The Mendenhall River (Lingít: Woosh Ilʼóox̱ʼu Héen) is an Alaskan river north of Juneau in the Mendenhall Valley. The river begins at the Mendenhall Lake, at the base of the Mendenhall Glacier.
The Mendenhall is about six miles (9 kilometers) long, one mile (1.6 km) of which is whitewater. The most favorable months in which to raft on the river is May through September. The most active points along the whitewater section are Scott's Iatola (or Iatolla) Hola, Tourist Trap, and Pinball Alley. The whitewater ends near the Juneau International Airport.
Minor flood stage for the Mendenhall River is 12 feet (3.7 m), and a level of 14 feet (4.3 m) is more likely to cause extensive problems. If the Mendenhall is at minor flood stage, however, it is likely that areas such as Montana Creek, Jordan Creek, and the Mendenhall Lake are also experiencing flooding at that time.