Southern Arizona

Southern Arizona is a region of the United States comprising the southernmost portion of the State of Arizona. It sometimes goes by the name Gadsden or Baja Arizona, which means "Lower Arizona" in Spanish.

Although Southern Arizona's boundaries are not well-defined, it is generally considered to include all areas south of the Gila River but sometimes only Cochise County, Pima County and Santa Cruz County, anchored by the city of Tucson. Other cities and large towns in Southern Arizona include Ajo, Casa Grande, Gila Bend, Oro Valley, Sierra Vista, Yuma, and the border cities of Nogales and Douglas

Furthermore, the populated areas of Southern Arizona include the major U.S. Army post of Fort Huachuca and Davis-Monthan Air Force Base of the U.S. Air Force.

The most major scientific site of Southern Arizona is the set of several astronomical observatories of the Kitt Peak National Observatory, a reasonable distance west-southwest of Tucson.

Southern Arizona is the location of several large National Monuments protecting the scenery, wildlife, and archaeological sites of Southern Arizona, and the Saguaro National Park, which stands on two large sections of land, one west of the Tucson metropolitan area and the other one east of Tucson.

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