Malheur Lake is a lake

Lake

A lake is a body of relatively still fresh or salt water of considerable size, localized in a basin, that is surrounded by land. Lakes are inland and not part of the ocean and therefore are distinct from lagoons, and are larger and deeper than ponds. Lakes can be contrasted with rivers or streams,...

 in an arid region of eastern Oregon

Oregon

Oregon is a state in the Pacific Northwest region of the United States. It is located on the Pacific coast, with Washington to the north, California to the south, Nevada on the southeast and Idaho to the east. The Columbia and Snake rivers delineate much of Oregon's northern and eastern...

, United States

United States

The United States of America is a federal constitutional republic comprising fifty states and a federal district...

 near Burns, Oregon

Burns, Oregon

Burns is a city in and the county seat of Harney County, Oregon, United States. As of the 2010 census the population was 2,806.-History:Burns was established in the early 1880s and incorporated upon Harney county's creation in 1889...

. The lake is fed by Donner und Blitzen River

Donner und Blitzen River

The Donner und Blitzen River is a river on the eastern Oregon high desert which drains a relatively arid basin, the southern portion of Harney Basin, from roughly 20 to 80 miles south-southeast of Burns including Malheur National Wildlife Refuge...

 from the south and the Silvies River

Silvies River

The Silvies River flows for about through Grant and Harney counties in the U.S. state of Oregon. The river drains of the northern Harney Basin....

 from the north. Malheur Lake has no outlet, though water escapes through ground seepage and by evaporation; widespread regional irrigation may or may not have an effect. At the bottom of Harney Basin

Harney Basin

The Harney Basin is a structural basin in southeastern Oregon in the United States at the northwestern corner of the Great Basin. One of the least populated areas of the contiguous United States, it is located largely in northern Harney County, bounded on the north and east by the Columbia Plateau,...

, also Harney Lake

Harney Lake

Harney Lake is a shallow alkali lake basin located in southeast Oregon, United States, approximately thirty miles south of the town of Burns. The lake lies within the boundary of the Malheur National Wildlife Refuge and is the lowest point in the Blitzen Valley drainage.- History :The lake has been...

is a "twin" which, historically, merges with Malheur Lake when the water levels rise sufficiently. This last happened in the mid-1980s.