|Location||Kittitas County, Washington|
|Type||natural lake, reservoir|
|Primary outflows||Yakima River|
|Catchment area||54.3 sq mi (141 km2)|
|Basin countries||United States|
|Max. length||4.2 mi (6.8 km)|
|Max. width||1 mi (1.6 km)|
|Water volume||157,800 acre feet (194,600,000 m3)|
|Surface elevation||2,517 ft (767 m)|
Keechelus Lake (// is a lake and reservoir in Washington state, USA. It is the source of the Yakima River. Keechelus Lake is the western lake of the three large lakes near Interstate 90 and north of the Yakima River in the Cascade Range, the other two being Kachess Lake in the middle and Cle Elum Lake to the east. After crossing nearby Snoqualmie Pass (elevation 3015 ft), Interstate 90 runs along the eastern shoreline of Keechelus Lake.
Keechelus Lake is part of the Columbia River basin, being the source of the Yakima River, which is tributary to the Columbia River.
The lake is used as a storage reservoir for the Yakima Project, an irrigation project run by the United States Bureau of Reclamation. Although a natural lake, Keechelus Lake's capacity and discharge is controlled by Keechelus Dam, a 128-foot (39 m) high earthfill structure built in 1917. As a storage reservoir, Keechelus Lake's active capacity is 157,900 acre feet (195,000,000 m³).
The name Keechelus comes from an Indian term meaning "few fish", in contrast to Kachess Lake, whose name means "more fish".
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