Northwestern Division Fact Sheets

Lucky Peak Dam and Lucky Peak Reservoir

Press Operations — Fri, 10 Jul 2026 02:55:00 GMT

Lucky Peak Dam was authorized by the Flood Control Act of 1946. Construction of Lucky Peak Dam began in 1949. It was dedicated June 23, 1955. The dam is a rolled earthfill dam about 250 feet above the streambed and 1,700 feet long at the crest. Located just 15 minutes from Boise’s greater urban area, Lucky Peak Lake hosts about a million visits every year. It’s recreation areas offer a variety of recreation opportunities such as fishing, swimming, picnicking, boating, hiking and camping.

Lower Monumental Dam and Lake West

Press Operations — Thu, 09 Jul 2026 23:57:00 GMT

Lower Monumental Lock and Dam was the second of four dams constructed as part of the Lower Snake River Project, authorized in the Rivers and Harbors Act of 1945. Construction began in 1961, and three turbine units were operational in 1970. Three more units were operational in 1978. Lake Herbert G. West extends upstream of the dam for 28 miles to Little Goose Dam.

Lower Granite Dam and Lake Lower Granite

Press Operations — Thu, 09 Jul 2026 23:40:00 GMT

Lower Granite Lock and Dam was the fourth of four dams constructed as part of the Lower Snake River Project, authorized in the Rivers and Harbors Act of 1945. Construction began in 1965 and three turbine units were operational in 1975. Three more turbine units were installed and operational in 1979. Lake Lower Granite extends from the dam upstream for 40 miles to Lewiston, Idaho. The Corps constructed roughly 8 miles of levees around Lewiston, ID, to help protect lives and property from potentially destructive high water conditions.

Little Goose Dam and Lake Bryan

Press Operations — Thu, 09 Jul 2026 22:11:00 GMT

Little Goose Lock and Dam was the third of four dams constructed as part of the Lower Snake River Project, authorized in the Rivers and Harbors Act of 1945. Construction began in 1963, and three turbine units were operational in 1970. Three more turbine units were operational in 1978. Lake Bryan extends from the dam upstream for 37 miles to Lower Granite Dam.

Ice Harbor Dam and Lake Sacajawea

Press Operations — Thu, 09 Jul 2026 20:22:00 GMT

Ice Harbor Lock and Dam was the first of four dams constructed as part of the Lower Snake River Project, authorized in the Rivers and Harbors Act of 1945. Construction began in 1956, and three turbine units were operational in 1961. Three more turbine units were installed and operational in 1976. Lake Sacajawea extends 32 miles upstream to Lower Monumental Dam.

Dworshak Dam and Dworshak Reservoir

Press Operations — Thu, 09 Jul 2026 16:53:00 GMT

Originally authorized as Bruces Eddy Dam in the 1962 Flood Control Act, the name was changed to Dworshak Dam in 1963. Construction began in 1966, and the project started operating for flood control in 1972. The three turbine units began generating power in 1973. Dworshak Dam is the third tallest dam in the U.S. The reservoir extends upstream for roughly 54 miles into the Clearwater National Forest in the Bitterroot Mountains.

Libby Dam and Lake Koocanusa

Press Operations — Thu, 09 Jul 2026 16:08:00 GMT

Libby Dam was authorized by Congress in the 1950 Flood Control Act for hydropower and flood protection, and construction was completed in 1973. The dam is located on the Kootenai River, 17 miles upstream of Libby, Montana. The reservoir behind the dam, Lake Koocanusa, extends 90 miles upstream into British Columbia, Canada. Libby Dam is the fourth dam constructed under the Columbia River Treaty between the U.S. and Canada. The other three treaty projects are located in Canada.

Albeni Falls Dam and Lake Pend Oreille

Press Operations — Thu, 09 Jul 2026 15:04:00 GMT

Albeni Falls Dam was authorized by Congress in the 1950 Flood Control Act, and construction was completed in 1955. The dam is located at the site of natural waterfalls that impounded Lake Pend Oreille. On completion, the 90-foot-tall dam increased the storage of Lake Pend Oreille and reduced upstream and downstream flood risks. The dam is made up of a powerhouse with three generating turbine units and a spillway.

McNary Dam and Lake Wallula

Press Operations — Thu, 09 Jul 2026 14:02:00 GMT

McNary Lock and Dam was authorized by Congress for power and navigation in the 1945 Rivers and Harbors Act. Construction began in 1947, and all turbine units were operational in 1957. Lake Wallula extends upstream of the dam for 64 miles to Hanford and has over 242 miles of shoreline.

Chief Joseph Dam and Rufus Woods Lake

Press Operations — Thu, 09 Jul 2026 03:10:00 GMT

Chief Joseph Dam was originally authorized as Foster Creek Dam in the River and Harbor Act of 1946 for power and irrigation. The project was renamed Chief Joseph Dam in the River and Harbor Act of 1948. Construction began in 1949, and the first eight generating units were brought online in 1955. Eight more units were completed in 1958, then eleven more in 1979, to total 27 units. The construction of Chief Joseph Dam on the Columbia River created Rufus Woods Lake, which extends upstream for a distance of 51 miles.

John Day Dam and Lake Umatilla

Press Operations — Thu, 09 Jul 2026 01:15:00 GMT

John Day Lock and Dam was authorized by Congress for power, navigation, and flood control in the 1950 Flood Control Act and amended in 1957. The project was completed in 1971 near the city of Rufus, Oregon, 215 miles upstream of the Pacific Ocean. Lake Umatilla extends upstream of the dam for 110 miles to McNary Dam.

The Dalles Dam and Lake Celilo

Press Operations — Thu, 09 Jul 2026 00:08:00 GMT

The Dalles Lock and Dam was authorized by Congress for power and navigation in the 1950 Flood Control Act. The project was constructed between 1952 and 1957 near the city of The Dalles, Oregon, 192 miles upstream of the Pacific Ocean. Lake Celilo extends upstream of the dam for 24 miles to John Day Dam.

Bonneville Dam and Lake Bonneville

Press Operations — Tue, 07 Jul 2026 21:00:00 GMT

Bonneville Dam was authorized by Congress for power and navigation in the 1935 Rivers and Harbors Act. The first powerhouse, spillway, and navigation lock were completed in 1938, and the second powerhouse in 1981. The lock was expanded in 1993. Bonneville Lock and Dam was placed on the National Register of Historic Places in 1986 and declared a National Historic Landmark in 1987.