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 long. Its drainage basin covers about 13,700 square miles. The longest of the Salt River's many tributaries is the 195-mile Verde River. The Salt's headwaters tributaries, the Black River and East Fork, increase the river's total length to about 300 miles. From Wikipedia