Lake Shannon

Lake Shannon
Lake Shannon looking downstream during the floods of 2003, with the Lower Baker Dam in the distance
Lake Shannon Show map of Washington (state) Lake Shannon Show map of the United States
Location	North of Concrete, Skagit County, Washington, US
Coordinates	48°32′51″N 121°44′28″W / 48.54750°N 121.74111°W / 48.54750; -121.74111
Type	Reservoir
Primary inflows	Baker River, Thunder Creek, Sulphur Creek, other small tributaries
Primary outflows	Baker River
Catchment area	270 square miles (700 km2)
Basin countries	United States
Built	April 1, 1924 (1924-04-01)
First flooded	September 1, 1925 (1925-09-01)
Max. length	7.5 miles (12.1 km)
Max. width	1 mile (1.6 km)
Surface area	2,190 acres (8.9 km2)
Average depth	70 feet (21 m)
Max. depth	280 feet (85 m)
Water volume	161,470 acre-feet (199,170,000 m3)[1]
Surface elevation	436 feet (133 m) at full pool
Frozen	In winter
Islands	1, unnamed, near north end
Settlements	Concrete

Lake Shannon is a long, narrow reservoir on the Baker River in Skagit County, Washington in the United States.^[2] Formed in the 1920s by the construction of an arch dam just above the town of Concrete, the lake is approximately 7.5 miles (12 km) long and averages 0.6 miles (1 km) wide when full. Located just outside the western boundary of North Cascades National Park, Lake Shannon serves as the lower reservoir for Puget Sound Energy's Baker River Hydroelectric Project.

Before the creation of Lake Shannon, the area was used primarily for fur trapping, logging, and concrete making. The construction of Lower Baker Dam blocked salmon migration in the Baker River. An artificial fish passage system was begun in the 1950s and completed in 1959 after the construction of Upper Baker Dam, located upstream of Lake Shannon. The lake has abundant landlocked kokanee salmon, the by-product of salmon spawning in lake tributaries. Fishing, boating and water skiing are popular recreational activities on the lake.