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
Norris Dam State Park the Tennessee Valley Authority in the early 1930s. The Clinch River flows southwestward for from its source in southwestern Virginia to its mouth along the Tennessee River near Kingston. Norris Dam is located just over upstream from the mouth of the Clinch, near the Anderson-Campbell county line. Cove Creek, which flows down from its source in the Cumberland Mountains roughly to the northwest, empties into the Clinch approximately north of Norris Dam. The Powell River, which also rises in southwestern Virginia, empties into the Clinch approximately upstream from Norris Dam. Norris Lake spans a stretch of the Clinch from the