Oahe Dam the Rocky Mountains forced the dam to open the release gates (not the spillway), releasing in June with another through the power plant totaling . The previous release record was in 1997. Oahe Dam The Oahe Dam is a large earthen dam on the Missouri River, just north of Pierre, South Dakota, United States. The dam creates Lake Oahe, the fourth largest man-made reservoir in the United States. The reservoir stretches up the course of the Missouri to Bismarck, North Dakota. The dam's power plant provides electricity for much of the north-central United States. It is named for the Oahe
Rock Island Dam Rock Island Dam Rock Island Dam is a hydroelectric dam on the Columbia River in the U.S. state of Washington. Chelan County Public Utility District's "Rock Island Dam and Hydro Project" was the first dam to span the Columbia, having been built from 1929 to 1933. It is located near the geographical center of Washington, about 12 miles (19 km) downstream from the city of Wenatchee. By river, the dam is 235 miles (378 km) south of the Canada–US border and 453 miles (729 km) above the mouth of the river at Astoria, Oregon. The dam's reservoir is called Rock