Malheur Lake

Malheur Lake
Satellite image of Malheur Lake (right) and Harney Lake (left)
Malheur Lake Location of Malheur Lake in Oregon
Location	Harney County, Oregon
Coordinates	43°19′58″N 118°47′35″W / 43.33278°N 118.79306°W / 43.33278; -118.79306Coordinates: 43°19′58″N 118°47′35″W / 43.33278°N 118.79306°W / 43.33278; -118.79306
Type	Natural, eutrophic in an endorheic basin
Primary inflows	Donner und Blitzen River, Silvies River, Sodhouse Spring, precipitation
Primary outflows	Mud Lake (frequent but intermittent flows)
Catchment area	3,083 sq mi (7,980 km2)
Basin countries	United States
Surface area	49,700 acres (20,100 ha)
Average depth	2 ft (0.61 m)
Max. depth	5 ft (1.5 m)
Water volume	84,500 acre·ft (104,200,000 m3)
Residence time	7.4 years
Shore length1	58 mi (93 km)
Surface elevation	4,093 ft (1,248 m)
Islands	Cole, Pelican
Settlements	Burns, Crane, New Princeton
References
1 Shore length is not a well-defined measure.

Malheur Lake is one of the lakes in the Malheur National Wildlife Refuge in Harney County in the U.S. state of Oregon. Located about 18 miles (29 km) southeast of Burns, the lake is a marsh fed by the Donner und Blitzen River from the south and the Silvies River from the north. Malheur Lake periodically overflows into Mud Lake to the west and thence to Harney Lake, the sink of Harney Basin.

The western area of Malheur Lake consists of ponds separated by small islands and peninsulas. The lake's central and eastern sections are more open. The generally shallow water is suitable habitat for migratory birds, waterfowl, and aquatic plants.

As is typical of Great Basin lakes, Malheur Lake's surface area changes dramatically with the local weather, climate, and season because the lake is in a very flat basin. A large influence on the water volume is local snow melt, especially from Steens Mountain, south of the lake. For example, large snowpacks in the mid-1980s caused the lake to expand from approximately 67 to 160 square miles (170 to 410 km²) within three years, flooding usually dry areas and damaging a branch of the Oregon Eastern Railway. Soon afterward, drought in the early 1990s reduced the lake size to just 200 acres (0.31 sq mi), exposing large mudflats and dusty playas.

Malheur Lake is a remnant of a much larger lake that drained east to the Malheur River, a tributary of the Snake River. The size of this ancient lake, which existed during a wetter climate, has been estimated at 900 square miles (2,300 km²), with a maximum depth of 35 feet (11 m). Its outlet was originally a channel near New Princeton, but lava flows diverted the water to a gap near Crane. Much of the original lake bottom has since turned into desert or become meadows periodically watered by lake overflows. Mud Lake and Harney Lake are also remnants of the original pluvial lake.