This is the largest dam of its type east of the Mississippi River. Located in the town of Mt. Morris next to Letchworth State Park. Deep in the gorge of the Genesee River, 67 miles upstream of the city of Rochester, NY. The project was authorized by Congress in the Flood Control Act of 1944 and was constructed from 1948 to 1952 at a cost of $25 million. The dam provides flood protection for the lower Genesee Valley to Lake Ontario. The U.S. Army Corp. of Engineers provide tours of the dam.