Oahe Dam dam upstream is Garrison Dam, near Riverdale, North Dakota, and the next dam downstream is Big Bend Dam, near Fort Thompson, South Dakota. In September and October 1804, the Lewis and Clark Expedition passed through what is now Lake Oahe while exploring the Missouri River. Oahe Dam was authorized by the Flood Control Act of 1944, and construction by the United States Army Corps of Engineers began in 1948. The world’s first rock tunnel boring machine (TBM) was invented in 1952 by James S. Robbins for the Oahe Dam project, which marked the beginning of machines replacing human tunnelers. The
Boundary Dam Boundary Dam Boundary Dam is a concrete arch gravity-type hydroelectric dam on the Pend Oreille River, in the U.S. state of Washington. The dam is located in the northeast corner of Washington state, just south of the border with British Columbia, Canada. It is operated by Seattle City Light and makes up a significant portion of the City of Seattle's energy portfolio. On average, it provides upwards of 46% of the power generated by Seattle City Light. Boundary Powerhouse, located adjacent to the dam, is completely built inside of the rock that makes up the left abutment of the dam