The Middle Fork of the Salmon River is a 104-mile-long river in central Idaho in the northwestern United States. The Middle Fork lies in the middle of the Frank Church-River of No Return Wilderness, part of the largest road less area left in the lower 48 states. The Middle Fork is a tributary of the Salmon River, which is the main tributary of the Snake River, which in turn is the main tributary of the Columbia River. The Middle Fork is one hundred miles of whitewater. The Middle Fork has three hundred rapids for rafters to enjoy. Protected by the Wild and Scenic Rivers Act in 1968, it remains one of the most beautifully unspoiled whitewater rafting rivers in the world.