Osoyoos 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,...

 located in British Columbia

British Columbia

British Columbia is the westernmost of Canada's provinces and is known for its natural beauty, as reflected in its Latin motto, Splendor sine occasu . Its name was chosen by Queen Victoria in 1858...

 and Washington. Osoyoos is derived from the word suius meaning "narrowing of the waters" in the local Okanagan language (Syilx'tsn).

Located on the lakeshore are the towns of Osoyoos, British Columbia

Osoyoos, British Columbia

Osoyoos is a town in the southern part of the Okanagan Valley in British Columbia near the border with Washington state. The town is also adjacent to the Indian Reserve of the Osoyoos Indian Band. The origin of the name Osoyoos was the word suius meaning "narrowing of the waters" in the local...

 and Oroville, Washington

Oroville, Washington

Oroville is a town in Okanogan County, Washington, United States. The population was 1,686 at the 2010 census.-Geography:Oroville is located at ....

. The lake's maximum elevation is 912.78 ft (278.2 m), while its minimum elevation is 909.46 ft (277.2 m). The 62-year average discharge into the Okanogan River

Okanogan River

The Okanogan River is a tributary of the Columbia River, approximately 115 mi long, in southern British Columbia and north central Washington...

 at Oroville is 683 cuft/s. Maximum discharge in 2004 was 1340 cuft/s. Washington's Osoyoos Lake State Park

Osoyoos Lake State Park

Osoyoos Lake State Park in Okanogan County, Washington is a camping park in the Washington State Park System. It consists of of sandy lakeshore, green lawns, and shade trees on Osoyoos Lake, in contrast with the hot, arid conditions that prevail in the area. Available activities include boating,...

 is located on its shore.

An international lake

Osoyoos Lake and its outlet and primary inflow, the Okanogan River

Okanogan River

The Okanogan River is a tributary of the Columbia River, approximately 115 mi long, in southern British Columbia and north central Washington...

, are subject to international water-sharing agreements governed by the International Joint Commission

International Joint Commission

The International Joint Commission is an independent binational organization established by the United States and Canada under the Boundary Waters Treaty of 1909.The Commission has responsibilities related to the following treaties and agreements:...

 as part of the Columbia Basin

Columbia Basin

The Columbia Basin, the drainage basin of the Columbia River, occupies a large area–about —of the Pacific Northwest region of North America. In common usage, the term often refers to a smaller area, generally the portion of the drainage basin that lies within eastern Washington.Usage of the term...

. The authority responsible for overseeing the IJC agreements is the International Osoyoos Lake Board of Control, composed of appointees from Environment Canada

Environment Canada

Environment Canada , legally incorporated as the Department of the Environment under the Department of the Environment Act Environment Canada (EC) (French: Environnement Canada), legally incorporated as the Department of the Environment under the Department of the Environment Act Environment...

, the BC Ministry of Water, Land Air Protection, the US Army Corps of Engineers, the US Geological Survey, and private consultants.