The Black River is a 114-mile-long (183 km) river in the White Mountains of the U.S. state of Arizona. It forms south of the town of Greer and west of the towns of Nutrioso and Alpine. The river flows southwest then northwest to meet the White River west of Fort Apache. The merged streams form the Salt River, a major tributary of the Gila River. Both the Salt and Gila rivers supply water to the Phoenix metro area as well as provides water for farmland and crops around the valley.

The Salt River is a river in Gila and Maricopa counties in Arizona, United States, that is the largest tributary of the Gila River. The river is about 200 miles (320 km) long. Its drainage basin covers about 13,700 square miles (35,000 km2). The longest of the Salt River's many tributaries is the 195-mile (314 km) Verde River. The Salt's headwaters tributaries, the Black River and East Fork, increase the river's total length to about 300 miles (480 km). The name Salt River comes from the river's course over large salt deposits shortly after the merging of the White and Black Rivers.