Canyon Ferry Dam is a flood control reservoir located northeast of Helena on the Missouri River. Canyon Ferry Dam is located on the main stem of the Missouri River approximately 27 miles downstream from Townsend, Montana. The dam was constructed in a narrow constriction of the Missouri River Valley, where the Big Belt Mountains and the Spokane Hills merge, approximately 68 miles downstream from the confluence of the Gallatin, Madison, and Jefferson Rivers. The project authority is the Flood Control Act, Public Law 534, 78th Congress, 2nd Session, approved 22 December 1944.
The Missouri River has cut through the older Precambrian rocks forming a canyon well suited for a dam. The dam and power plant are located at the upper end of the rock-walled canyon, about 1-1/2 miles downstream from the previously existing Canyon Ferry Dam and power plant built by the Montana Power Company. The old Canyon Ferry Dam was built in 1896 and formed a reservoir known as Lake Sewell. The old 7,500-kilowatt power plant was completed in 1898. The old Canyon Ferry Dam and power plant were dismantled prior to the completion of the new Canyon Ferry Dam and power plant with the remnants having been inundated and Lake Sewell becoming part of the new reservoir. Canyon Ferry Dam lies at the head of the reservoir created by Hauser Dam, located 15-1/2 miles downstream. The backwater of Hauser Lake, when full, raises the tailwater at Canyon Ferry Dam.
The Visitor Center features hands-on displays and excellent interpretive information on Canyon Ferry's watchable wildlife. There are displays of the Lewis and Clark Expedition and the construction of Canyon Ferry Dam. The visitor center is currently closed. Information about Canyon Ferry can be obtained from the field office across the street from the visitor center.
There are many campgrounds and day-use areas surrounding the reservoir.