 1950s. In 1969, a 5,200-square-foot building was opened in response to the escalating demand for library services in the community. Today, Oak Park Library contributes to the city library system's entire resources, which include almost 5 million books and serial volumes, more than 75,000 e-books, more than 200,000 audio files, and nearly 300,000 video files. In addition, the library system catered to more than 680,000 registered borrowers, approximately 6.9 million items circulated annually, and more than 6.1 million visitors.