Canyon Ferry Dam is a concrete gravity dam in a narrow valley of the Missouri River, United States, where the Big Belt Mountains and the Spokane Hills merge, approximately 68 miles (109 km) downstream from the confluence of the Gallatin, Madison, and Jefferson rivers, and about 20 miles (32 km) east of the city of Helena, Montana.

The dam and power plant were part of the Pick-Sloan Plan and approved by the Flood Control Act of 1944 which was signed on December 22.

[2] The 1949 structure replaced the original Canyon Ferry Dam 1.5 mi (2 km) upstream.

The original dam was constructed between 1896 and 1898 by the Helena Water and Electric Power Company.

The dam's spillway is located on its central portion and is controlled by four radial gates.