The dam was completed in 1910 by Magic Reservoir Hydroelectric, Inc. for irrigation, flood control and hydroelectric generation, and stores up to 195,000 acre-feet (0.241 km3) of water in Magic Reservoir, which lies in both Blaine County and adjacent southeastern Camas County.
[2] Magic Dam also supports a power station with three turbines totaling a capacity of 9,000 kW.
[1] Two auxiliary dikes keep the reservoir from overflowing during high elevations, while a concrete emergency spillway located west of the dam helps to pass floodwaters.
At full water levels, Magic Reservoir covers up to 3,740 acres (1,510 ha), extending 6 miles (9.7 km) up the Big Wood River and 2.5 miles (4.0 km) up a tributary, Camas Creek.
The dam and reservoir control runoff from a catchment area of 1,600 sq mi (4,100 km2).