Yuma County was one of the original four counties designated by the First Territorial Legislature. Until 1983, when voters decided to split it into La Paz County in the north and a new Yuma County in the south; it maintained its original boundaries.  Yuma County encompasses approximately 5,500 square miles in the southwest quadrant of Arizona - bordered by both California and Mexico.  Much of Yuma County is desert land accented by rugged mountains.  The valley regions, however, contain an abundance of arable land, which is irrigated with Colorado River water. Agriculture, tourism, military and government are the county’s principal industries. During the winter months, the population grows considerably with part-time residents. All of Yuma County is an Enterprise Zone. 

Just under 200,000 people have made Yuma County their home - and love its comfortable, affordable lifestyle. The region's economy thrives on a $1.3 billion high-tech agribusiness industry, two prominent defense facilities, a progressive regional medical facility, expansive retail and hospitality and a growing manufacturing sector.