Chehalis River GRP

  • Interim update: N/A
  • Last full updated: 2024
  • Public Comment:

Table of Contents


Site Description

This section provides a description of the area’s physical features, hydrology, climate and winds, and describes oil spill risks in the Chehalis River area.
The Chehalis Basin is the second-largest river basin in Washington, draining 2,700 square miles. The planning area begins on the Chehalis River, upstream of Cosmopolis at river mile (RM) 4. It follows the river southeast to the city of Chehalis (RM 70), and then west to Pe Ell (RM 110). The plan also covers the lower miles of the Chehalis tributaries, including the South Fork Chehalis River, Newaukum River, Skookumchuck River, Black River, Satsop River, and Wynoochee River, and many other creeks and streams. The lower 4 miles of the Chehalis River, from Cosmopolis to the river mouth, is included in the Grays Harbor GRP.

Open to read more

The waters of the basin drain eight counties of Washington State (Thurston, Lewis, Pacific, Cowlitz, Mason, Jefferson, Grays Harbor, and Wahkiakum) and the Confederated Tribes of the Chehalis Reservation. Along the river, in order from the mouth to the headwaters, the Chehalis passes by the communities of Cosmopolis, Central Park, Montesano, Satsop, Fuller, Elma, Malone, Porter, Oakville, Rochester, Gate, Grand Mound, Littlerock, Maytown, Tenino, Fords Prairie, Centralia, Chehalis, Adna, Curtis, Dryad, Doty and Pe Ell. The reservation of the Confederated Tribes of the Chehalis Reservation is within the Chehalis River Basin near Oakville. The planning area includes portions of the Kennedy-Goldsborough (WRIA 14), the Lower Chehalis (WRIA-22), Upper Chehalis (WRIA-23), Willapa (WRIA-24), and the Cowlitz (WRIA-26) watersheds.

^ top

Developed Areas

The largest cities in the Chehalis River planning area are Chehalis and Centralia which are located along the I-5 corridor in Lewis County. Smaller cities in the planning area include Oakville and Rochester near the Chehalis Tribe Reservation. Elma and Montesano are located along Highway 8 closer to Grays Harbor.

^ top

Tribes of the Chehalis River Planning Area

The Chehalis River planning area is within the usual and accustomed territories of a number of American Indian Tribes. The Indian reservation of The Confederated Tribes of the Chehalis Reservation is located near the City of Oakville, along the Chehalis River. Other federally recognized Tribes with access to the resources of the Chehalis River Basin may include the Quinault Indian Nation, Squaxin Island Tribe, Muckleshoot Tribe, Nisqually Tribe, the Puyallup Tribe of Indians, Confederated Tribes of the Grand Ronde, and the Shaolwater Bay Tribe.

Tribes can fill many roles during an oil spill response including full participation in Unified Command, providing resource specialists in the Environmental Unit, monitoring on-scene operations, and more. Information regarding tribal participation in a response is available on the Northwest Area Committee/Region 10 Regional Response Team website. Contact information for the tribes in this planning area can be found in the Resources at Risk section and on the Spill Response Contact Sheet of this GRP.

^ top


Physical Features

The main stem of the Chehalis River forms at the confluence of the West Fork Chehalis River and the East Fork Chehalis River in the Doty Hills area of southwest Lewis County. The river travels north, through forestland owned by the Weyerhaeuser Company, past the town of Pe Ell. Near Doty, Highway 6 follows the Chehalis River east towards the City of Chehalis. The South Fork Chehalis River joins the main stem where the river’s floodplain begins to form, south of Centralia in the Boistfort Prairie.

Open to read more

From the Boistfort Prairie area, the river continues north past the urban centers of Chehalis and Centralia on the Chehalis River’s east bank. On this reach, the Newaukum and Skookumchuck Rivers join the Chehalis River. The headwaters of these rivers begin on the western slope of the Cascade Range. Forest cover here drops to 69%, with approximately 25% of the land devoted to farming and the remaining 6% used by industry and cities. Several miles outside of the planning area, the Skookumchuck Dam provides water to a steam power plant and some flood control for the city of Centralia.

North of Centralia, along Interstate-5 (I-5), is a valley of large creek complexes, including Beaver Creek and Scatter Creek. These creeks flow through protected prairies that are unique to this part of Washington and home to many endangered species, including butterflies, gophers, toads, and birds. Salmon also use these creeks for spawning and rearing.

The area around Grand Mound, where Highway 12 splits west from I-5, is a wide, flat valley filled with a mix of farming and small communities along the river. The Black River passes along the northwest edge of this valley and is fed by a mix of creeks, as well as Black Lake in Olympia. Bordering the Black River and then Chehalis River to the northeast is the Capitol State Forest, a state-protected area with no development, used for hiking and camping. The Black River also has large wetland complexes near Rochester, with large buffers of dense riparian vegetation between agricultural fields and the river channel.

The Black River crosses under Highway 12 and empties into the Chehalis River downstream of Rochester, cutting through the middle of the Chehalis Indian Reservation. The valley downstream of Oakville becomes narrower, with the Chehalis River edging close to the steep slopes of the Capitol Forest to the east, while farms occupy the western side of the floodplain. The river in this area has changed course over the years, with side channels, oxbows, and other wetlands scattered along its banks.

In Elma, Highway 12 meets Highway 8, running east to west between Olympia and Aberdeen. The river also changes course here, from northwest to west. Cloquallum Creek, fed by Wildcat Creek and other streams drains the Black Hills and Olympic foothills. Cloquallum Creek joins the Chehalis River southeast of the City of Elma in a series of wetlands and oxbows. From here to Cosmopolis, a buffer of farms and wetlands separates the Highway 12 from the river.

West of Elma is the Satsop River, the City of Montesano, and the Wynoochee River. The headwaters of the Satsop and Wynoochee Rivers begin on the southern slope of the Olympic Range. They are the Chehalis River’s largest tributaries. The tide influences the flow of the Chehalis River from river’s mouth in Aberdeen upstream to Montesano.

Between river mile 10 near Montesano and the edge of the planning area in Cosmopolis lies the Chehalis River Surge Plain, a complex of sloughs, islands, and wetlands that is prime salmon and
waterfowl habitat. Washington Department of Natural Resources manages the majority of the Chehalis River Surge Plain. The northern riverbank in this reach includes homes, farms, and railroad properties.

The planning area ends just upstream of Cosmopolis, where the Grays Harbor GRP begins. The Chehalis River empties into Grays Harbor at the city of Aberdeen, and from there to the Pacific Ocean.

The geology of the Chehalis Basin is complex and includes three mountain ranges, Cascade Range, Olympic Range, and Coast Range (Willapa Hills and Black Hills). In the mountainous regions, volcanic and sedimentary bedrock formations shape the physical features of the watershed. Lowland areas feature glacial and alluvial sediment deposits of sand, gravel, silt, and clay. The basin features flat river valleys, open prairies, and rolling hills. Within the Chehalis Basin, the elevation varies from sea level at Grays Harbor, to the 5,054-foot summit of Capital Peak in the Olympic National Forest.

The Basin’s wide, flat topography makes it prone to flooding, but as the climate changes, catastrophic floods are occurring with greater frequency. Significant restoration projects are happening in the Chehalis Basin to restore aquatic species habitat and reduce major flood-related damage to communities and landscapes. On several occasions floodwaters have closed Interstate 5 as well as rail lines and other area highways (Ecology).

The Chehalis River watershed has unique characteristics compared to other Washington Rivers. It is the only watershed in Washington that drains water from the Cascade Range directly to the Pacific Ocean. Other Cascade Range rivers outfall to Puget Sound or the Columbia River. The headwaters of the Chehalis are lower in elevation than other rivers, making the Chehalis River flow less dependent on snow melt and glacier runoff. The Chehalis River watershed is one of the state’s only major river drainage systems with no salmon species listed as threatened or endangered. However, today’s salmon runs are reported to be as much as 80% less than historical run as a result of lost and damaged habitat, climate change, and development (Ecology).


^ top


The majority of the watershed is rain-dependent, with only the Wynoochee and Satsop Rivers having some summer impact from delayed snowmelt in the Olympic Mountains. As with the rest of Western Washington, summer is considered the dry season with precipitation dropping close to zero during the summer months. Precipitation varies throughout the Chehalis Basin. Rainfall is lowest in the prairies near Centralia, where annual precipitation averages 47 inches. Streams draining the central prairies vary considerably in width and flow depending on rainfall, sometimes running dry, other times flooding their banks into the neighbor fields and developed areas. Rainfall is highest in the Olympic Mountain, which averages 130 inches of rain annually near Wishkah River Reservoirs.

Open to read more

Most years, the Chehalis River at Porter drops below 1,000 cubic feet per second (cfs) from July through September with mean monthly discharges of 617 in July, 412 in August, and 540 in September. The rainy season usually begins in November, when the mean monthly discharge increases to 5,470 cfs at Porter. The highest mean discharge occurs in January, averaging 9,320 cfs. In the spring, river flows drop steadily through June (USGS).

Annual flooding events on the Chehalis River and its tributaries is normal. Flooding is most common from October through April when intense rainstorms inundate the region. When heavy rains are paired with warmer temperatures and snowmelt in the mountains, larger floods result. Recent floods exceeding 100-year flood levels occurred in 2022, 2009, 2007, 1996, 1990, 1986, and 1972. The December 2007 flood washed away several bridges in the upper portion of the watershed and flooded cities along the river. Some of the bridges have not been rebuilt.

Washington state, tribes, and other organizations are planning for future flooding events. Several projects are pending approval or are being implemented in the Basin to control floods and restore habitat. The Chehalis Basin Board is working to implement the Chehalis Basin Strategy, a collection of large-scale flood reduction strategies. The group’s Aquatic Species Restoration Plan proposes the protection and restoration of river and stream habitat, the correction of fish passage barriers, and the restoration of riparian and floodplain habitat (Ecology).


^ top

Climate and Winds

The climate of Chehalis River Basin is mild. Generally, temperatures are warmer in the summer and colder in the winter than Seattle and other locations farther north along Puget Sound. January is the coldest month with the average high of 45.6°F and average low of 33.5°F. July is the warmest month when the average high is 78.7°F and average lows of 51.5°F (WRCC). The area is typically frost-free for 163 to 190 days. Snow rarely accumulates except in the mountainous regions.

Open to read more

Weather in the region is often influenced by the landforms of the Chehalis Gap. The Chehalis Gap is the area of low elevation between the southern end of the Olympic Range and Willapa Hills at the foothills of Oregon’s Coast Range. The Chehalis Gap creates space for a marine push of cooler air from the Pacific Ocean that allows low clouds and fog to form overnight. Because of the Chehalis Gap, mornings often begin with gray skies. The low clouds will often lift by the afternoon as landward temperatures rise.

Winds vary throughout the region and is dependent on local topography and temperature. Prevailing winds near the coast at Hoquiam are from the west in April through September, and east in October through March (WRCC). Average annual wind speed at the Bowerman Airport in Hoquiam is 9.3 mph. The lightest winds are usually in September, with the lowest monthly average of 7.5 mph. Winds are typically strongest in January and December, at 11 mph (WRCC).

^ top

Tides and Currents

River volumes and currents become more influenced by the tide as the river reaches Grays Harbor. The lower fifteen miles of the Chehalis River is tidally influenced. In the lower reaches of the river, saltwater intrudes which may make the flows and currents in the lower river reverse. During extreme king tides there is anecdotal evidence of tidal variation as far as Porter, 30 miles upstream of the mouth. Tidal variations at Montesano range from lows of -2.4 feet in June and July to highs of 10.6 in January. High tide at Montesano occurs approximately 1.5 hours after high-tide at the entrance to Grays Harbor on the Washington Coast. The time it takes to transition to low tide is similar.

Open to read more

The area between the Newaukum and Skookumchuck rivers, known as the Chehalis Reach, has a nearly flat slope and water movement is significantly slower than in the rest of the watershed. On the main Chehalis River, flows in the upper watershed near Doty range from lows of under 100 cfs between July and September to highs of 1300 cfs in December and January. The Newaukum has similar patterns and capacity, while the Skookumchuck varies between 120 cfs in the dry season to 800 cfs in the winter. By the time the Chehalis River reaches Grand Mound, the flow is five or six times higher than it was in Doty. In Porter, with the additional waters of the Black River added, flows vary from 419 in August up to 9,500 cfs in January. The Satsop carries volumes between 330 and 4300 cfs, and the Wynoochee contributes an additional 240 to 2700 cfs. By the time the Chehalis reaches Aberdeen it has a volume of at least 1000 cfs in August up to 16,300 cfs in January. The seasonal variation of the river is intense and will have a significant impact on a spill response.

^ top

Risk Assessment

The Chehalis River Basin is plentiful in natural, cultural, and economic resources, all at risk of injury from oil spills. Potential oil spill risks include, but aren’t limited to, road transportation, rail transportation, oil pipelines, aircraft, and recreational boating. This section briefly discusses these risks and how they could impact the Chehalis River GRP planning area.

Open to read more

Oil Types: Both refined petroleum products and crude oils are transported in bulk within this planning area. Crude oil contains a mix of hydrocarbons with a wide range of properties, while a refined product is a single type of oil, such as diesel or gasoline. Depending on the oil and the characteristics of the water the oil is spilled into, some of the oil transported in this planning area may not float.

Different oils will behave differently when spilled to water. Some heavy oils will sink immediately, some oil suspends in the water column, and lighter oils may remain on the surface and evaporate within hours. Over time, oil that initially floats can weather and mix with sediment, causing it to submerge or sink. Non-floating oils pose a specific risk to the environment because they can harm underwater or bottom-dwelling species that would otherwise be unaffected during an oil spill that remained floating on the water’s surface.

Traditional response strategies, including the booming strategies in this GRP, are designed for floating oil. However, there are steps we can take to plan for and respond to a non-floating oil spill. Section 3 provides an overview of areas where non-floating oil might accumulate if spilled within this planning area, along with information on specific tactics that may be effective during a response. More response options recommended for finding and recovering oil below the water’s surface can be found in the Non-Floating Oil Spill Response Tool (NWACP Section 9412).

Road Transportation: Vehicle traffic on roadways pose an oil spill risk throughout the area. Commercial trucks can contain hundreds to thousands of gallons of fuel and oil, and almost any kind of hazardous waste or material. An accident involving a fully loaded tank truck on the various roads and highways that border the river and its tributary creeks could result in a substantial oil spill. Smaller vehicle accidents pose a similar risk, commensurate to the volume of fuel and oil they carry. Spills from vehicles onto roadways could cause fuel or oil to flow from ditches or pavement into streams, creeks, wasteways, or stormwater systems, ultimately impacting the Chehalis or other tributaries in the area.

Highway bridges, such as those on I-5 in Centralia and Chehalis and Highway 12 from Aberdeen to Centralia, pose the greatest risk of road spills due to the quantity of vehicles and speed of travel. However, accidents can also occur on smaller roads, particularly during extreme weather. In the upper watershed, logging and tanker truck accidents are the most likely source of a significant spill.

Rail Transportation: 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 Interstate-5 through the planning area.

The Port of Chehalis owns tracks that run from city of Chehalis, near the Newaukum Confluence, west along the river, crossing just past the South Fork and then slightly south into Curtis. Although historically this line ran to South Bend near Willapa Bay and was the most productive lumber rail spur in the country, the decline of the logging industry has vastly reduced rail traffic in the area. Much of the old rail grade is now the Willapa Hills Trail, maintained by the Washington State Parks and Recreation Commission.

BNSF Railway Company (BNSF) owns tracks that enter the planning area from the south in Napavine, following the Newaukum River to Chehalis. The tracks pass through Centralia, then veer east, following the Skookumchuck River up to Bucoda, north through Tenino and out of the planning area. This area is a section of a larger rail transportation corridor, which stretches between Canada to the north and Oregon to the south, generally parallel to I-5. BNSF operates a rail switchyard in Centralia where fueling operations take place. This area is at risk from trains carrying crude oil, refined oil, and other hazardous materials. BNSF maintains an oil spill contingency plan with Washington Department of Ecology.

Puget Sound and Pacific Railroad (PSAP), owned by Genesee and Wyoming, operates a line between Centralia and Hoquiam within the planning area. From Centralia, the southern spur of the line travels south of Capital State Forest towards Elma. From Elma to Hoquiam the rail line closely parallels Highway 12. PSAP transports diesel, biodiesel, glycerin crude, rapeseed oil, mineral oil, and petroleum oil to and from facilities in Hoquiam and Elma. Fueling operations occur in fueling yards in Elma and Centralia. The rail line crosses the Skookumchuck River, Black River, Satsop River, and Wynoochee River. PSAP’s northern route extends from Elma to Bangor on the western edge of Puget Sound. The railroad does not transport bulk oil on this northern spur. Diesel from locomotives and small quantities of tanker cars in mixed load trains create the largest risk in this area. The Puget Sound and Pacific Railroad maintains an oil spill contingency plan with Washington Department of Ecology.

Chehalis-Centralia Railroad & Museum (CCR&M) owns tracks that run from city of Chehalis, near the Newaukum Confluence to the town of Curtis. The rail line follows the right bank of the Chehalis upriver crossing the South Fork Chehalis just prior to the end of the line. CCR&M operates seasonal excursion trains, offering both coach and dinner train service. The train is powered by a steam-powered logging locomotive that was built in 1916.

Oil Pipelines: Olympic Pipeline, operated by BP Pipelines North America, consists of over 400 miles of petroleum product pipelines. The pipelines extend from refineries in Northwest Washington and runs parallel to Puget Sound and I-5 to Portland, Oregon. The pipeline transports various grades of unleaded gasoline, aviation turbine fuel (kerosene), and diesel fuel. It delivers fuel to Harbor Island in Seattle, Seattle-Tacoma International Airport, Renton, Tacoma, Vancouver Washington, and Portland, Oregon. No delivery sites or pumping stations are within the Chehalis River GRP boundary and the pipeline does not directly cross the Chehalis River. It does cross several tributaries, specifically the Newaukum River, Berwick Creek, Dillenbaugh Creek, Salzer Creek, Hanaford Creek and the Skookumchuck River, in addition to smaller creeks and streams. If the pipeline were to leak or rupture, impacts to sensitive resources in the area could be significant due to the volume of product. Olympic Pipeline maintains an oil spill contingency plan with Washington State Department of Ecology.

Aircraft: The Chehalis-Centralia Airport handles 48,000 annual operations and is bordered by the Chehalis River on two sides, with a gap of less than a half-mile between the runway and the water. Elma Municipal Airport handles 12,000 annual operations and is also within a half-mile of the river, and less than 1,000 feet from a tributary. There is always a potential for aircraft failures during inbound and outbound flights that could result in fuel releases to water.

Recreational and Commercial Boating: Accidents involving recreational watercraft on the Chehalis could result in spills between a few gallons to several dozen gallons of fuel oil. Accidents could include a vessel grounding, fire, sinking, or explosion. Oil to water from bilge discharges and fueling spills are the most common incident types. Most commercial boat traffic ends downstream of the planning area, but commercial barges can travel upstream to at least RM 15, past Montesano. The Chehalis is considered a navigable waterway up to mile 68 in Centralia. Recreational vessels upstream of the Newaukum River confluence tend to be hand-launched rafts, canoes, or kayaks.

Other Spill Risks: Other potential oil spill risks in the area include 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/stream banks.

^ top

Resources at Risk

This section provides a summary of natural, cultural, and economic resources at risk in the vicinity of the Chehalis River, 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 table of contents.

Open to read more

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.

^ top

Natural Resources at Risk – Summary

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 other operations such as cleanup, reconnaissance, or fire suppression activities. Some of the
bird species are resident throughout the year, but many others seasonally migrate through the area.

Open to read more

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:

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

Federal and State listed species that may occur within this area include:


  • marbled murrelet [FT/SE]
  • northern spotted owl [FT/SE]
  • yellow billed cuckoo [FT/SE]


  • fisher [FC/SE]
  • pocket gopher (Olympia, Tenino, Yelm) [FT/ST]
  • western gray squirrel [ST]


  • bull trout [FT]
  • eulachon [FT]
  • Olympic mudminnow [SS]
  • green sturgeon [FT]


  • Oregon spotted frog [FT/SE]


  • Mardon skipper [SE]
  • Taylor’s checkerspot [FE/SE]


  • golden paintbrush [FT]
  • Kincaid’s lupine [FT]
  • water howellia [FT]

Critical habitats are the specific areas, occupied by an endangered or threatened species at the time it was listed, 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 federally designated critical habitats within this area:

  • bull trout
  • green sturgeon
  • Kincaid’s lupine
  • marbled murrelet
  • Oregon spotted frog
  • pocket gopher (Yelm)
  • Taylor’s checkerspot

^ top

General Resource Concerns


  • Wetlands in the lower reaches of this region are freshwater although tidally influenced. These wetlands range from seasonal open marshes to forested swamps along rivers and streams. All wetland types support a diverse array of amphibian, bird, insect, fish, and wildlife species.
Open to read more
  • Rivers and streams throughout this region provide spawning and rearing habitat forvarious salmonid species. The associated riparian scrub and woodlands play acrucial role in supporting wildlife and a large diversity and abundance of songbird bird species as breeding, migrating, and overwintering habitat. Stream mouths are concentration areas for fish and are feeding areas for a variety of birds.
  • Side channels and impounded areas provide feeding and resting areas for waterfowl and herons and are important rearing areas for juvenile fish.
  • Islands provide important nesting habitat for a variety of bird species, as well as habitat for a variety of mammals. Typical resident fish are likely present in most streams.
  • The native prairie habitat present in this region, primarily in the vicinity of the Scatter Creek Wildlife Area, is extremely rare and sensitive to disturbance. These areas support a wide variety of wildlife including listed species such as the Mardon skipper [SE] and Taylor’s checkerspot [FE/SE] butterflies, and the Mazama pocket gopher [FT/SE].
  • Shallow subsurface habitats occur throughout the drainage that serves the Chehalis River and all its associated tributaries.
    • Fine sediments (mud/silt/sand) – Associated with slow/still water flows. May have aquatic vegetation present.
      Animals associated with these areas tend to be: cold and/or warm water fish; birds (dabbling ducks and geese); 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 tend to be: miscellaneous cold (salmonid) and/or warm (bass, crappie, etc) water fish; 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 present.
      Animals associated with these areas tend to be mostly cold-water fishes, birds (dippers, harlequin ducks), and amphibians (torrent salamanders).

Fish and Shellfish:

  • Anadromous fish, including salmonids species are present throughout the basin, including bull trout [FT], coho, chinook, chum, steelhead, and coastal cutthroat. Pacific lamprey and eulachon [FT] are also present in the river system. Sturgeon (white and green [FT]) may also be present in the lower Chehalis.
  • Various resident fish species are present in area rivers including largemouth bass, northern pike minnow, Olympic mud minnow [SS], lamprey, perch, dace, rainbow, resident cutthroat, sculpin, and perch.
  • Freshwater mussels are found throughout most of the region.


  • Wintering waterfowl concentrations, (primarily ducks, geese, and swans) are present along the main stem of the Chehalis and adjoining lowlands. Field size, flood
    conditions, weather, and crop rotations of any given year help to determine the actual waterfowl distribution.
  • Migratory and overwintering shorebirds utilize the protected waters and marshlands of the lower Chehalis River during their stopovers.
  • Great blue and green herons, along with raptors (including bald eagle, osprey and peregrine falcon) nest and forage year-round along waterways throughout the region.
  • 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 semi-aquatic species such as beaver, muskrat, river otter, mink and raccoon. These small mammals are vulnerable to contact with spilled oil because of their habitat preferences. Western gray squirrel [ST] and Mazama pocket gopher [FT/ST] presence is documented at locations throughout the drainage. Larger mammals (deer, elk, etc.) are also present throughout this area. Seals and sea lions found on the mainstem of the Chehalis River.

Tributary descriptions within the GRP:

  • Wynoochee River (Chehalis ~RM 13). Bald eagle nesting ~ Wynoochee RM 10. Harlequin duck breeding area upstream from about RM 5. Waterfowl concentration between RM 0 and RM 1. Salmonid presence includes coho, fall chinook, fall chum, summer/ winter steelhead, coastal/resident cutthroat. Olympic mudminnow [SS] and typical resident fish present.
  • Satsop River (Chehalis ~RM 20). Waterfowl concentrations from mouth to ~ Satsop RM 6. Salmonid presence includes coho, fall chum, summer/fall chinook, winter steelhead, coastal cutthroat. Olympic mudminnow [SS] and typical resident fish present.
  • Black River (Chehalis ~RM 47). Waterfowl concentrations and raptors (bald eagle and osprey) nesting near mouth of the river. Harlequin breeding habitat throughout this drainage. Western gray squirrel [ST] detected throughout the reach. Salmonid presence includes coho, fall chinook, winter steelhead, fall chum, coastal/resident cutthroat trout. Olympic mudminnow [SS] documented in small tributaries. Typical resident fish presence. Tribal lands south of river in lower reach. Black River Management Area located ~ Black River RM 11.
  • Scatter Creek (Chehalis ~RM 55). Wood duck breeding throughout the reach. Extensive Mazama pocket gopher [FT/ST] presence throughout this area. Salmonid presence includes coho, fall chinook, coastal/resident cutthroat trout. Typical resident fish present. Scatter Creek Wildlife Area located ~RM 5-7. There is extensive presence of Mardon skipper [SE] and Taylor’s checkerspot [FE/SE] butterflies near the City of Tenino.
  • Lincoln Creek (Chehalis ~RM 62). Elk winter range. Western gray squirrel [ST] documented in vicinity of ~ Lincoln Creek RM 3.5. Salmonid presence includes coho, winter steelhead, and coastal cutthroat trout.
  • Skookumchuck River (Chehalis ~RM 67). Waterfowl concentration at mouth of river. Additional waterfowl concentration (associated with agricultural lands) and extensive harlequin duck breeding area above ~RM 4.5. Purple martin [SC] and Vaux’s swift [SC] near the mouth of the river. Salmonid presence includes coho, spring/fall chinook, winter steelhead, coastal/resident cutthroat trout. Olympic mudminnow [SS] documented in small tributaries. Typical resident fish present. WDFW game farm with extensive riparian habitat located near river mouth.
  • Hanaford Creek (Skookumchuck ~RM 4). – Includes portions of North Hanaford Creek and South Hanaford Creek. Elk winter range. Salmonid presence includes coho, winter steelhead, coastal/resident cutthroat trout. Olympic mudminnow [SS] presence is documented. Typical resident fish present.
  • Newaukum River (Chehalis ~RM 75). Bald eagle nesting ~ RM 6. Waterfowl concentrations near the mouth of river. Salmonid presence includes coho, spring/fall chinook, winter steelhead, coastal/resident cutthroat. Olympic mudminnow [SS] documented and is likely to occur in small tributaries and oxbow lakes.
  • South Fork Chehalis River (Chehalis ~RM 88). Bald eagle nesting near RM 5. Extensive elk winter range. Olympic mudminnow [SS] presence documented. Salmonid presence includes coho, spring/fall chinook, winter steelhead, coastal/resident cutthroat trout.

^ top

Specific Geographic Areas of Concern – Overview

  1. Ferbrache Unit, Chehalis Wildlife Area at mouth of Wynoochee River (~ Chehalis RM 13): Waterfowl concentration area. Bald eagle nesting. Salmonid spawning and rearing habitat. Resident fish include Olympic mudminnow [SS].
Open to read more
  1. Ferbrache Unit, Chehalis Wildlife Area (~ Chehalis RM 18): Unit is 114 acres, located five miles southeast of Montesano. Maintained for wintering waterfowl forage, fishing access and a pheasant release site for fall hunting. Raptors, shorebirds, herons, and upland game birds also present. Deer, elk, and small mammal presence.
  2. Satsop Unit, Chehalis Wildlife Area, (~ Chehalis RM 20): The unit is 1,432 acres near the confluence of the Satsop River and the Chehalis River. This unit is maintained as floodplain habitat. General waterfowl concentration area. Salmonid spawning and rearing habitat. Resident fish include Olympic mudminnow [SS]. Bald eagle nesting. Other raptors, shorebirds, herons, and upland game birds also present. Deer, elk, and small mammal presence.
  3. Chehalis Wildlife Area, (~ Chehalis RM 22): This area is 531 acres located southwest of Elma. General waterfowl concentration area. The unit is maintained for waterfowl habitat and associated recreation. Wood duck nesting/brooding and significant shorebird usage (vicinity of Wenzel Slough/Vance Creek Park). Primarily open wetland, riparian shrub habitat, or meadow/field habitat. Bald eagle nesting. Other wildlife species known to exist in the area include the Olympic mudminnow [SS], mink, shorebirds, wood duck, waterfowl, trumpeter swan, and osprey.
  4. Hoxit Unit, Chehalis Wildlife Area, (~ Chehalis RM 34-37): This 80-acre unit is located 6.5 miles south of the town of Elma and is maintained for winter waterfowl habitat. Bald eagle nesting. Other raptors, shorebirds, herons, and upland game birds also present. Deer, elk, and small mammal presence.
  5. Davis Creek, Scatter Creek Wildlife Area (~ Chehalis RM 41-43): Approximately 500 acres located just outside of the town of Oakville, near State Hwy 12. Most of the land is characterized as open wetland, riparian shrub habitat, meadow/field habitat, and oak woodland. Waterfowl concentration area. Trumpeter swans, and a variety of salmon species are present. Other species known to exist in the area include Olympic mud minnows [SS], mink, shorebirds, elk, deer, fox, coyote, bobcat, and grouse.
  6. Mouth of Black River (~ Chehalis RM 47): Waterfowl concentrations, bald eagle and osprey nesting near mouth of the river. Harlequin breeding habitat throughout this drainage. Western gray squirrel [ST] presence throughout the reach. Salmonid spawning and rearing habitat. Olympic mudminnow [SS] documented in small tributaries. Tribal lands.
  7. Mouth of Scatter Creek (~ Chehalis RM 55): Waterfowl concentration and wood duck nesting area. Extensive Mazama pocket gopher [FT/ST] presence throughout this area. Salmonid spawning and rearing habitat.
  8. Scatter Creek Wildlife Area. Prairie habitat supporting golden paintbrush [FT], numerous butterfly species, including Mardon skipper [SE] and Taylor’s checkerspot [FE/SE] with Critical Habitat. Mazama pocket gopher [FT/ST] presence. Osprey nesting. Salmonid spawning and rearing habitat.
  9. Chehalis wetland complex, mouth of Skookumchuck River (~ Chehalis RM 67): Scrub shrub and emergent wetlands support large concentrations of wintering waterfowl, cavity nesting ducks, and Canada goose nesting. Extensive harlequin duck breeding area. Salmonid spawning and rearing habitat. Resident fish include Olympic mudminnow [SS]. WDFW game farm.
  10. Chehalis wetlands complex, mouth of the Newaukum River (~ Chehalis RM 75): Waterfowl concentrations. Scrub shrub and emergent wetlands support large concentrations of wintering waterfowl, cavity nesting ducks, and Canada goose nesting. Bald eagle nesting area. Salmonid spawning and rearing habitat. Resident fish include Olympic mudminnow [SS].

^ top

Specific Geographic Areas of Concern – Maps and Descriptions


Figure 1: Chehalis Basin Geographic Areas of Concern. 1) Ferbrache Unit, Chehalis Wildlife Area; 2) Ferbache Unit, Chehalis Wildlife Area; 3) Satsop Unit, Chehalis Wildlife Area; 4) Chehalis Wildlife Area

Open to read more

Figure 2: Chehalis Basin Geographic Areas of Concern. 5) Hoxit Unit, Chehalis Wildlife Area; 6) Davis Creek, Scatter Creek Wildlife Area; 7) Mouth of Black River; 8) Mouth of Scatter Creek; 9) Scatter Creek Wildlife Area.

Figure 3: Chehalis Basin Geographic Areas of Concern. 10) Chehalis wetland complex, mouth of Skookumchuck River; 11) Chehalis wetland complex, mouth of Newaukum River.

^ top

Cultural Resources at Risk – Summary

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.

Open to read more

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. 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.

Table 6-1: CHER-GRP Cultural Resource Contacts

Contact Phone Email
WDAHP 360-586-3080
Chehalis Confederated Tribes, THPO 360‐709‐1747
Quinault Indian Nation 360‐276‐8215 x 520
Squaxin Island Tribe, THPO 360-432-3850
Muckleshoot Tribe 253-261-4724
Nisqually Tribe 360-456-5221
Puyallup Tribe of Indians 253-573-7986
Confederated Tribes of the Grand Ronde, TPHO 503-879-2084
Shaolwater Bay Tribe 360-267-0731

Discovery of Human Skeletal Remains

The finding of human skeletal remains will be reported to the county medical examiner/coroner and local law enforcement in the most expeditious manner possible. The remains will not be touched, moved, or further disturbed. The county medical examiner/coroner will assume jurisdiction over the human skeletal remains and make a determination of whether those remains are forensic or non-forensic. If the county medical examiner/coroner determines the remains are non-forensic, then they will report that finding to the Department of Archaeology and Historic Preservation (DAHP) who will then take jurisdiction over the remains. The DAHP will notify any appropriate cemeteries and all affected tribes of the find. The State Physical Anthropologist will make a determination of whether the remains are Indian or Non-Indian and report that finding to any appropriate cemeteries and the affected tribes. The DAHP will then handle all consultation with the affected parties as to the future preservation, excavation, and disposition of the remains.

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 (NWRCP 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 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 watercraft
  • Culturally modified trees
  • Physical locations or features (traditional cultural properties)

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


^ top

Economic Resources at Risk – Summary

Tribal and commercial salmon fisheries and recreational fisheries targeting species such as salmon and steelhead are important to area and local economies.

Fish management facilities in this area include:

  • Chehalis Tribal Fish Hatchery (Oakville)
  • WDFW Skookumchuck Dam facility (Tenino)
  • WDFW Chehalis smolt/scoop trap (Independence)
  • WDFW Elk Creek fishway (Doty)

^ top

General Information

Flight restriction zones: Flight restriction zones may be recommended by the Environmental Unit (Planning Section), in consultation with the Wildlife Branch, for the purpose of reducing disturbances that could result in injury to wildlife during an oil spill. By keeping a safe distance or altitude from identified sensitive areas, pilots/operators can lessen the risk of aircraft/bird collisions, prevent the accidental hazing of wildlife into oiled areas, and avoid causing the abandonment of nests.

Implementation of Flight Restriction Zones will take place within the Air Operations Branch (Operations Section) after the Unified Command is formed. The Planning Section’s Environmental Unit will work with the Air Ops Branch Director to resolve any potential conflicts with flight activities that are essential to the spill response effort. Typically, the area within a 1,500-foot radius and below 1,000 feet in altitude is restricted to flying in areas that have been identified as sensitive; however, some areas have more restrictive zones. 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.

Open to read more

Wildlife Deterrence: The Wildlife Branch (Operations Section), in consultation with the appropriate trustee agencies and the Environmental Unit, will evaluate wildlife deterrent options for the purpose of keeping wildlife away from oil and cleanup operations and will manage any such activities during a response. Deterrence options might include the use of acoustic or visual deterrent devices, boats, aircraft or other situation-appropriate tools. For more information see the Northwest Wildlife Response Plan (NWACP Section 9310) and Northwest Area Wildlife Deterrence Resources (NWACP Section 9311).

Oiled Wildlife: Attempting to capture oiled wildlife can be hazardous to both personnel and the affected animals. Response personnel should not approach or attempt to recover oiled wildlife. Responders should report their observations of oiled wildlife to the Wildlife Branch so appropriate action can be taken. Information provided should include the location, date, and time of the sighting, and the estimated number and kind of animals observed. Early on in the response, before a Unified Command is established, oiled wildlife sightings should be reported to Washington Emergency Management Division. For more information see the Northwest Wildlife Response Plan (NWACP Section 9310).

Wildlife Areas: There are no federally designated wilderness areas present in this GRP region.

Aquatic Invasive Species: The waters of this region are known to 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. Preventative actions will be required to prevent the spread of these species as a result of spill response activities. The Environmental Unit can recommend operational techniques and strategies to assist with this issue.


^ top