The Middle Fork of the Salmon River is a gem located in Idaho's Frank Church Wilderness. The largest wilderness area in the Lower 48. It is an awe inspiring place to get away from your phone, computer, and the rest of the "real world". This trip has been described as "life changing" by many of our clients. The wild, free flowing Middle Fork of the Salmon River is located in the largest wilderness in the lower 48. If you float the entire Middle Fork of the Salmon, your whitewater float trip will be six days and up to 100 miles long!