Ryan Dam is a six-unit hydroelectric plant on the Missouri River, about 10 miles downstream from Great Falls, Mont. The units have a total generating capacity of 60 megawatts. (One megawatt can satisfy the average energy needs of 750 households.)

Built at the crest of the Great Falls of the Missouri, Ryan Dam began operation in 1915. It is 1,366 feet long and 61 feet high, and its reservoir is 7 miles long and has a storage capacity of 5,000 acre-feet. The dam is classified as a “run-of-river” project because it can generate electricity using the water that flows down the river, without the need to store additional water supplies.