The Pima County Public Library serves the third largest land area of any library system in the United States. Our Libraries enrich lives and build our community through opportunities to learn, to know, to interact and to grow. With 27 public library branches serving Tucson and communities across Pima County including Arivaca, Green Valley, Sahuarita, South Tucson, Ajo, Marana, Oro Valley and Catalina, the Library provides a wide range of free services that contribute to the economic development of the community.