Editing Columbia River (section)

== Watershed ==
{{Main|Columbia River drainage basin}}

[[File:08gorge2.jpeg|thumb|alt=A big river winds through a landscape of sparsely vegetated hills and bluffs. Dark rock faces contrast sharply with a bright blue sky veiled with intermittent white and gray clouds. In the foreground, an open space between bluffs opens on the river.|Near [[The Gorge Amphitheatre]] in [[George, Washington]]]]

Most of the Columbia's drainage basin (which, at {{convert|258000|mi2|km2|disp=or}}, is about the size of France)<ref name="BLM">{{cite web |last1 = Booth |first1 = Bibi |last2 = Fischman |first2 = Shelly |title = The Columbia River Basin |publisher = U.S. Bureau of Land Management |url = http://www.blm.gov/education/00_resources/articles/Columbia_river_basin/article.html |archive-url = https://web.archive.org/web/20080411153836/http://www.blm.gov/education/00_resources/articles/Columbia_river_basin/article.html |archive-date = April 11, 2008 }}</ref> lies roughly between the Rocky Mountains on the east and the Cascade Mountains on the west. In the United States and Canada the term watershed is often used to mean drainage basin. The term ''Columbia Basin'' is used to refer not only to the entire drainage basin but also to subsets of the river's watershed, such as the relatively flat and unforested area in eastern Washington bounded by the Cascades, the Rocky Mountains, and the Blue Mountains.{{sfn|Meinig|1995|p=4}} Within the watershed are diverse landforms including mountains, arid plateaus, river valleys, rolling uplands, and deep gorges. [[Grand Teton National Park]] lies in the watershed, as well as parts of [[Yellowstone National Park]], [[Glacier National Park (U.S.)|Glacier National Park]], [[Mount Rainier National Park]], and [[North Cascades National Park]]. Canadian National Parks in the watershed include [[Kootenay National Park]], [[Yoho National Park]], [[Glacier National Park (Canada)|Glacier National Park]], and [[Mount Revelstoke National Park]]. Hells Canyon, the deepest gorge in North America,<ref name="BLM" /> and the [[Columbia Gorge]] are in the watershed. Vegetation varies widely, ranging from [[Tsuga heterophylla|western hemlock]] and [[Thuja plicata|western redcedar]] in the moist regions to [[sagebrush]] in the arid regions.<ref name="ISAB" /> The watershed provides habitat for 609&nbsp;known fish and wildlife species, including the [[bull trout]], [[bald eagle]], [[gray wolf]], [[grizzly bear]], and [[Canada lynx]].<ref name="BLM" />

The [[World Wide Fund for Nature]] (WWF) divides the waters of the Columbia and its tributaries into three [[freshwater ecoregion]]s: Columbia Glaciated, Columbia Unglaciated, and Upper Snake. The Columbia Glaciated ecoregion, about a third of the total watershed, lies in the north and was covered with ice sheets during the Pleistocene. The ecoregion includes the mainstem Columbia north of the Snake River and tributaries such as the Yakima, Okanagan, Pend Oreille, Clark Fork, and Kootenay rivers. The effects of [[glacier|glaciation]] include a number of large lakes and a relatively low diversity of freshwater fish. The Upper Snake ecoregion is defined as the Snake River watershed above [[Shoshone Falls]], which totally blocks fish migration. This region has 14&nbsp;species of fish, many of which are [[endemism|endemic]]. The Columbia Unglaciated ecoregion makes up the rest of the watershed. It includes the mainstem Columbia below the Snake River and tributaries such as the Salmon, John Day, Deschutes, and lower Snake Rivers. Of the three ecoregions it is the richest in terms of freshwater species diversity. There are 35&nbsp;species of fish, of which four are endemic. There are also high levels of mollusk endemism.{{sfn|Abell|Olsen|Dinerstein|Hurley|2000|pp=166–69}}<ref>{{cite web |url = http://www.feow.org/ecoregion_details.php?eco=120 |title = Columbia Glaciated |publisher = World Wide Fund for Nature and The Nature Conservancy |year = 2008 |access-date = September 25, 2008 |archive-url = https://web.archive.org/web/20131101053119/http://www.feow.org/ecoregion_details.php?eco=120 |archive-date = November 1, 2013 |url-status = dead }}; {{cite web |url = http://www.feow.org/ecoregion_details.php?eco=121 |archive-url = https://web.archive.org/web/20131101052230/http://www.feow.org/ecoregion_details.php?eco=121 |archive-date = November 1, 2013 |url-status = dead |title = Columbia Unglaciated |publisher = World Wide Fund for Nature and The Nature Conservancy |year = 2008 |access-date = September 25, 2008 }}; {{cite web |url = http://www.feow.org/ecoregion_details.php?eco=122 |archive-url = https://web.archive.org/web/20131101062512/http://www.feow.org/ecoregion_details.php?eco=122 |archive-date = November 1, 2013 |url-status = dead |title = Upper Snake |publisher = World Wide Fund for Nature and The Nature Conservancy |year = 2008 |access-date = September 25, 2008 }}</ref>

In 2016, over eight million people lived within the Columbia's drainage basin. Of this total about 3.5&nbsp;million people lived in Oregon, 2.1&nbsp;million in Washington, 1.7&nbsp;million in Idaho, half a million in British Columbia, and 0.4&nbsp;million in Montana. Population in the watershed has been rising for many decades and is projected to rise to about 10&nbsp;million by 2030. The highest population densities are found west of the Cascade Mountains along the [[Interstate 5|I-5]] corridor, especially in the Portland-Vancouver urban area. High densities are also found around [[Spokane, Washington]], and [[Boise, Idaho]]. Although much of the watershed is rural and sparsely populated, areas with recreational and scenic values are growing rapidly. The central Oregon county of [[Deschutes County, Oregon|Deschutes]] is the fastest-growing in the state. Populations have also been growing just east of the Cascades in central Washington around the city of [[Yakima, Washington|Yakima]] and the Tri-Cities area. Projections for the coming decades assume growth throughout the watershed. The Canadian part of the [[Okanagan]] subbasin is also growing rapidly.<ref name="ISAB">{{cite web |last1 = Bilby |first1 = Robert |last2 = Hanna |first2 = Susan |last3 = Huntly |first3 = Nancy |author-link3=Nancy Huntly|title = Human Population Impacts on Columbia River Basin Fish and Wildlife |publisher = Independent Scientific Advisory Board |date = July 8, 2007 |url = http://www.nwcouncil.org/library/isab/isab2007-3.pdf |access-date = September 15, 2008 |display-authors = etal |archive-url = https://web.archive.org/web/20130117052954/http://www.nwcouncil.org/library/isab/isab2007-3.pdf |archive-date = January 17, 2013 |url-status = dead |df = mdy-all }}</ref>

Climate varies greatly within the watershed. Elevation ranges from sea level at the river mouth to more than {{convert|14000|ft|m}} in the mountains, and temperatures vary with elevation. The highest peak is [[Mount Rainier]], at {{convert|14411|ft|m}}. High elevations have cold winters and short cool summers; interior regions are subject to great temperature variability and severe droughts. Over some of the watershed, especially west of the Cascade Mountains, precipitation maximums occur in winter, when Pacific storms come ashore. Atmospheric conditions block the flow of moisture in summer, which is generally dry except for occasional thunderstorms in the interior.<ref name="ISAB" /> In some of the eastern parts of the watershed, especially [[shrub-steppe]] regions with [[Continental climate]] patterns, precipitation maximums occur in early summer.<ref name="nwdwm">{{cite web |title = Columbia River Water Management Report, Chapter 2 |publisher = U.S. Army Corps of Engineers, Water Management Division |year = 2005 |url = http://www.nwd-wc.usace.army.mil/crwmg/reports/bluebook/2005/Chapter2%202005.pdf |access-date = September 19, 2008 |archive-url = https://web.archive.org/web/20140812175319/http://www.nwd-wc.usace.army.mil/crwmg/reports/bluebook/2005/Chapter2%202005.pdf |archive-date = August 12, 2014 |url-status = dead }}</ref> Annual precipitation varies from more than {{convert|100|in|cm}} a year in the Cascades to less than {{convert|8|in|cm}} in the interior. Much of the watershed gets less than {{convert|12|in|cm}} a year.<ref name="ISAB" />

Several major North American drainage basins and many minor ones border the Columbia River's drainage basin. To the east, in northern Wyoming and Montana, the [[Continental Divide]] separates the Columbia watershed from the Mississippi-Missouri watershed, which empties into the [[Gulf of Mexico]]. To the northeast, mostly along the southern border between British Columbia and [[Alberta]], the Continental Divide separates the Columbia watershed from the [[Nelson River|Nelson]]-[[Lake Winnipeg]]-[[Saskatchewan River|Saskatchewan]] watershed, which empties into Hudson Bay. The Mississippi and Nelson watersheds are separated by the [[Laurentian Divide]], which meets the Continental Divide at [[Triple Divide Peak (Montana)|Triple Divide Peak]] near the headwaters of the Columbia's [[Flathead River]] tributary. This point marks the meeting of three of North America's main drainage patterns, to the Pacific Ocean, to Hudson Bay, and to the Atlantic Ocean via the Gulf of Mexico.<ref name="watershed-map">{{cite web |title = Watersheds (map) |publisher = Commission for Environmental Cooperation |year = 2006 |url = http://www.cec.org/naatlas/img/NA-Watersheds.gif |archive-url = http://webarchive.loc.gov/all/20080807145118/http://www.cec.org/naatlas/img/NA-Watersheds.gif |archive-date = August 7, 2008 |url-status = dead }}</ref><ref name="gonzalez">{{cite web |title = Continental Divides in North Dakota and North America |work = North Dakota Geological Survey Newsletter |last = Gonzalez |first = Mark A. |year = 2003 |url = https://www.dmr.nd.gov/ndgs/NEWSLETTER/NLS03/pdf/Divide.pdf |access-date = September 12, 2008 |archive-url = https://web.archive.org/web/20130117052801/https://www.dmr.nd.gov/ndgs/NEWSLETTER/NLS03/pdf/Divide.pdf |archive-date = January 17, 2013 |url-status = dead }}</ref>

Further north along the Continental Divide, a short portion of the combined Continental and Laurentian divides separate the Columbia watershed from the [[Mackenzie River|Mackenzie]]-[[Slave River|Slave]]-[[Athabasca River|Athabasca]] watershed, which empties into the Arctic Ocean. The Nelson and Mackenzie watersheds are separated by a divide between streams flowing to the Arctic Ocean and those of the [[List of Hudson Bay rivers|Hudson Bay watershed]].<ref>{{cite web |title = Atlas of Canada: Drainage Basins |url = http://geogratis.gc.ca/api/en/nrcan-rncan/ess-sst/dc475fb0-8893-11e0-9ab7-6cf049291510.html |publisher = Natural Resources Canada |year = 2010 |access-date = September 29, 2015 |archive-url = https://web.archive.org/web/20160314090740/http://geogratis.gc.ca/api/en/nrcan-rncan/ess-sst/dc475fb0-8893-11e0-9ab7-6cf049291510.html |archive-date = March 14, 2016 |url-status = live }}</ref> This divide meets the Continental Divide at [[Snow Dome (Canada)|Snow Dome]] (also known as Dome), near the northernmost bend of the Columbia River.{{sfn|Palmer|Thorington|1921|p=119}}

To the southeast, in western Wyoming, another divide separates the Columbia watershed from the [[Colorado River|Colorado]]–[[Green River (Colorado River)|Green]] watershed, which empties into the [[Gulf of California]]. The Columbia, Colorado, and Mississippi watersheds meet at Three Waters Mountain in the [[Wind River Range]] of {{nowrap|Wyoming}}.<ref>{{cite journal |last = Gonzalez |first = Mark A. |title = Continental Divides in North Dakota and North America |journal = NGDS Newsletter |volume = 30 |number = 1 |pages = 5–6 |publisher = North Dakota Geological Survey |year = 2002 |url = https://www.dmr.nd.gov/ndgs/Newsletter/NLS03/pdf/Divide.pdf |access-date = December 2, 2016 |url-status = dead |archive-url = https://web.archive.org/web/20130117052801/https://www.dmr.nd.gov/ndgs/NEWSLETTER/NLS03/pdf/Divide.pdf |archive-date = January 17, 2013 }}</ref> To the south, in Oregon, Nevada, Utah, Idaho, and Wyoming, the Columbia watershed is divided from the [[Great Basin]], whose several watersheds are [[endorheic basin|endorheic]], not emptying into any ocean but rather drying up or sinking into [[sump]]s.<ref name="watershed-map" /> Great Basin watersheds that share a border with the Columbia watershed include [[Harney Basin]], [[Humboldt River]], and [[Great Salt Lake]].<ref name="watershed-map" /> The associated triple divide points are Commissary Ridge North, Wyoming,<ref>{{cite peakbagger |pid = 5429 |name = Commissary Ridge North, Wyoming }}</ref> and Sproats Meadow Northwest, Oregon.<ref>{{cite peakbagger |pid = 3248 |name = Sproats Meadow Northwest, Oregon }}</ref> To the north, mostly in British Columbia, the Columbia watershed borders the [[Fraser River]] watershed. To the west and southwest the Columbia watershed borders a number of smaller watersheds that drain to the Pacific Ocean, such as the Klamath River in Oregon and California and the [[Puget Sound]] Basin in Washington.<ref name="watershed-map" />

=== Major tributaries ===
{{See also|List of tributaries of the Columbia River}}
[[File:Deschutes River.jpg|thumb|alt=A relatively small river winds through a series of sparsely vegetated brown hills under a nearly cloudless blue sky. The river and the low hills are in shade, while the hilltops and a large hillside in the foreground are sunlit.|The Deschutes River at its confluence with the Columbia]]

The Columbia receives more than 60&nbsp;significant [[tributary|tributaries]]. The four largest that empty directly into the Columbia (measured either by [[discharge (hydrology)|discharge]] or by size of watershed) are the Snake River (mostly in Idaho), the Willamette River (in northwest Oregon), the Kootenay River (mostly in British Columbia), and the Pend Oreille River (mostly in northern Washington and Idaho, also known as the lower part of the Clark Fork). Each of these four averages more than {{convert|20000|cuft/s|m3/s}} and drains an area of more than {{convert|20000|mi2|km2}}.

The Snake is by far the largest tributary. Its watershed of {{convert|108000|mi2|km2}} is larger than the state of Idaho. Its discharge is roughly a third of the Columbia's at the rivers' confluence but compared to the Columbia upstream of the confluence the Snake is longer (113%) and has a larger drainage basin (104%).

The Pend Oreille River system (including its main tributaries, the Clark Fork and Flathead rivers) is also similar in size to the Columbia at their confluence. Compared to the Columbia River above the two rivers' confluence, the Pend Oreille-Clark-Flathead is nearly as long (about 86%), its basin about three-fourths as large (76%), and its discharge over a third (37%).<ref name="wdr2007us">Calculated mainly with data from: {{cite web |url = https://wdr.water.usgs.gov/wy2007/search.jsp |title = Water-resources data for the United States, Water Year 2007 |publisher = United States Geological Survey |access-date = September 16, 2008 |archive-url = https://web.archive.org/web/20081206000126/http://wdr.water.usgs.gov/wy2007/search.jsp |archive-date = December 6, 2008 |url-status = dead }}</ref>

[[File:Kp'itl'els (Brilliant, BC), Sinixt village site and historic home of the Alex Christian family.jpg|thumb|Kp'itl'els ([[Brilliant, British Columbia|Brilliant]]), Sinixt village site at the confluence of the Kootenay and Columbia Rivers|alt=View of an overgrown field with a rotting fencepost in the foreground and a range of hills in the distance]]

{| class="wikitable collapsible sortable state = uncollapsed"
|-
![[Tributary]]
!colspan=2|Average discharge
!colspan=2|Drainage basin
|-
!
![[cubic feet per second|ft<sup>3</sup>/s]]
![[cubic meters per second|m<sup>3</sup>/s]]
!mi<sup>2</sup>
!km<sup>2</sup>
|-
|[[Snake River]]
|{{convert|56900|cuft|m3|sigfig=3|disp=table}}<ref name="USGSrivers" />
|{{convert|107500|mi2|km2|sigfig=4|disp=table}}<ref>{{cite web |title = USGS Water Resources of the United States: Boundary Descriptions and Names of Regions, Subregions, Accounting Units and Cataloging Units |publisher = United States Geological Survey |year = 2007 |url = http://water.usgs.gov/GIS/huc_name.html |access-date = September 16, 2008 |archive-url = https://web.archive.org/web/20170625160942/https://water.usgs.gov/GIS/huc_name.html |archive-date = June 25, 2017 |url-status = live }}'' Sum of Subregion 1704, Upper Snake, Subregion 1705, Middle Snake, and Subregion 1706, Lower Snake.</ref>
|-
|[[Willamette River]]
|{{convert|37400|cuft|m3|sigfig=3|disp=table}}<ref name="USGSrivers" />
|{{convert|11500|mi2|km2|sigfig=4|disp=table}}<ref>{{cite web |title = Willamette Watershed |url = https://www.portlandonline.com/bes/index.cfm?c=32749 |publisher = Portland Bureau of Environmental Services |year = 2008 |access-date = September 16, 2008 |archive-url = https://web.archive.org/web/20170415010826/https://www.portlandoregon.gov/bes/30938 |archive-date = April 15, 2017 |url-status = live }}</ref>
|-
|[[Kootenay River]] (Kootenai)
|{{convert|30650|cuft|m3|sigfig=3|disp=table}}<ref name="nwcouncil">[http://www.nwcouncil.org/fw/subbasinplanning/kootenai/plan/Assessment_01IntroOverview.pdf Subbasin Overview] {{Webarchive|url=https://web.archive.org/web/20090325213657/http://www.nwcouncil.org/fw/subbasinplanning/kootenai/plan/Assessment_01IntroOverview.pdf |date=March 25, 2009 }} , [http://www.nwcouncil.org/fw/subbasinplanning/kootenai/plan/ Kootenai Subbasin Plan] {{Webarchive|url=https://web.archive.org/web/20080921122638/http://www.nwcouncil.org/fw/subbasinplanning/kootenai/plan/ |date=September 21, 2008 }}, Northwest Power and Conservation Council</ref>
|{{convert|19420|mi2|km2|sigfig=4|disp=table}}<ref>{{cite web |url = http://virtualmuseum.ca/Exhibitions/Hydro/en/stories/rivers.php |title = Balance of Power: Hydroelectric Development in Southeastern British Columbia |publisher = Touchstones Nelson: Museum of Art and History |year = 2007 |access-date = September 16, 2008 |archive-url = https://web.archive.org/web/20111106161101/http://virtualmuseum.ca/Exhibitions/Hydro/en/stories/rivers.php |archive-date = November 6, 2011 |url-status = dead }}</ref>
|-
|[[Pend Oreille River]]
|{{convert|26430|cuft|m3|sigfig=3|disp=table}}<ref>{{cite web |title = Pend Oreille, Kettle, and Colville River Basins, and the Columbia River from the International Boundary to the confluence with the Spokane River |publisher = United States Geological Survey |year = 2005 |url = http://pubs.usgs.gov/wdr/2005/wdr-wa-05-1/pdf/wa00103ADR2005_Figure48.pdf |access-date = October 19, 2008 |archive-url = https://web.archive.org/web/20081018080145/http://pubs.usgs.gov/wdr/2005/wdr-wa-05-1/pdf/wa00103ADR2005_Figure48.pdf |archive-date = October 18, 2008 |url-status = live }} Discharge data taken from a gauge at the US–Canada border, {{convert|16.1|mi|km}} from the mouth, measuring data from about {{convert|25200|mi2|km2}}, about 98&nbsp;percent of the total watershed.</ref>
|{{convert|25800|mi2|km2|sigfig=3|disp=table}}<ref name="bchydro">{{cite web |url = http://www.llbc.leg.bc.ca/public/pubdocs/bcdocs/409063/seven_mile_project.pdf |title = Seven Mile Project Water Use Plan |publisher = BC Hydro |date = December 8, 2006 |access-date = September 3, 2009 |archive-url = https://web.archive.org/web/20170822011818/http://www.llbc.leg.bc.ca/public/pubdocs/bcdocs/409063/seven_mile_project.pdf |archive-date = August 22, 2017 |url-status = dead }}</ref>
|-
|[[Cowlitz River]]
|{{convert|9140|cuft|m3|sigfig=3|disp=table}}<ref>{{cite web |title = Water-data report 2007: USGS 14243000 Cowlitz River at Castle Rock, WA |url = http://wdr.water.usgs.gov/wy2007/pdfs/14243000.2007.pdf |publisher = United States Geological Survey |year = 2007 |access-date = October 24, 2008 |archive-url = https://web.archive.org/web/20081029095450/http://wdr.water.usgs.gov/wy2007/pdfs/14243000.2007.pdf |archive-date = October 29, 2008 |url-status = dead }} Discharge data taken from gauge 14243000 at [[Castle Rock, Washington|Castle Rock]], {{convert|17.3|mi|km}} from the mouth, measuring the flow from about {{convert|2238|sqmi|km2}} or 85&nbsp;percent of the total watershed.</ref>
|{{convert|2586|mi2|km2|sigfig=3|disp=table}}<ref>
Calculated by summing subbasin sizes listed in [http://www.nwcouncil.org/fw/subbasinplanning/lowerColumbia/plan/Vol%20II%20H--L%20Columbia%20Tribs.pdf Lower Columbia Tributaries] {{Webarchive|url=https://web.archive.org/web/20081002170752/http://www.nwcouncil.org/fw/subbasinplanning/lowerColumbia/plan/Vol%20II%20H--L%20Columbia%20Tribs.pdf |date=October 2, 2008 }} , Northwest Power and Conservation Council; and [http://www.nwcouncil.org/fw/subbasinplanning/lowerColumbia/plan/2004_05/ManagementPlan/VolumeII/MP%20Vol%20II%20Ch%2008%20Toutle2.pdf Toutle Management Plan] {{Webarchive|url=https://web.archive.org/web/20081002170813/http://www.nwcouncil.org/fw/subbasinplanning/lowerColumbia/plan/2004_05/ManagementPlan/VolumeII/MP%20Vol%20II%20Ch%2008%20Toutle2.pdf |date=October 2, 2008 }}, Northwest Power and Conservation Council. Retrieved on September 16, 2008.
</ref>
|-
|[[Spokane River]]
|{{convert|7900|cuft|m3|sigfig=3|disp=table}}{{sfn|Benke|Cushing|2005|p=650}}
|{{convert|6680|mi2|km2|sigfig=3|disp=table}}<ref name="USGS-rivers" />
|-
|[[Lewis River (Washington)|Lewis River]]
|{{convert|6125|cuft|m3|sigfig=3|disp=table}}<ref name="subbasin plan">{{cite web |last = Lower Columbia Fish Recovery Board |title = volume II&nbsp;– Subbasin Plan Chapter G&nbsp;– NF and EF Lewis |work = Lower Columbia Salmon Recovery and Fish & Wildlife Subbasin Plan |publisher = Northwest Power and Conservation Council |date = December 2004 |url = http://www.nwcouncil.org/fw/subbasinplanning/lowerColumbia/plan/Vol%20II%20G--Lewis.pdf |access-date = October 14, 2008 |archive-url = https://web.archive.org/web/20060823103132/http://www.nwcouncil.org/fw/subbasinplanning/lowerColumbia/plan/Vol%20II%20G--Lewis.pdf |archive-date = August 23, 2006 |url-status = dead |df = mdy-all }}</ref>
|{{convert|1046|mi2|km2|sigfig=3|disp=table}}<ref name="vulcan">{{cite web |title = Description: Lewis River Drainage, Mount St. Helens, Washington |publisher = United States Geological Survey |year = 1999 |url = http://vulcan.wr.usgs.gov/Volcanoes/MSH/Hydrology/Drainages/Lewis/description_lewis.html |access-date = October 14, 2008 |archive-url = https://web.archive.org/web/20081006201419/http://vulcan.wr.usgs.gov/Volcanoes/MSH/Hydrology/Drainages/Lewis/description_lewis.html |archive-date = October 6, 2008 |url-status = live }}</ref>
|-
|[[Deschutes River (Oregon)|Deschutes River]]
|{{convert|5845|cuft|m3|sigfig=3|disp=table}}{{sfn|Loy|Allan|Buckley|Meacham|2001|pp=164–65}}
|{{convert|10700|mi2|km2|sigfig=3|disp=table}}<ref name="USGS-rivers" />
|-
|[[Yakima River]]
|{{convert|3542|cuft|m3|sigfig=3|disp=table}}<ref>{{cite web |publisher = United States Geological Survey |url = http://pubs.usgs.gov/wdr/2005/wdr-wa-05-1/pdf/wa00103ADR2005_Figure60.pdf |title = Yakima River and Esquatzel Coulee Basins and the Columbia River from Richland to Kennewick, Water Resources Data-Washington Water Year 2005 |access-date = October 16, 2008 |archive-url = https://web.archive.org/web/20081018074714/http://pubs.usgs.gov/wdr/2005/wdr-wa-05-1/pdf/wa00103ADR2005_Figure60.pdf |archive-date = October 18, 2008 |url-status = live }} Discharge data from gauge 12510500 at Kiona, {{convert|29.9|mi|km}} from the mouth, measuring the flow from about 91&nbsp;percent of the total watershed.</ref>
|{{convert|6150|mi2|km2|sigfig=3|disp=table}}<ref>{{cite web |url = http://www.nwcouncil.org/fw/subbasinplanning/yakima/plan/1_Overview.pdf |title = Yakima Subbasin Plan Overview |publisher = Northwest Power and Conservation Council |access-date = September 16, 2008 |archive-url = https://web.archive.org/web/20081002170908/http://www.nwcouncil.org/fw/subbasinplanning/yakima/plan/1_Overview.pdf |archive-date = October 2, 2008 |url-status = dead }}</ref>
|-
|[[Wenatchee River]]
|{{convert|3079|cuft|m3|sigfig=2|disp=table}}<ref>{{cite web |publisher = United States Geological Survey |url = http://pubs.usgs.gov/wdr/WDR-WA-02-1/data/12459000.2002.sw.pdf |title = Wenatchee River Basin: 12459000 Wenatchee River at Peshastin, WA |access-date = October 16, 2008 |archive-url = https://web.archive.org/web/20121008191739/http://pubs.usgs.gov/wdr/WDR-WA-02-1/data/12459000.2002.sw.pdf |archive-date = October 8, 2012 |url-status = live }}. Discharge data from gauge 12459000 at Peshastin, {{convert|21.5|mi|km}} from the mouth, measuring the flow from about {{convert|1000|mi2|km2}} or 77&nbsp;percent of the total watershed.</ref>
|{{convert|1350|mi2|km2|sigfig=3|disp=table}}<ref name="USGS-rivers">{{cite web |url = http://water.usgs.gov/GIS/huc_name.html |title = Boundary Descriptions and Names of Regions |publisher = United States Geological Survey |access-date = September 10, 2008 |archive-url = https://web.archive.org/web/20120427215107/http://water.usgs.gov/GIS/huc_name.html |archive-date = April 27, 2012 |url-status = live }}</ref>
|-
|[[Okanogan River]]
|{{convert|3039|cuft|m3|sigfig=2|disp=table}}<ref>[http://pubs.usgs.gov/wdr/2005/wdr-wa-05-1/ Water Data Report WA-05-1] {{Webarchive|url=https://web.archive.org/web/20070429052414/http://pubs.usgs.gov/wdr/2005/wdr-wa-05-1/ |date=April 29, 2007 }}, chapter [http://pubs.usgs.gov/wdr/2005/wdr-wa-05-1/pdf/wa00103ADR2005_Figure52.pdf Okanagan River Basin] {{Webarchive|url=https://web.archive.org/web/20081018075111/http://pubs.usgs.gov/wdr/2005/wdr-wa-05-1/pdf/wa00103ADR2005_Figure52.pdf |date=October 18, 2008 }}. Retrieved on April 20, 2007. Discharge data taken at [[Malott, Washington]], {{convert|17|mi|km}} from the mouth, measuring the flow from about {{convert|8080|sqmi|km2}}, about 97&nbsp;percent of the total watershed.</ref>
|{{convert|8200|mi2|km2|sigfig=3|disp=table}}<ref>{{cite web |author = School of Natural Resources |url = http://www.snre.umich.edu/ecomgt//pubs/transboundary/Okanagan.pdf |page = 2 |year = 2001 |title = Okanagan River Basin |publisher = University of Michigan |access-date = September 29, 2015 |archive-url = https://web.archive.org/web/20170701065515/http://www.snre.umich.edu/ecomgt/pubs/transboundary/Okanagan.pdf |archive-date = July 1, 2017 |url-status = live }}</ref>
|-
|[[Kettle River (Columbia River)|Kettle River]]
|{{convert|2925|cuft|m3|sigfig=2|disp=table}}<ref>{{cite web |title = Water-Data Report 2007: 12404500 Kettle River near Laurier, WA |publisher = United States Geological Survey |year = 2007 |url = http://wdr.water.usgs.gov/wy2007/pdfs/12404500.2007.pdf |access-date = October 18, 2008 |archive-url = https://web.archive.org/web/20120220145826/http://wdr.water.usgs.gov/wy2007/pdfs/12404500.2007.pdf |archive-date = February 20, 2012 |url-status = dead }} Discharge data from a gauge near Laurier, {{convert|29.71|mi|km}} from the mouth, measuring the flow from about {{convert|3800|mi2|km2}}, about 90&nbsp;percent of the total watershed.</ref>
|{{convert|4200|mi2|km2|sigfig=4|disp=table}}<ref name="upper columbia">{{cite web |url = http://www.nwcouncil.org/fw/subbasinplanning/admin/level2/intermtn/plan/29_uprcol_overview.pdf |title = Upper Columbia Subbasin Overview |pages = 29–8 |publisher = Northwest Power and Conservation Council |access-date = September 16, 2008 |archive-url = https://web.archive.org/web/20081002170918/http://www.nwcouncil.org/fw/subbasinplanning/admin/level2/intermtn/plan/29_uprcol_overview.pdf |archive-date = October 2, 2008 |url-status = dead |df = mdy-all }}</ref>
|-
|[[Sandy River (Oregon)|Sandy River]]
|{{convert|2257|cuft|m3|sigfig=2|disp=table}}<ref name="usgs">{{cite web |title = Water-Data Report 2007: 14142500 Sandy River Below Bull Run River, near Bull Run, OR |publisher = United States Geological Survey |year = 2008 |url = http://wdr.water.usgs.gov/wy2007/pdfs/14142500.2007.pdf |access-date = October 19, 2008 |archive-url = https://web.archive.org/web/20120220145835/http://wdr.water.usgs.gov/wy2007/pdfs/14142500.2007.pdf |archive-date = February 20, 2012 |url-status = dead }} Discharge data from a gauge near Bull Run, {{convert|18.4|mi|km}} from the mouth, measuring the flow from about {{convert|436|mi2|km2}}, about 86&nbsp;percent of the total watershed.</ref>
|{{convert|508|mi2|km2|sigfig=4|disp=table}}<ref name="Taylor">{{cite web |last = Taylor |first = Barbara |title = Salmon and Steelhead Runs and Related Events of the Sandy River Basin&nbsp;– A Historical Perspective |publisher = Portland General Electric |date = December 1998 |url = http://www.portlandgeneral.com/community_environment/initiatives/protecting_fish/sandy_river/docs/sandy_river_history_full.pdf |access-date = December 18, 2010 |url-status = dead |archive-url = https://web.archive.org/web/20150427184240/https://www.portlandgeneral.com/community_environment/initiatives/protecting_fish/sandy_river/docs/sandy_river_history_full.pdf |archive-date = April 27, 2015 |df = mdy }}</ref>
|-
|[[John Day River]]
|{{convert|2060|cuft|m3|sigfig=2|disp=table}}<ref>{{cite web |title = Water-Data Report 2007: 14048000 John Day River at McDonald Ferry, OR |publisher = United States Geological Survey |year = 2007 |url = http://wdr.water.usgs.gov/wy2007/pdfs/14048000.2007.pdf |access-date = October 19, 2008 |archive-url = https://web.archive.org/web/20120220145844/http://wdr.water.usgs.gov/wy2007/pdfs/14048000.2007.pdf |archive-date = February 20, 2012 |url-status = dead }} Discharge data from a gauge at McDonald Ferry, {{convert|20.9|mi|km}} from the mouth, measuring the flow from about {{convert|7580|mi2|km2}}, about 95&nbsp;percent of the total watershed.</ref>
|{{convert|8010|mi2|km2|sigfig=4|disp=table}}<ref>{{cite web |last1 = Powell |first1 = Russ |last2 = Delano |first2 = Kenneth |title = John Day River Subbasin Fish Habitat Enhancement Project |publisher = Bonneville Power Administration |year = 2004 |url = http://pisces.bpa.gov/release/documents/documentviewer.aspx?pub=H00005632-3.pdf |access-date = October 18, 2008 |archive-url = https://web.archive.org/web/20081029095450/http://pisces.bpa.gov/release/documents/documentviewer.aspx?pub=H00005632-3.pdf |archive-date = October 29, 2008 |url-status = dead }}</ref>
 |}
{{clear}}