The Sammamish River (also known as Sammamish Slough) flows through north
King County, Washington
King County is located in the U.S. state of Washington. The population was 2,269,675 in the 2020 census, making it the most populous county in Washington, and the 13th-most populous in the United States. The county seat is Seattle, also the st ...
for about , draining
Lake Sammamish
Lake Sammamish is a freshwater lake east of Seattle in King County, Washington, United States. The lake is long and wide, with a maximum depth of and a surface area of . It lies east of Lake Washington and west of the Sammamish Plateau, a ...
into
Lake Washington. Along its course, the Sammamish River flows through
Redmond,
Woodinville
Woodinville is a city in King County, Washington, United States. It is a part of the Seattle metropolitan area. There is also a much larger population with Woodinville mailing addresses in adjacent unincorporated areas of King ( Cottage Lake) and ...
,
Bothell
Bothell () is a city in King and Snohomish counties in the U.S. state of Washington. It is part of the Seattle metropolitan area, situated near the northeast end of Lake Washington. As of the 2020 census, it had a population of 48,161 resident ...
, and
Kenmore.
The river is named after the
native people
Indigenous peoples are culturally distinct ethnic groups whose members are directly descended from the earliest known inhabitants of a particular geographic region and, to some extent, maintain the language and culture of those original people ...
who once lived along its entire length.
Course
The Sammamish River begins as an outlet on the north shore of
Lake Sammamish
Lake Sammamish is a freshwater lake east of Seattle in King County, Washington, United States. The lake is long and wide, with a maximum depth of and a surface area of . It lies east of Lake Washington and west of the Sammamish Plateau, a ...
, which in turn is fed by several creeks that make up the headwaters of the Sammamish River basin. The most important of these is
Issaquah Creek.
The river flows north from the lake through the city of Redmond. The tributary
Bear Creek joins the Sammamish from the east, also containing the waters from
Evans Creek and
Cottage Lake Creek.
After passing through Redmond and parts of unincorporated King County, the Sammamish enters Woodinville where it turns northwest and then west.
Little Bear Creek joins the Sammamish at this western turning point from the north. The river continues to bend in a generally westward direction, where it is joined from the north by
North Creek in Bothell near the
University of Washington
The University of Washington (UW, simply Washington, or informally U-Dub) is a public research university in Seattle, Washington.
Founded in 1861, Washington is one of the oldest universities on the West Coast; it was established in Seattle a ...
, and
Swamp Creek in Kenmore.
The Sammamish River enters
Lake Washington on the west side of Kenmore.
The Sammamish River basin covers an area from
Everett in the north to
May Valley in the south. It is part of the larger Lake Washington-Cedar River drainage
.
[The Sammamish Watershed]
" ''King County Department of Natural Resources and Parks.'' Retrieved on May 9, 2008. The total basin drainage area covers approximately 626 km
2 (242 mi
2), including the surface of Lake Sammamish. Big Bear Creek is the largest of the four major tributaries that feed the river followed by Little Bear Creek, North Creek, and Swamp Creek. There is also a significant amount of more diffuse drainage, primarily originating from the hills and valley to the west of the river.
River modifications
The Sammamish River of the early 1900s has been extensively modified as a result of various human efforts to use the channel for navigation, to utilize the floodplain for agriculture, and to reduce flooding in the Sammamish River valley and Lake Sammamish. Prior to major hydrologic modifications that began in the early 1900s, the river was wider and deeper and generally flowed more slowly due to a relatively small difference in elevation between Lake Sammamish and Lake Washington. Prior to these modifications, the river was known as Squak Slough (after a modified pronunciation of the native village at
Issaquah
Issaquah ( ) is a city in King County, Washington, United States. The population was 40,051 at the 2020 census. Located in a valley and bisected by Interstate 90, the city is bordered by the Sammamish Plateau to the north and the " Issaquah Al ...
) and was navigable over its entire length by shallow-draft steamers and was used to float logs and coal barges from Lake Sammamish to Lake Washington. The mouth of the river was east of its present position.
Although early drainage and navigation improvement efforts in the first couple of decades of the 20th century likely affected the form and function of the river, the most significant modifications occurred as a result of two largely federal-funded navigation and flood control projects. The first major change occurred as a result of the reduction in the mean level and seasonal elevation range of Lake Washington in 1916 as part of the development of the
Lake Washington Ship Canal and
Lock
Lock(s) may refer to:
Common meanings
*Lock and key, a mechanical device used to secure items of importance
*Lock (water navigation), a device for boats to transit between different levels of water, as in a canal
Arts and entertainment
* ''Lock ...
system, which officially opened June 16, 1917. This effectively increased the elevation difference between Lake Sammamish and Lake Washington and increased the flow rate of the river. It also moved the mouth of the river westward.
The second major change resulted from a King County/ACOE channel dredging, straightening project completed in November 1964 that included construction of a
weir
A weir or low head dam is a barrier across the width of a river that alters the flow characteristics of water and usually results in a change in the height of the river level. Weirs are also used to control the flow of water for outlets of l ...
at the Lake Sammamish source. This project practically eliminated flooding in the Sammamish River valley and reduced maximum flood elevations and seasonal water surface elevations in Lake Sammamish. The weir was modified in 1998 to improve passage for anadromous salmon during low flow.
Natural history
The Sammamish River is home to several runs of
salmon
Salmon () is the common name for several list of commercially important fish species, commercially important species of euryhaline ray-finned fish from the family (biology), family Salmonidae, which are native to tributary, tributaries of the ...
and
trout
Trout are species of freshwater fish belonging to the genera '' Oncorhynchus'', ''Salmo'' and ''Salvelinus'', all of the subfamily Salmoninae of the family Salmonidae. The word ''trout'' is also used as part of the name of some non-salmoni ...
, including
chinook,
coho
The coho salmon (''Oncorhynchus kisutch;'' Karuk: achvuun) is a species of anadromous fish in the salmon family and one of the five Pacific salmon species. Coho salmon are also known as silver salmon or "silvers". The scientific species name is ...
,
sockeye
The sockeye salmon (''Oncorhynchus nerka''), also called red salmon, kokanee salmon, blueback salmon, or simply sockeye, is an anadromous species of salmon found in the Northern Pacific Ocean and rivers discharging into it. This species is a P ...
,
kokanee,
steelhead
Steelhead, or occasionally steelhead trout, is the common name of the anadromous form of the coastal rainbow trout or redband trout (O. m. gairdneri). Steelhead are native to cold-water tributaries of the Pacific basin in Northeast Asia and N ...
, and
coastal cutthroat trout
The coastal cutthroat trout (''Oncorhynchus clarkii clarkii''), also known as the sea-run cutthroat trout, blue-back trout or harvest trout, is one of the several subspecies of cutthroat trout found in Western North America. The coastal cutthroa ...
.
[Known Freshwater Distribution of Salmon and Trout for WRIA 8 (Greater Lake Washington Watershed)]
" ''King County Department of Natural Resources and Parks.'' Retrieved on July 20, 2009. The
King County government is currently working on restoring fish habitat along the river.
[Willowmoor Reach Restoration]
" ''King County Department of Natural Resources and Parks.'' Retrieved on July 20, 2009.
Several species of birds and mammals are plentiful along the river, including waterfowl such as
Canada geese
The Canada goose (''Branta canadensis''), or Canadian goose, is a large wild goose with a black head and neck, white cheeks, white under its chin, and a brown body. It is native to the arctic and temperate regions of North America, and it is o ...
,
duck
Duck is the common name for numerous species of waterfowl in the family Anatidae. Ducks are generally smaller and shorter-necked than swans and geese, which are members of the same family. Divided among several subfamilies, they are a form t ...
s, and the
great blue heron
The great blue heron (''Ardea herodias'') is a large wading bird in the heron family Ardeidae, common near the shores of open water and in wetlands over most of North America and Central America, as well as the Caribbean and the Galápagos ...
.
Bald eagles
The bald eagle (''Haliaeetus leucocephalus'') is a bird of prey found in North America. A sea eagle, it has two known subspecies and forms a species pair with the white-tailed eagle (''Haliaeetus albicilla''), which occupies the same niche as ...
and
beavers
Beavers are large, semiaquatic rodents in the genus ''Castor'' native to the temperate Northern Hemisphere. There are two extant species: the North American beaver (''Castor canadensis'') and the Eurasian beaver (''C. fiber''). Beavers a ...
are also common sights near the river.
Recreation
The
Sammamish River Trail
The Sammamish River Trail is a bike path and recreational rail trail in King County, Washington that runs along the Sammamish River from Blyth Park in Bothell to Marymoor Park in Redmond as part of the “Locks to Lakes Corridor.” It connec ...
is a paved bicycle and walking trail that runs along the river, from
Marymoor Park
Marymoor Park, located on the north end of Lake Sammamish in Redmond, Washington, is King County's largest, oldest, and most popular park, with more than 3 million annual visitors coming to roam its . Among recreational activities available are ...
in Redmond, to Bothell, where it connects to the
Burke-Gilman Trail to
Seattle
Seattle ( ) is a seaport city on the West Coast of the United States. It is the seat of King County, Washington. With a 2020 population of 737,015, it is the largest city in both the state of Washington and the Pacific Northwest regio ...
. The Slough is also the main geographical feature of the former Wayne Golf Course in Bothell. The river is also the home o
Sammamish Rowing Associationwhich is a non-profit community rowing facility based on King County Parks property on the West
shore supporting recreational and competitive rowing for high school and adult rowers. The Sammamish Rowing facility and boathouse are West of the river, with the dock right along the West Shore of the river, opposite
Marymoor Dog Park.
See also
*
List of rivers of Washington
This is a list of rivers in the U.S. state of Washington.
By drainage basin
This list is arranged by drainage basin. Respective tributaries are indented under each larger stream's name and are ordered downstream to upstream.
Fraser River (Britis ...
References
External links
Sammamish WatershedU.S. Geological Survey names query form
{{authority control
Rivers of King County, Washington
Rivers of Washington (state)