The Sumas River is a

river A river is a natural stream of fresh water that flows on land or inside Subterranean river, caves towards another body of water at a lower elevation, such as an ocean, lake, or another river. A river may run dry before reaching the end of ...

in the Fraser Lowland and a

tributary A tributary, or an ''affluent'', is a stream or river that flows into a larger stream (''main stem'' or ''"parent"''), river, or a lake. A tributary does not flow directly into a sea or ocean. Tributaries, and the main stem river into which they ...

of the

Fraser River The Fraser River () is the longest river within British Columbia, Canada, rising at Fraser Pass near Blackrock Mountain (Canada), Blackrock Mountain in the Rocky Mountains and flowing for , into the Strait of Georgia just south of the City of V ...

system A system is a group of interacting or interrelated elements that act according to a set of rules to form a unified whole. A system, surrounded and influenced by its open system (systems theory), environment, is described by its boundaries, str ...

, coursing across the international border between the

Canadian province Canada has ten provinces and three territories that are sub-national administrative divisions under the jurisdiction of the Constitution of Canada, Canadian Constitution. In the 1867 Canadian Confederation, three provinces of British North Amer ...

British Columbia British Columbia is the westernmost Provinces and territories of Canada, province of Canada. Situated in the Pacific Northwest between the Pacific Ocean and the Rocky Mountains, the province has a diverse geography, with rugged landscapes that ...

and the

U.S. state In the United States, a state is a constituent political entity, of which there are 50. Bound together in a political union, each state holds governmental jurisdiction over a separate and defined geographic territory where it shares its so ...

of Washington.

Course

The Sumas River originates in the

Sumas Mountain Sumas Mountain is a mountain located in Whatcom County, Washington, 15 miles northeast of Bellingham and southwest of Vedder Mountain. Located in the Skagit Range, the mountain is notable for its high biodiversity and year-round hiking tra ...

(American Sumas) in Whatcom County, Washington, with its

creeks draining the mountain's western and northern slopes. These

headwater The headwater of a river or stream is the geographical point of its beginning, specifically where surface runoff water begins to accumulate into a flowing channel of water. A river or stream into which one or many tributary rivers or streams flo ...

confluence In geography, a confluence (also ''conflux'') occurs where two or more watercourses join to form a single channel (geography), channel. A confluence can occur in several configurations: at the point where a tributary joins a larger river (main ...

west of the mountain just north of Lawrence where the nearby

Nooksack River The Nooksack River is a river in western Whatcom County of the northwestern U.S. state of Washington (state), Washington, draining Nooksack Valley, extensive valley systems within the North Cascades around Mount Shuksan, Mount Baker and the Twin ...

exits the Nooksack Valley, and the resultant river then flows north first past Nooksack before coursing generally northeast past the town of Sumas (where it picks up Johnson Creek, the first of its only two left tributaries) and crosses the

Canada–United States border The international border between Canada and the United States is the longest in the world by total length. The boundary (including boundaries in the Great Lakes, Atlantic, and Pacific coasts) is long. The land border has two sections: Canada' ...

. The Sumas River then runs further northeast, crosses the

Trans-Canada Highway The Trans-Canada Highway (Canadian French, French: ; abbreviated as the TCH or T-Can) is a transcontinental federal–provincial highway system that travels through all ten provinces of Canada, from the Pacific Ocean on the west coast to the A ...

near Kilgard (where it picks up Marshall Creek, the second of its only two left tributaries) and reaches the southeastern side of a mountain within the Fraser Valley known as the Canadian Sumas. It then flows along the mountain's base, draining a wide flatland on its right bank known as the

Sumas Prairie Sumas Prairie is a landform in British Columbia, Canada and the State of Washington, United States. Part of the Fraser Lowland, it was created by the draining of Sumas Lake early in the 20th Century, and extends from the Vedder Canal southwest ...

(where the Sumas Lake used to exist), before joining the Vedder River and emptying into the

around the mountain's northeastern tip.

History

The Sumas River used to flow into the Sumas Lake, a massive but shallow

lake A lake is often a naturally occurring, relatively large and fixed body of water on or near the Earth's surface. It is localized in a basin or interconnected basins surrounded by dry land. Lakes lie completely on land and are separate from ...

surrounded by expansive

wetland A wetland is a distinct semi-aquatic ecosystem whose groundcovers are flooded or saturated in water, either permanently, for years or decades, or only seasonally. Flooding results in oxygen-poor ( anoxic) processes taking place, especially ...

s on the floodplain between the Canadian Sumas and

Vedder Mountain The Vedder Mountain is a branch of the Cascade Range in the Pacific Northwest, located at the southeastern edge of the Fraser Lowland in British Columbia, Canada, between the village of Yarrow, British Columbia, Yarrow and the village of Cultus Lak ...

. After a devastating flood all over the Fraser basin in 1894, the lake was artificially drained in the 1920s via the construction of the Vedder Canal, leaving behind a vast flatland later known as the

, which is now traversed by the tributary Saar Creek and the namesaked Sumas Drainage Canal. Swift Creek, a tributary of the Sumas River, is contaminated with naturally occurring

asbestos Asbestos ( ) is a group of naturally occurring, Toxicity, toxic, carcinogenic and fibrous silicate minerals. There are six types, all of which are composed of long and thin fibrous Crystal habit, crystals, each fibre (particulate with length su ...

-laden sediment from the slow-moving

Swift Creek Landslide The Swift Creek Landslide is an active, slow-moving landslide located in western Washington, USA, due east of Everson on Sumas Mountain. Asbestos-laden sediment originating from the landslide has recently generated much interest in this area. ...

References

{{authority control Tributaries of the Fraser River Rivers of Washington (state) Rivers of the Lower Mainland International rivers of North America Rivers of Whatcom County, Washington

Course

History

See also

References