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..

The Special Collections holdings reflect the diverse communities of the Claremont Colleges and the local area and region. Among the collections especially pertinent to Los Angeles and Southern California are the following: