Middle Columbia River – McNary Pool GRP

  • Interim update: October 2023
  • Last full update: 2017
  • Open for full update: May 2024
  • Email max.gordon@ecy.wa.gov with questions and comments!

Table of Contents

Site Description

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This chapter provides a description of the physical features, hydrology, climate, and winds, found along the Middle Columbia River (MCR) corridor and includes an overview of the oil spill risks in the region.  The Columbia River travels 1,243 miles, originating in British Columbia, Canada and running through Washington, providing a border between Washington and Oregon before eventually entering the Pacific Ocean.  Although the Columbia River originates in Canada, the NOAA river mile system used in these geographic response plans (GRPs) begins at the confluence of the river with the Pacific.  The Lower Columbia River Geographic Response Plan (LCR-GRP) starts at river mile one and ends at the base of the U.S. Army Corps of Engineers (USACE) Bonneville Lock and Dam located at river mile 145.4. The Middle Columbia Region begins at river mile 145.4 on the upstream side of the Bonneville Lock and Dam and is subdivided into four separate GRPs, each a specific pool created by one of four USACE dams in the region: Bonneville, The Dalles, John Day, and McNary.

The MCRM-GRP encompasses the McNary Pool (a.k.a. Lake Wallula), and covers a 50.5 mile reach of the Columbia River, running primarily north, from the upstream side of the McNary Lock and Dam (located at river mile M-292.5).  Portions of WRIA: 31 (Rock Glade), 32 (Walla Walla), 33 (Lower Snake), 36 (Esquatzel-Coulee), and 40 (Alkali-Squilchuck) fall within this planning area, as well as the Oregon John Day and Umatilla watersheds.  The McNary Pool borders Benton, Walla Walla, and Franklin counties in Washington where the McNary Pool-GRP ends at the border between the Tri-Cities and the Hanford Site.  On the Oregon side of the river, starting at the McNary Damn, the McNary Pool borders Gilliam, Morrow and Umatilla Counties before reaching the state line located at river mile 310.  Included within the McNary Pool-GRP are short sections of the both the Snake and Yakima Rivers.  The section of the Snake River within the GRP runs from its confluence with the Columbia River at river mile MSN-0, upstream to the base of the USACE Ice Harbor Lock and Dam located at river mile MSN-9.6.  Similarly, the confluence of the Yakima River, located at YAK-0, is included in the McNary Pool-GRP and response strategies have been developed within the first four miles of the Yakima, up to the I-182 Bridge at river mile YAK-4.0.  Additional GRPs, have been developed for the upper (YAKU-GRP) and lower (YAK-GRP) Yakima River.

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Physical Features

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Volcanic activity built up a stratum of mud, ash, and lava in the geologic column in the area now known as eastern and central Washington and Oregon during the Eocene (55.8-33.9 million years ago), Oligocene (33.9-23 million years ago),  and Miocene (23-5.3 million years ago) Epochs. Basalt flows then covered the area in layers, forming a strong foundation of basaltic rock.  Subsequent lava and ash eruptions raised the Cascade Mountains during the Miocene Epoch, and the mountains began to lift when hundreds of volcanoes erupted during the Pleistocene Epoch (2.6 million – 11,700 years ago).  As the mountains rose, the Columbia River carved out a deep gorge.  Towards the end of the Pleistocene (~16,000-14,000 years ago) the Missoula floods battered the gorge over 100 times when the Missoula Lake was repeatedly breached, releasing high velocity debris-filled waters to a height of 900 feet and scouring the landscape with a discharge of 10 million cubic feet per second.  This intense geomorphic action formed the sheer basalt cliffs that are now emblematic of the Columbia River Gorge National Scenic Area.  This series of events has been described as one of the greatest flood occurrences in the history of the earth.

The nearly vertical cliffs of the Gorge are vulnerable to landslides, four of which occurred approximately 500 years ago, covering five square miles near Bonneville where they blocked the Columbia River and created a land bridge.  The land bridge was located in the area of the current bridge known as “The Bridge of the Gods” and was perhaps the origin of the name, having been passed down through oral tradition.  The dam formed by the land bridge created a lake of approximately the same size as the modern day Bonneville Pool, although within a few months the Columbia River breached this natural dam creating a flood 100 feet deep at Troutdale, OR.  The Gorge is still susceptible to landslides; in 1984 two children were killed in a slide along Interstate 84 near Cascade Locks.  In 1990 four highway workers were injured near Troutdale, and in 1996 a landslide in the Dodeson/Warrendale area of Oregon destroyed numerous homes, before sweeping across the railroad line and Interstate 84.  The features of this area continue to be shaped by landslides and the geomorphology of the Columbia River’s flow.

The river runs through the eastern plateau/steppe and then cuts through the Cascade and Coastal Mountain Ranges before entering the Pacific Ocean with much of the MCR located within the Columbia River Gorge National Scenic Area.  As a result of the changing landscape, the climate surrounding the river changes drastically.  The western side of the Gorge includes rainforests with an average annual rainfall of 75 inches.  It is a place rich in wildlife, with forests, lakes, streams, wetlands, and more waterfalls than any other part of the country.  The eastern Gorge has an annual rainfall of less than 15 inches, consists of a shrub steppe ecosystem, and is a place of rock bluffs and rolling hills used for farming and ranching.

Humans have also had an impact on the Columbia River.  Archaeological evidence shows that nomads were staying in the Gorge over 14,500 years ago, and that settlements were established as early as 11,230 years ago. Well before the establishment of white settlements, the Native people had developed the largest trading center in the Northwest at the Long Narrows of The Dalles/Celilo Falls area.  Celilo is believed to be the oldest continuously inhabited community on the North American continent. The center linked a trade network that extended along the entire Pacific Coast and inland to the Great Plains.  Native people living on the Columbia River received a variety of trade goods from all across the region, much of it received in return for one of their most prized resources — salmon.  Salmon were central to the culture of the region’s peoples, a part of their religious belief system, providing sustenance and trade goods.

Europeans and Americans began exploring and trading in the Pacific Northwest in the late 18th and early 19th centuries.  In 1792 Captain Robert Gray explored the lower river and named it for his ship, the Columbia Rediva.  In 1805 the Lewis and Clark Expedition traveled down the Snake and into the Columbia River, arriving at The Dalles/Celilo Falls area, which Clark noted as being a “great mart of trade”.  Within the next 50 years numerous white settlements were established along the river by people following the Oregon Trail or arriving by ship via the Pacific Ocean.  The earliest treaties were negotiated with the region’s Native peoples in 1855, and by 1859 Oregon had become a state; Washington followed, with statehood granted in 1889.  The first salmon cannery was established on the river in 1866.  In 1873 the USACE began modifying the river to aid navigation by removing obstructions, and from 1876-1915 building canals.

The USACE further shaped the Middle Columbia River into its current form through the construction of dams, beginning with the Bonneville Lock and Dam started in 1934 and completed in 1938, to the McNary Lock and Dam finished in 1957, The Dalles Lock and Dam finished in 1960, and the John Day Lock and Dam, completed in 1971. The dams tamed the river’s once-notorious rapids and created the sub-sectional pools of the area.  Fish lost due to the creation of the dams were ensured by the Mitchell Act (1938) to be replenished by the creation of hatcheries.  The dams inundated many of the Native American’s traditional fishing areas and in 1939, In-Lieu sites were promised to the affected Tribes to compensate for their losses. The USACE began constructing    In-Lieu sites in 1953 and as of the publishing of this document in 2015 there are 31 sites located in the area covered within the MCR.

By taming the rapids, the dams allowed the river to function as an industrial transportation corridor, with ships running import containers and autos east from Portland, OR and Vancouver, WA through a series of locks up to the Tri-Cities area (Kennewick, Pasco, and Richland, WA), before continuing east via the Snake River to Lewiston, Idaho, where they eventually travel on to 43 states.  As of 2014, more than 4 million tons of petroleum products are received at terminals in Portland each year with approximately half of that volume barged upriver to inland ports. The river corridor also provides a route for the transport of grain from farms in the interior of the county to the river’s gateway at the Pacific Ocean.  The Columbia River is the number one export route in the nation for wheat and barley, number two for soybeans, and the third largest grain export gateway in the world.

The dams also provide irrigation and flood control, important to an area with substantial farmland (grains and livestock), as well as hydroelectric power to Oregon and Washington.  In addition, the Columbia River Gorge, renowned for its stunning beauty and spectacular history, supports tourism in the area, providing a wealth of recreational opportunities such as hiking, fishing, mountain biking, windsurfing, and kayaking.

Within the MCR, each pool has its own unique attributes and communities.  The McNary Pool is 50.5 miles long and has a capacity of 1,350,000 acre/feet. This reach of the river leaves Oregon and extends north into Washington past the confluence of both the Snake and Yakima Rivers to the Tri-Cities metropolitan area, ending at river mile 343, the beginning of the Hanford reach.  Washington communities along this stretch of the river include Finley, Burbank, and the Tri-Cities of Kennewick, Pasco, and Richland.  With a population of ~250,000, the Tri-Cities metropolitan area presents a sharp contrast in urban development from the other sections of the MCR; the next largest city on the bank of the river is The Dalles, with a population of ~15,000.

Despite the diverse change in scenery surrounding the river through each of its various pools, the shoreline habitats remain relatively consistent over the course of the MCR.  They can be characterized as: exposed rocky headlands, wave-cut platforms, pocket beaches along exposed rocky shores, sand beaches, sand and gravel beaches, sand and cobble beaches, sheltered rocky shores, and sheltered marshes.
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The Columbia River is the fourth largest river in North America and the largest in the Pacific Northwest.  It originates in Columbia Lake, high in the Canadian Rockies, where it first travels northwest, and then turns south entering the US in Washington, where it eventually turns west and forms the border between Washington and Oregon before flowing into the Pacific Ocean. The river travels a total of 1,243 miles, providing drainage for approximately 258,000 sq. miles of the Western United States and British Columbia, with numerous tributaries, both rivers and creeks, adding to the flow along the way.

The flow of water in the MCR-GRP’s 200 mile reach of the Columbia River is controlled by dam outflows within each pool.  The McNary Pool has an average elevation of 340 feet above mean sea level.  Tributary rivers within the McNary Pool include the Yakima (WA), Snake (WA), and Walla Walla (WA).  Portions of the Columbia River within the pool are included within six WRIAs: Rock/Glade (WRIA 31), Walla Walla (WRIA 32), Lower Snake (WRIA 33), Esquatzel Coulee (WRIA 36), Lower Yakima (WRIA 37), and Alkaki-Squilchuck (WRIA 40) watersheds. In this part of Washington, most of the precipitation arrives during the winter months when water demands are the lowest.  During the summer, the snowpack is gone, there is little rain, and naturally low stream flows are dependent on groundwater inflow.  At the same time, the demand for human uses, including irrigation, are at the yearly maximum.  This means that groundwater and surface water are least available when water demands are the highest.  On the Oregon side, the McNary Pool feeds into the Umatilla watershed, which has similar hydrology.

Rock/Glade (WRIA 31): Many areas of eastern Washington are arid, receiving less than 20 inches of rain annually.

Walla Walla (WRIA 32):  The Walla Walla Watershed located in southeastern Washington includes the Walla Walla River and the Touchet River with their numerous tributary creeks and streams.  Both rivers originate in the Blue Mountains with the Walla Walla River beginning from the Oregon portion of the range.  The annual precipitation in the Walla Walla Watershed ranges from less than 10 inches per year near its confluence with Columbia River, to 45 inches per year in the higher elevation mountainous areas.  Only a fraction of this precipitation becomes groundwater available for human and economic uses.

Lower Snake (WRIA 33): The Lower Snake Watershed is located in eastern Washington and includes a portion of the Snake River and its numerous tributary creeks and streams, lying between its confluences with the Palouse River and the Columbia River.  The Snake River originates in the mountains of Idaho and Wyoming.  The annual precipitation in the Lower Snake Watershed ranges from 8 inches per year near its confluence with Columbia River, to a little over 10 inches in the higher elevations.  Only a fraction of this precipitation becomes groundwater available for human and economic uses.

Esquatzel Coulee (WRIA 36):  The Esquatzel Coulee Watershed located in eastern Washington includes a number of small streams that are tributary to the Columbia River.  Many of these smaller streams are seasonal.  The annual precipitation in the Esquatzel Coulee Watershed ranges from 7 inches per year in the Mattawa area, to over 10 inches in the higher elevations.  Only a fraction of this precipitation becomes groundwater available for human and economic uses.  As spring turns to summer, snowpack melts.  This causes stream flows to increase, but after the snowpack is gone, stream flow declines considerably.  River flows then become dependent on groundwater inflow, late summer glacial melting, and rare precipitation events.

Lower Yakima (WRIA 37): Many areas of central Washington are arid, including the Lower Yakima WRIA, receiving less than 20 inches of rain annually.

Alkaki-Squilchuck (WRIA 40):  Alkaki-Squilchuck (WRIA 40):  The area containing the Alkaki-Squilchuck WRIA in central Washington is arid receiving less than 20 inches of rain annually.

Umatilla Watershed: Water management in the arid Umatilla Basin has become increasingly complex in recent years.  Competing demands from society for generating hydro-electric power, maintaining and restoring fisheries, restoring watershed health, providing water for growing communities, and increasing agricultural production through irrigation, have put water resources in the Umatilla Basin and throughout the northwest, under increasing pressure.

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Climate and Winds

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The West-East corridor of the Columbia Gorge through the Cascade mountain range creates a climate interaction between the Washington/Oregon coasts and the interior of the states.  Due to the geologic formations and the atmospheric pressure imbalance surrounding this area, strong wind is frequently channeled through the Gorge year round.  These conditions, in addition to the scenic surroundings, have made the Gorge a renowned sporting destination for windsurfing.  In the summer, the wind comes predominately from the west, while during the winter it will oscillate between east and west.  This channeled Gorge wind is a conduit for air temperature in the surrounding regions as it funnels warm maritime air inland, and cold interior wind towards the coast.

Western winds carrying moisture in the air from the Pacific are pushed up against the Coast Range, the Olympic Mountains, and finally the Cascade mountains, creating a phenomenon known as a rain shadow.  A rain shadow is an area on the leeward side of the mountains which is sheltered from the rain, creating a distinct shift in climate.  As the air rises to pass over the mountains it expands and cools, releasing moisture in the form of precipitation on the western flanks.  By the time these winds pass over the Cascades there is little moisture remaining, creating the shrub steppe ecosystem that is emblematic of Eastern Washington.

The McNary Pool, as the furthest pool east in the Middle Columbia River corridor, exhibits a dry continental climate.  At the McNary Dam, elevation 344 feet above mean sea level, the average annual temperature is 53°F, ranging from a mean low of 34°F in January, to a mean high of 73°F in July and August.  Recorded temperature extremes are -22°F and 111°F.  Mean annual precipitation is 8 inches with half occurring between the months of November and February.  Annual snowfall is 3 inches, with more than half occurring in December and January.

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Tides and Currents

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There are no tidally influenced areas within the MCR area.  The river’s flow is governed strictly by the various dams, with the USACE determining exactly when and how much water is allowed to pass through the spillways; there are no free-flowing waters.

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Risk Assessment

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The Columbia River is one of the principal resources found in the Pacific Northwest with a plethora of natural, cultural, and economic resources intrinsically connected to the river, all at risk of injury from oil spills.  Potential risks to these resources include large commercial vessels, roads, rail systems, pipelines, aircraft, recreational boating, and other factors.

Oil TypesBoth refined petroleum products and crude oil are transported in bulk within this planning area. Crude oil and refined products contain a mix of hydrocarbons with varying properties; different types of crude oil and refined products will behave differently when spilled. Recent changes in oil production have led to an increase in the movement of Bakken light crude and diluted bitumen from Canada transported through the planning area via rail.

Crude oil from the Bakken fields in North Dakota has properties similar to gasoline or diesel, and poses a higher risk of fire because much of it will evaporate quickly into flammable vapors.  Unlike gasoline, the heavier hydrocarbons in the crude will persist in the environment after the light ends evaporate or burn.  Bitumen from the oil sands in Alberta, Canada, is heavy, almost asphalt-like, until it is mixed with lighter oil products known as diluents to create diluted bitumen.  Once mixed, the diluted bitumen will initially float on water after being spilled.  Environmental conditions, such as the density of the receiving waters and sediment load of the receiving waters, will affect how long diluted bitumen floats.  As the light diluents evaporate, the remaining heavy constituents may sink into the water column. There are specific response actions recommended for non-floating oils, detailed in the Non-Floating Oil Spill Response Tool in the Northwest Area Contingency Plan (NWACP), Section 9412.

Large Commercial Vessel Traffic:  There is significant commercial movement through the Middle Columbia corridor which offers six separate port facilities, including the Ports of: Arlington, Hood River, The Dalles, Kennewick, Klickitat, and Skamania.  The Dalles Lock reports “an average of 8 million tons of cargo, mostly grain and petroleum products, passing through each year.”  Future oil movement along the Columbia River Vessel Route is estimated to reach 566 million gallons/yr (based on best annual estimates and 2013 data).  The potential for vessel collisions or groundings presents a significant spill risk.  Large commercial vessels typically carry significant amounts of heavy and blended fuel oils and other petroleum products, increasing the risk for sensitive resources to be impacted if an oil spill incident were to occur.

Road Systems:  Vehicle traffic on roadways pose an oil spill risk in areas where they run adjacent to the shoreline, or cross over lakes, rivers, creeks, and ditches, that drain into the Columbia River.  Several main highways run parallel to the river, including Highway 14 in Washington and Interstate-84 in Oregon.  Within the MCR area there are six major highway bridges that cross the Columbia River, two that cross the Yakima River, and one that crosses the Snake River.  In addition, there are approximately 30 smaller bridges or causeways where vehicles cross tributaries or small lakes on the shores of the Columbia.  A vehicle spill onto one of these bridges or roadways can cause fuel or oil to flow from hardened surfaces into the Columbia River or its tributaries.  Commercial trucks can contain hundreds to thousands of gallons of fuel and oil, especially fully loaded tank trunks, and may carry almost any kind of cargo, including hazardous waste or other material that would pose a risk to the environment.  Smaller vehicle accidents pose a risk as well — commensurate to the volume of fuel and oil they carry.

Rail Transportation and Facilities: Rail companies transport oil via both unit trains and manifest trains in this area.  Unit trains include: up to four locomotives, buffer cars, and 118 loaded tank cars transporting oil in 714-barrel (29,998 gallon) capacity USDOT-approved tank cars.  Manifest trains include: up to four locomotives, a mix of non-oil merchandise cars, and one or more 714-barrel (29,998 gallon) capacity USDOT-approved tank cars carrying refined oil products, such as diesel, lubrication oil, or gasoline.  These trains may include emptied tank cars, each with residual quantities of up to 1,800 gallons of crude oil or petroleum products.  Every train locomotive typically holds a few hundred gallons of engine lubrication oil, plus saddle tanks that each have an approximate capacity of 5,000 gallons of diesel fuel.  Manifest trains may also transport biological oils and non-petroleum chemicals.  Unit trains carrying crude currently operate on specific routes.  Unit trains carrying crude from the Bakken Formation in North Dakota enter Washington State near Spokane, continue along the Columbia River to Vancouver, and then head north along I-5.  Similar to the highways systems that run along much of the Columbia River, rail transportation runs closely parallel to the river banks throughout the Lower and Middle Columbia River areas.  BNSF Railroad’s Fallbridge Subdivision runs along the Columbia River on the Washington side, while Union Pacific’s Portland Subdivision runs along the opposing bank in Oregon.

Vancouver Energy is a facility proposed for the Port of Vancouver, which if approved, would initially handle one to two crude-by-rail trains per day, and would be capable of receiving an average of four per day.

Oil Pipelines:  Two pipeline terminals are located in the MCR area.  The Tidewater pipeline terminal and the Andeavor Logistics NW pipeline terminal are both situated in the McNary Pool, on the eastern shore of the Snake River near the its confluence with the Columbia in Pasco, Washington.  These facilities receive, store and distribute bulk liquid products such as gasoline, diesel, bio-fuels, fertilizer, and industrial/agricultural chemicals.  Along with the pipelines, the facilities are accessible by barge, rail, and truck.  A spill from a pipeline, or one of the other associated modes of transporting petroleum products, has the potential to significantly impact sensitive resources in the area.

Aircraft:  Several airports are located within the MCR area including the: Cascade Locks State Airport, Columbia Gorge Airport, Arlington Municipal Airport, and Tri-Cities Airport.  Landing strips at these airports are used for recreational, commercial, and transit purposes.  With airports in the area, the potential exists for aircraft failures during inbound or outbound flights that could result in a spill with a release of jet fuel to the Columbia River or its tributaries.

Recreational Boating:  Accidents involving recreational water craft on the Columbia River have the potential to result in spills of anywhere from a few gallons of gasoline, up to hundreds of gallons of diesel fuel.  Examples of such accidents include: collisions, a vessel grounding, catching on fire, sinking, or exploding.  These types of accidents, as well as problems with bilge discharges and refueling operations, the most typical types of spills to occur, have a negative impact on sensitive river resources.

Other Spill Risks:  Other potential oil spill risks in the area include: dam turbine mechanical failures, road run-off during rain events, on-shore or near shore construction activities where heavy equipment is being operated, and the migration of spilled oil through soil on lands adjacent to the river or along creek or stream banks.

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Resources at Risk

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This section provides a summary of natural, cultural, and economic resources at risk in the planning area, including those resources at risk from oils with the potential to sink or submerge. It provides general information on habitat, fish, and wildlife resources, and locations in the area where sensitive natural resource concerns have been identified. It offers a summary of cultural resources that include fundamental procedures for the discovery of cultural artifacts and human skeletal remains. General information about flight restrictions, wildlife deterrence, and oiled wildlife can be found near the end of this section. A list of economic resources in the area is provided in the appendix.

This section is purposely broad in scope and should not be considered comprehensive. Some of the sensitive resources described in this section cannot be addressed in Response Strategies and Priorities because it is not possible to conduct effective response activities in these locations. Additional information from private organizations or federal, state, tribal, and local government agencies should also be sought during spills.

This material is presented with enough detail to give general information about the area during the first phase of a spill response. During an actual incident, more information about resources at risk will be available from the Environmental Unit in the Planning Section.

Note: specific resource concerns related to areas that already have designated protection strategies may be found in the “Resources At Risk” column of the matrix describing the individual strategies.

The information provided in this section can be used in:

  • Assisting the Environmental Unit (EU) and Operations in developing ad hoc response strategies.
  • Providing resource-at-risk “context” to responders, clean-up workers, and others during the initial phase of a spill response in the GRP area.
  • Briefing responders and incident command staff that may be unfamiliar with sensitive resource concerns in the GRP area.
  • Providing background information for personnel involved in media presentations and public outreach during a spill incident.
  • Providing information on benthic and water column species or cultural resources present to assist in planning for oils with the potential to sink or submerge.

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Natural Resources at Risk – Summary

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This area is composed of a wide variety of aquatic, riparian, and upland habitats. These varied habitats support a complex diversity of wildlife species, including large and small mammals, songbirds, birds of prey, upland birds, and waterfowl, as well as numerous reptiles and amphibians. Some species are resident throughout the year; while others seasonally migrate through the sub-basin.

This area contains a wide variety of aquatic, riparian, and upland habitats. These habitats support many of Washington’s salmonid species as well as a complex diversity of other wildlife. In addition to those species directly at risk to oil spills, others (due to their life histories and/or behaviors) are unlikely to become directly oiled during a spill incident but may be disturbed by response operations such as cleanup and reconnaissance. Some of the bird species are resident throughout the year, but many others seasonally migrate through the area.

Several of the species found in this area have been classified under the Federal Endangered Species Act or by the Washington State Fish and Wildlife Commission.

Classification types are listed below:

  • Federal Endangered (FE)
  • Federal Threatened (FT)
  • Federal Candidate (FC)
  • State Endangered (SE)
  • State Threatened (ST)
  • State Sensitive (SS)

Federal and State Threatened, Endangered, and Sensitive species that may occur within this area, at some time of the year, include:


  • Washington ground squirrel [SE(OR)]


  • American white pelican [ST(WA)]
  • common loon [SS(WA)]
  • greater sage grouse [FC/ST(WA)]
  • ferruginous hawk [ST(WA)]
  • sandhill crane [SE(WA)]
  • yellow-billed cuckoo [FT/SE]


  • bull trout [FT]
  • chinook salmon, Fall (Snake River) [FT/ST(OR)]; Spring/Summer (Snake River) [FT/ST(OR)]; Spring (upper Columbia) [FE]
  • chum salmon (Columbia River) [FT]
  • sockeye salmon (Snake River) [FE]
  • steelhead trout (middle Columbia) [FT]; (Snake River) [FT]; (upper Columbia) [FT]


  • Northern leopard frog [SE]

Critical habitats:

These are the specific areas occupied by an endangered or threatened species that contain the physical or biological features that are essential to the conservation of that species – and that may need special management or protection. Critical habitat may also include areas that were not occupied by the species at the time of listing but are essential to its conservation.

The following species have designated critical habitat within this area.

  • bull trout

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General Resource Concerns

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  • Wetlands in this region are all freshwater and range from seasonal open marshes to forested swamps along rivers and streams. All wetland types support a diverse array of amphibian, bird, insect and fish and wildlife species.
  • Side channels and impounded areas provide feeding and resting areas for waterfowl and herons and are important rearing areas for juvenile fish.
  • Several rivers and smaller tributary streams flow into the mainstem of the Columbia River within this area. These act as important salmon migration routes and spawning areas, as well as providing rearing habitat for juvenile salmonids and resident fish species. Stream mouths are concentration areas for anadromous fish and are feeding areas for a variety of birds. Wintering waterfowl use the mainstem Columbia as well as these rivers as some of the open water associated with the lower reaches of the rivers and streams.
  • Riparian areas serve as transitional zones between the uplands and the rivers and consequently are heavily used by a variety of wildlife. They contribute to nearshore fish habitat by providing shade, cover, and food. They also play a crucial role in supporting a large diversity and abundance of songbird species as breeding, migrating, and overwintering habitat.
  • Islands provide important nesting areas for a variety of bird species, as well as habitat for a variety of mammals.
  • Numerous habitat restoration sites exist along the middle Columbia River and its tributaries. Often, significant resources have been invested in these locations to improve stream conditions specific to salmon recovery.
  • Subsurface Habitats The shallow subsurface habitats that occur within this region include:
    • Fine sediments (mud/silt/sand) – Associated with slow/still water flows. May have aquatic vegetation present.
      • Animals associated with these areas may be: salmonid and resident fishes; birds (dabbling and diving ducks); semi-aquatic mammals (muskrat, beaver, etc.); shellfish (freshwater clams); amphibians and reptiles (frogs, newts, salamanders, turtles, etc.); insects caddis flies, mayflies, dragonflies, and stoneflies). Many other animals also utilize these areas for foraging.
    • Coarse sediments (gravel/cobble) – Associated with moderate water flow. May have aquatic vegetation present.
      • Animals associated with these areas may be salmonid and resident fishes; birds (dippers, harlequin ducks); semi-aquatic mammals (muskrat, beaver, etc.); shellfish (pearlshell mussels, crayfish); amphibians and reptiles (tailed frogs, torrent salamanders; insects caddis flies, stoneflies). Many other animals also utilize these areas for foraging.
    • Bedrock – Associated with fast water with little or no deposition of loose bed materials. Aquatic vegetation not typically present.
      • Animals associated with these areas tend to be mostly cold-water (salmonid) fishes, birds (dippers, harlequin ducks), and amphibians (torrent salamanders).


  • Various salmonids (both juvenile and adults) are present in the river above the John Day Dam throughout the year. Millions of juvenile salmonids move downstream through this area and use this area for rearing and foraging as they prepare for migration to the ocean. Returning adult salmonids of various types and stocks support significant tribal and recreational fisheries.
  • Anadromous fish (other than salmon) in this region include American shad and Pacific lamprey.
  • Resident fish present year-round in the river include white sturgeon, walleye, largemouth bass, crappie, perch, bullheads, and northern pike minnow.


  • Significant waterfowl concentrations exist throughout this GRP region from fall through spring. Hundreds of thousands of geese, swans and dabbling ducks may occupy this region during peak periods. Resident and migratory waterfowl heavily utilize the islands, backwaters, wetlands and adjacent uplands of the region from fall through spring. Numerous islands in this sub-region also provide nesting habitat for resident waterfowl.
  • Bald eagles and great blue herons are nesting residents and may be found year-round throughout the region. Peregrine falcons are commonly found as winter and spring visitors. Other raptors, including burrowing owl, golden eagles, northern harrier, osprey, and prairie falcon are also found in this area.
  • Resident and migratory songbirds heavily utilize riparian habitats year-round and are susceptible to response activities that disturb riparian vegetation.
  • Mammals common to the region include managed species such as mule and whitetail deer, etc. Other mammals present include semi-aquatic species such as beaver, muskrat, river otter, mink and raccoon. Because of their habitat preferences, these latter species are vulnerable to contact with spilled oil.
  • Amphibians and reptiles are found throughout this area.

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Specific Geographic Areas of Concern – Overview

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In general, areas of concern include shorelines with natural riparian vegetation, islands, wetlands, stream mouths, and shallow backwater areas – especially those adjacent to natural shorelines. Specific areas of concern are listed below. The item number in the list corresponds to the numbered location  on the following map.

Columbia River, Lake Wallula (~RM 292-317).

  1. McNary Pool (~RM 292-296): Large waterfowl concentration area. Raptor nesting (including osprey, prairie falcon, and ferruginous hawk) in area. Salmonids and resident fish.
  2. Hat Rock and vicinity (~RM 298-301): Shallow water habitat, waterfowl, shorebird nesting and wintering areas. Salmonids and resident fish. Public recreation area (Hat Rock State Park).
  3. Van Skinner Island and vicinity (~RM 302-305): Waterfowl concentration area. Raptor nesting (including golden eagle, prairie falcon, and ferruginous hawk) in area. Salmonids and resident fish.
  4. McNary National Wildlife Refuge (~RM 314-325): Numerous islands, sloughs and wetlands along the east shore of the Columbia River, between the mouths of the Snake and Walla Walla Rivers. The refuge also extends for several miles up the Walla Walla. Salmonid and resident fish present year-round. Area provides off-channel rearing habitat for juvenile salmonids. This area supports very large numbers of waterfowl (including American white pelican [SE]), shorebirds, herons, and raptors. In addition, the riparian area supports varied wildlife including song and game birds, mule and white-tailed deer, foraging mammals. Public recreation area.
  5. Strawberry Island and vicinity, Snake River (~RM 3): Strawberry Island is Part of McNary National Wildlife. Riparian and wetland habitats. Migratory waterfowl concentration and nesting areas (including American white pelican [SE]). Great blue heron foraging area. Salmonid and resident fish present year-round.
  6. Bateman Island and vicinity (~RM 333-337) and lower Yakima River: Waterfowl and shorebird migration and wintering concentration area. Concentration and breeding areas for Western grebes [SC], and Common loons [SS] on main stem. Yakima River delta serves as a biodiversity corridor, consisting of mixed riparian, wetland, and shrub-steppe used by a variety of species. Salmonid habitat (including Bull trout [FT/SC]).
  7. Hanford Reach Islands (~RM 339-343). Waterfowl and shorebird migration, wintering, and nesting concentration area. Concentration area for American white pelican [SE]. Breeding area for Long-billed curlew. Great blue heron and Forster’s tern nesting colonies.

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Specific Geographic Areas of Concern – Maps and Descriptions

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Cultural Resources at Risk – Summary

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Culturally significant resources are present within the planning area. Information regarding the type and location of cultural resources is maintained by the Washington Department of Archeology and Historic Preservation (WDAHP). This sensitive information is made available to the Washington Department of Ecology for oil spill preparedness and response planning. The Tribal Historic Preservation Offices (THPOs) or Cultural Resource Departments of local tribes (see Table 6‑1) may also be able to provide information on cultural resources at risk in the area and should be contacted, along with WDAHP, through normal trustee notification processes when significant oil spills, or smaller spills above reportable thresholds, occur in the area.

During a spill response, after the Unified Command is established, information related to specific archeological concerns will be coordinated through the Environmental Unit. In order to ensure that tactical response strategies do not inadvertently harm culturally sensitive sites, WDAHP should be consulted before disturbing any soil or sediment during a response action, including submerged soils or sediments. WDAHP and/or the Tribal governments may assign a person, or provide a list of professional archeologists that can be contracted, to monitor response activities and cleanup operations for the protection of cultural resources at risk. Due to the sensitive nature of such information, details regarding the location and type of cultural resources present are not included in this document.

MCRM-GRP Cultural Resource Contacts

Contact Phone E-mail
Washington Department of Archaeology and Historic Preservation (360) 586-3080 Rob.Whitlam@dahp.wa.gov
Oregon State Historic Preservation Officer (503) 986-0674 Dennis.Griffin@oregon.gov
Confederated Tribes and Bands of the Yakama Nation (509) 865-5121 kate@yakama.com
Confederated Tribes of the Colville Reservation (509) 634-2695 guy.moura@colvilletribes.com
Confederated Tribes of the Umatilla Indian Reservation (541) 276-3447 tearafarrowferman@ctuir.com
Cowlitz Indian Tribe (360) 577-6962 culture@cowlitz.org
Nez Perce Tribe (208) 621-3893 keithb@nezperce.org
Confederated Tribes of Warm Springs (541) 553-2422 Holly.Shea@ctwsbnr.org

Any human remains, burial sites, or burial-related materials that are discovered during a spill response must be treated with respect at all times (photographing human remains is prohibited to all except the appropriate authorities). Refer to National Historic Preservation Act Compliance Guidelines (NWACP Section 9403) during an emergency response.

Procedures for the Discovery of Cultural Resources

If any person monitoring work activities or involved in spill response believes that they have encountered cultural resources, all workers must stop immediately and notify the Unified Command and Cultural Resource Specialist. The area of work stoppage must be adequate to provide for the security, protection, and integrity of the material or artifact(s) discovered.

Prehistoric Cultural Resources (May include, but are not limited to, any of the following items):

  • Lithic debitage (stone chips and other tool-making byproducts)
  • Flaked or ground stone tools
  • Exotic rock, minerals, or quarries
  • Concentrations of organically stained sediments, charcoal, or ash
  • Fire-modified rock
  • Rock alignments or rock structures
  • Bone (burned, modified, or in association with other bone, artifacts, or features)
  • Shell or shell fragments
  • Petroglyphs and pictographs
  • Fish weirs, fish traps, and prehistoric water craft
  • Culturally modified trees
  • Physical locations or features (traditional cultural properties)
  • Submerged villages sites or artifacts

Historic cultural material (May include any of the following items over 50 years old):

  • Bottles, or other glass
  • Cans
  • Ceramics
  • Milled wood, brick, concrete, metal, or other building material
  • Trash dumps
  • Homesteads, building remains
  • Logging, mining, or railroad features
  • Piers, wharves, docks, bridges, dams, or shipwrecks
  • Shipwrecks or other submerged historical objects

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Economic Resources at Risk – Summary

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Socio-economic sensitive resources are facilities or locations that rely on a body of water to be economically viable. Because of their location, they could be severely impacted if an oil spill were to occur. Economically sensitive resources are separated into three categories: critical infrastructure, water dependent commercial areas, and water dependent recreation areas. The appendix provides a list of economic resources for this GRP area.

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General Information

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Flight restriction zones

The Environmental Unit (Planning Section) may recommend flight restriction zones to minimize disturbance or injury to wildlife during an oil spill. Pilots/operators can decrease the risk of aircraft/bird collisions, prevent the accidental driving of wildlife into oiled areas, and minimize abandonment of nests by keeping a safe distance and altitude from these identified sensitive areas.

The Air Operations Branch (Operations Section) will manage all aircraft operations related to a response and will coordinate the establishment of any Flight Restriction Zones as appropriate. Environmental Unit staff will work with the Air Operations Branch Director to resolve any conflicts that arise between flight activities and sensitive resources.

In addition to restrictions associated with wildlife, Tribal authorities may also request notification when overflights are likely to affect culturally sensitive areas within reservations. See Oil Spill Best Management Practices (NWACP Section 9301) for more information on the use of aircraft and helicopters in open water and shoreline responses.

Wildlife Deterrence

The Wildlife Deterrence Unit within the Wildlife Branch (Operations Section) manages wildlife deterrence operations. These are actions intended to minimize injuries to wildlife by keeping animals away from the oil and cleanup operations. Deterrence activities may include using acoustic or visual deterrent devices, boats, aircraft or other tools. The Wildlife Branch works with state and federal agencies, and the Environmental Unit (Planning Section), to develop deterrence plans as appropriate.

For more information see the Northwest Wildlife Response Plan (NWACP Section 9310) and Northwest Area Wildlife Deterrence Resources (NWACP Section 9311).

Oiled Wildlife

Capturing oiled wildlife may be hazardous to both personnel and the affected animals. Incident personnel should not try to approach or capture oiled wildlife but should report any observations of oiled wildlife to the Wildlife Branch (Operations Section).

For more information see the Northwest Wildlife Response Plan (NWACP Section 9310).

Wildlife Refuges and Wilderness Areas

The following are located within this region:

  • Cold Springs National Wildlife Refuge
  • McNary National Wildlife Refug

Aquatic Invasive Species

The waters of this region may contain aquatic invasive species (AIS) – species of plants and/or animals that are not native to an area and that can be harmful to an area’s ecosystem. If so, preventative actions may be required to prevent the spread of these species as a result of spill response activities and the Environmental Unit is able to recommend operational techniques and strategies to assist with this issue.

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