Pima County is a sprawling region in south-central Arizona, and with a population of 1,043,433 (2020 census), it ranks as the state's second-most populous county. Centered around its seat, Tucson, the county is named after the indigenous Pima (Akimel O'odham) people and encompasses the entire Tucson metropolitan area, the third-largest in the Southwest. Created in 1864 from land acquired in the Gadsden Purchase (1853), it was one of Arizona's four original counties but later ceded territory to form Cochise, Graham, and Santa Cruz counties. The county is rich in cultural and natural landmarks, including parts of the Tohono O'odham Nation, Saguaro National Park, and Organ Pipe Cactus National Monument, while its population is heavily concentrated in Tucson and its suburbs, leaving the western expanse sparsely populated. Demographically, the county is notably diverse, with a 35.7% Hispanic or Latino population and a median age of 41.2, and it is recognized for its forward-thinking Sonoran Desert Conservation Plan.