The Okanagan Basin spans two countries and comprises the basin of

Okanagan Lake Okanagan Lake ( oka, kɬúsx̌nítkw) is a lake in the Okanagan Valley of British Columbia, Canada. The lake is long, between wide, and has a surface area of 348 km2 (135 sq. mi.). Hydrography Okanagan Lake is called a fjord lake as i ...

, the

Okanogan River The Okanogan River (known as the Okanagan River in Canada) is a tributary of the Columbia River, approximately 115 mi (185 km) long, in southern British Columbia and north central Washington. It drains a scenic plateau region called th ...

and tributary valleys such as that of the Similkameen and

Chelan River The Chelan River is a tributary of the Columbia River, in the U.S. state of Washington. Just long, it is the shortest river in Washington. Lake Chelan Dam is located at the river's source: the outlet of Lake Chelan. Nearly the entire river's fl ...

s. In Canada the basin constitutes two distinct regions within

British Columbia British Columbia (commonly abbreviated as BC) is the westernmost province of Canada, situated between the Pacific Ocean and the Rocky Mountains. It has a diverse geography, with rugged landscapes that include rocky coastlines, sandy beaches, ...

, the

Similkameen Country The Similkameen Country, also referred to as the Similkameen Valley or Similkameen District, but generally referred to simply as The Similkameen or more archaically, Similkameen, is a region roughly coinciding with the basin of the river of the sam ...

to the west and the main

Okanagan The Okanagan ( ), also known as the Okanagan Valley and sometimes as the Okanagan Country, is a region in the Canadian province of British Columbia defined by the basin of Okanagan Lake and the Canadian portion of the Okanagan River. It is part ...

region running from the communities of

Osoyoos Osoyoos (, ) is the southernmost town in the Okanagan Valley in British Columbia between Penticton and Omak. The town is north of the United States border with Washington state and is adjacent to the Osoyoos Indian reserve. The origin of the na ...

in the south to Armstrong in the north – incorporating most of the three Okanagan regional districts and is usually known as "the Okanagan" or as the Okanagan Valley or the Okanagan Country. In the

United States The United States of America (U.S.A. or USA), commonly known as the United States (U.S. or US) or America, is a country primarily located in North America. It consists of 50 states, a federal district, five major unincorporated territorie ...

, the Okanogan Country is the western, lowland core of

Okanogan County Okanogan County () is a county located in the U.S. state of Washington along the Canada–U.S. border. As of the 2020 census, the population was 42,104. The county seat is Okanogan, while the largest city is Omak. Its area is the largest in ...

, which like its Canadian counterpart has a history and economy based on ranching, gold, fruit orcharding and vineyards, but the basin includes

Lake Chelan Lake Chelan ( ) is a narrow, long lake in Chelan County, north-central Washington state, U.S. Before 1927, it was the largest natural lake in the state by any measure. Upon the completion of Lake Chelan Dam in 1927, the elevation of the lake w ...

and other flanking valleys. Communities in Washington's Okanogan Basin include

Pateros Pateros, officially the Municipality of Pateros ( tgl, Bayan ng Pateros), is the lone municipality of Metro Manila, Philippines. According to the 2020 census, it has a population of 63,643 people. This municipality is famous for its duck-rai ...

Omak Omak ( Merriam (1997), p. 869) is a city located in the foothills of the Okanogan Highlands in north-central Washington, United States. With an estimated 4,845 residents as of 2010, distributed over a land area of , Omak is the largest municipa ...

, Okanogan, Oroville and Brewster. Almost 200 km long and 8000 km² in area, the Canadian portion of the Okanagan watershed is approximately 2/3 the size of

Vancouver Island Vancouver Island is an island in the northeastern Pacific Ocean and part of the Canadian Provinces and territories of Canada, province of British Columbia. The island is in length, in width at its widest point, and in total area, while are o ...

. Okanagan Lake dominates the basin which contains many small lakes and watercourses. The Okanagan Valley was carved out by glaciers, and when the ice retreated approximately 10,000 years ago, the Canadian portion of the basin was filled with one huge waterbody, Lake Penticton. The Valley was scoured to something like its current state when an ice dam at the southern end of Lake Penticton melted, emptying most of the valley. The Canadian Environmental Grantmakers’ Network considers the Okanagan Basin to be the most arid watershed in Canada, with an urgent need for effective water management. The

Okanagan Basin Water Board The Okanagan Basin Water Board (OBWB) is a water governance body designated to identify and resolve critical water issues for the Okanagan watershed in British Columbia, Canada. It was set up to implement the recommendations of the Okanagan Basin St ...

was established more than 35 years ago, to provide leadership on regional water issues, taking a basin-wide perspective and seeking collaborative solutions.Okanagan Basin Water Board
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References

Okanagan Basin'', Okanagan Nation Alliance website
Okanagan Geography of Washington (state) {{Washington-geo-stub

See also

References