Lake Washington

Lake Washington Xacuabš
The longest and second longest floating bridges in the world cross Lake Washington
Lake Washington and surrounding area
Location	King County, Washington, United States
Coordinates	47°37′0″N 122°15′53″W / 47.61667°N 122.26472°W / 47.61667; -122.26472 (Lake Washington)Coordinates: 47°37′0″N 122°15′53″W / 47.61667°N 122.26472°W / 47.61667; -122.26472 (Lake Washington)
Primary inflows	Sammamish, Cedar Rivers; Ravenna, Thornton, Kelsey, Juanita, and Coal Creeks
Primary outflows	Lake Washington Ship Canal (1916)
Catchment area	315,000 acres (1,270 km2)
Basin countries	United States
Max. length	22 mi (35 km)
Surface area	33.8 square miles (88 km2), 33.8 square miles (21,600 acres)
Average depth	108 ft (33 m)
Max. depth	214 ft (65 m)
Water volume	2,400,000 acre·ft (3.0 km3)
Surface elevation	16 ft (4.9 m) above mean sea level, 20.6 ft (6.3 m) above Puget Sound mean lower low tide
Islands	Mercer Island, Foster Island, Marsh Island, Ohler's Island, Pritchard Island

Lake Washington is a large freshwater lake adjacent to the city of Seattle. It is the largest lake in King County and the second largest natural lake in the state of Washington, after Lake Chelan. It borders the cities of Seattle on the west, Bellevue and Kirkland on the east, Renton on the south and Kenmore on the north, and encloses Mercer Island. The lake is fed by the Sammamish River at its north end and the Cedar River at its south.

Lake Washington received its present name in 1854 after Thomas Mercer suggested it be named after George Washington, as the new Washington Territory had been named the year before. Prior names for Lake Washington have included the Duwamish name Xacuabš (Lushootseed: literally great-amount-of-water), as well as Lake Geneva, Lake Duwamish, and the Chinook jargon name, "Hyas Chuck," meaning, "Big Lake."

The lake provides great sport fishing opportunities. Some species found in this lake are Coastal Cutthroat Trout, Rainbow Trout, Largemouth Bass, Smallmouth Bass, Yellow Perch, and Black Crappie.

A ribbon lake, Lake Washington is long, narrow and finger-like. Ribbon lakes are excavated by glaciers. As the Puget lobe of the Cordilleran Ice Sheet flowed south near the end of the , it met bands of harder and softer rock. Erosion of the softer rock was faster and a linear depression was created in the flow direction. When the glacier melted, the lake filled with the meltwater, which was retained by moraine deposits. A dam can also be created by the bands of harder rock either side of the softer rock. There is usually a river at both ends of a ribbon lake, one being the inlet, and the other, the outlet—though in the case of present-day Lake Washington, inlet rivers are located at both ends, with a man-made outlet in the middle.