The Payette River () is an river in southwestern Idaho and is a major tributary of the Snake River. Its headwaters originate in the Sawtooth and Salmon River Mountains at elevations over . Drainage in the watershed flows primarily from east to west, with the cumulative stream length to the head of the North Fork Payette River being , while to the head of the South Fork the cumulative length is nearly . The combined Payette River flows into an agricultural valley and empties into the Snake River near the city of Payette at an elevation of . The Payette River's drainage basin comprises about . It is a physiographic section of the Columbia Plateau province, which in turn is part of the larger Intermontane Plateaus physiographic division. The South Fork of the Payette has its headwaters in the Sawtooth Wilderness, which is part of the Sawtooth National Recreation Area. Geography The principal tributaries of the Payette River are the North and South forks. The North Fork drains about , beginning north of McCall and flowing into Payette Lake. The North Fork exits at the southwest end of Payette Lake at and flows south in the "Long Valley" of Valley County toward Cascade. It then flows into the Cascade Reservoir, then continues south, accompanied by Highway 55. The South Fork Payette River drains about , originating on the west side of the Sawtooth Wilderness beneath the Mount Payette. It flows past Grandjean and down to Lowman, along Highway 21. The shorter Middle Fork Payette River parallels the lower North Fork to the east, flowing south and joining the South Fork just southwest of Crouch. Further east, the Deadwood River parallels the Middle Fork and empties into the South Fork just west of Lowman. The main stem of the Payette River is shown on USGS topographic maps as beginning at the confluence of the South and Middle forks. The North Fork joins the Payette at the village of Banks, at an elevation of . The main stem flows south from Banks for to Horseshoe Bend, then west into Black Canyon Reservoir. Below the reservoir's dam, the river flows past Emmett and Payette, then empties into the Snake River at the Oregon border. The Payette River has an average annual discharge into the Snake River of of water. History The river's watershed was originally settled by the Shoshone, Nez Perce, Paiute and