American Falls Reservoir, located at the town of American Falls, is the largest reservoir in the state at 56,000 acres when full. It has been one of the best fisheries in Idaho. Fishing is popular from shores and boats on the south end of the reservoir near the dam.
Boat ramps are available at several locations including the west side near the dam and Sportsmans Park at Aberdeen.
State Highway 39 rides the top of the reservoir's 9-story-high dam for over half a mile.