Cultural Features

The Snake River is rich in archaeological resources. Evidence shows that the Columbia Plateau was inhabited as early as 11,500 years ago, and that settlements were established as early as 11,230 years ago. The Snake and Columbia Rivers were part of a transportation and trade network that extended along the entire Pacific Coast and inland to the Great Plains. Numerous archaeological sites along the Snake River are listed on the National Register of Historic Places and numerous other sites are known, including villages, fishing sites, temporary camps, storage pits, burials, shell middens, and rock art such as pictographs and petroglyphs.

Europeans and Americans began exploring and trading in the Pacific Northwest in the 18th century with trade items being transported into the Snake River Basin during that period. First contact occurred in the region in 1805 when the Lewis and Clark Expedition traveled down the Snake and into the Columbia River. Other expeditions of exploration soon followed, and trading operations were established. The Northwest Company built Fort Nez Perce in 1818 near the mouth of the Walla Walla River on the Columbia. Missionaries arrived in the 1830s and were followed by settlers in the 1840s.

From the mid to late 1800’s, numerous settlements were established along both the Columbia and Snake Rivers. Gold was discovered near Fort Colville in 1855 prompting an influx of miners. With traders, farmers, ranchers, and miners arriving in the area, steamboats began navigating the Snake River in the 1860s. Steamboats traversed over 60 sets of rapids in the free-flowing river when traveling between Pasco, Washington and Lewiston, Idaho. The USACE started modifying the Columbia River to aid vessel navigation as early as 1873 by removing obstructions; from 1876 to 1915 canals were built. The first dam was constructed on the Snake River in 1901. Between the 1950’s-1980’s, the USACE started the Lower Snake River Project with the construction of four dams in eastern Washington, bringing the total number of dams on the Snake River to 15. (USACE, Lower Snake River Dams)

Shoreline Description

Shoreline habitats along this section of the Snake River 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 (Shoreline Countermeasures Manual).

Dams & Irrigation

Human activity has had a major impact on the Snake River. The U.S. Army Corps of Engineers (USACE) has shaped the Snake River into its current form through the construction of dams; structures designed to provide irrigation water, hydroelectricity, flood control, and improved navigation. The four dams in the Lower Snake River Project were built primarily to create a navigable channel from the mouth of the Snake River to the beginning of Hells Canyon, located downstream of Lewiston, Idaho near the borders of eastern Washington, eastern Oregon, and western Idaho. The Lower Snake River dams, from upstream to downstream, include: Lower Granite Lock and Dam, Little Goose Lock and Dam, Lower Monumental Lock and Dam, and Ice Harbor Lock and Dam.

Superfund Sites & Other Historic Pollution Sites

None noted in this area.

Socio-economic Features

Large Scale Restoration Sites

None noted in this area.

Fishing & Sustenance

The Snake River once hosted some of the largest runs of various types of salmon on the continent. Sadly, this is no longer the case as most species of salmon and steelhead in the Snake River are now threatened or endangered. Harvesting salmon plays a central role in the cultures of numerous Tribes in the area. Restoration of these salmon runs is of vital importance to Tribes and various state and federal agencies overseeing the resources of the area.

Recreation & Tourism

The spectacular beauty of the Snake River Gorge attracts tourists and provides a wealth of recreational opportunities including camping, hiking, fishing, hunting, mountain biking, and recreational boating. Public recreation areas which include boat launches are located at Offield Landing, Wawawai Landing, Blyton Landing, Nisqually John Landing, Chief Timothy Park, and Greenbelt Ramp. Camping spots can also be found at most of these locations. The Snake River also hosts small inland cruise ships, which can be seen transiting to Clarkston/Lewiston and back while making stops along the way.

In addition to the recreational opportunities listed above, the USACE maintains four Habitat Management Units (HMU’s) located along the shore in this GRP area. HMU’s provide habitat for wildlife as well as fishing, hunting, and hiking opportunities for the public (USACE HMU’s).

Economic Drivers

Due to the USACE Lock and Dam system, the Snake River functions as an industrial transportation corridor, with barges transiting from the confluence with the Columbia River to Lewiston, Idaho and back. The Columbia and Snake River corridor provides a route for the transport of agricultural products from farms in the interior of the country to the Columbia River’s gateway at the Pacific Ocean. This corridor is the number one export route in the nation for wheat, and number two for corn and soybeans (Columbia Snake River System Facts). Wood products and petroleum products are also shipped by barge on the river. Additionally, the four Snake River dams produce electricity for the region. The Snake River corridor is also used as a route for rail traffic. The Great Northwest Railroad owns the commercial rail track in this planning area. The track runs parallel to the river on the north bank (river right) throughout the Snake River Lower Granite Pool. The Great Northwest Railroad operates manifest trains in this area. Manifest trains include a mix of non-oil merchandise cars, and one or more 714-barrel (29,998 gallon) capacity USDOT-approved tank cars carrying diesel.

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The Snake River is the largest tributary of the Columbia River and the 13th longest river in the United States. It originates in Yellowstone National Park and extends approximately 1080 miles to its confluence with the Columbia River. The Lower Granite Pool is approximately 40 miles in length from the top of the Lower Granite Dam to its eastern end near Lewiston, Idaho. The pool has a surface area of 8900 acres. The Lower Granite Dam, which creates Lower Granite Lake, is 3,200 feet long and about 100 feet tall. The elevation of Lower Granite Lake during normal dam operations ranges between 733 and 738 feet. The maximum pool elevation at the dam is 746.5 feet. Prior to the construction of the dams the maximum unregulated historical peak discharge was 409,000 cubic feet per second (cfs), which occurred in 1894. Currently, the average annual flow of the Snake River, based on streamflow data near Clarkston, Washington is approximately 50,300 cfs. Several organizations, such as the US Geologic Survey, maintain stream gages on the watercourses in this planning area. Please visit the USGS National Water Information System for current flow conditions.

Most of the flow into the Lower Granite Pool comes from the Snake River. Tributary streams entering the pool include Dry Creek, Alpowa Creek, Steptoe Creek, Pewawai Creek, Thorn Thicket Creek, and numerous unnamed creeks. The Lower Granite Pool is very lake-like, with dam-controlled outflow rates. The lowest flow rates typically occur during the late summer, autumn, and winter months. Higher flows occur during the spring snow melt. The upper reach of the reservoir attains higher flows than the lower reach, especially during spring runoff. Nearer to the Lower Granite Dam, the current is practically nonexistent, except for the area in front of the spillway and powerhouse, which may have strong currents and undertows that are very dangerous.

The planning area is located within Water Resource Inventory Areas Palouse (WRIA 34), and Middle Snake (WRIA 35).

Palouse (WRIA 34): The Palouse River Watershed occupies approximately 1,755,000 acres in eastern Washington. The Palouse River originates in the mountains northeast of Moscow, Idaho, and flows westerly through rolling farm and rangeland before joining the Snake River at the Whitman/Franklin County line. There are no major man-made impoundments, allowing the river to flow freely. Approximately 6 miles from the river’s confluence with the Snake River, the Palouse River drops approximately 185 feet into a deep canyon at Palouse Falls. The Palouse Falls are a natural barrier to fish passage, isolating the upper reaches of the Palouse River from the anadromous salmonids and other aquatic life in the Snake River system. The western part of the watershed is the driest, receiving as little as 10 inches of precipitation annually. Precipitation is light during summer, increasing in fall to peak during the winter months. Average flows near the mouth of the Palouse River range from 1,800 cfs in March to 300 cfs in August (Palouse Watershed Plan

Middle Snake (WRIA 35): The Middle Snake Watershed, in Water Resource Inventory Area (WRIA) 35 is located in the extreme southeast corner of Washington. WRIA 35 is bordered by the state of Oregon to the south, the state of Idaho to the east, the Palouse Watershed (WRIA 34) to the north, and the Walla Walla (WRIA 32) and Lower Snake (WRIA 33) Watersheds to the west. The basin drains approximately 2,250 square miles within the state of Washington. The Middle Snake Watershed encompasses portions of Asotin, Whitman, Garfield, and Columbia Counties within Washington. Diamond Peak, located in the Blue Mountains at the headwaters of the Tucannon River, is the highest point in the basin with an elevation of 6,380 feet. The confluence of the Snake and Tucannon Rivers is the lowest point at approximately 540 feet. The Middle Snake Watershed is semi-arid. Average annual precipitation ranges from 5 to 10 inches in the lowlands along the Snake River up to 45 inches in the peaks of the Blue Mountains. Historically, the Middle Snake Watershed habitat was prairie, canyon grasslands, and shrub-steppe vegetation. Today, much of the land in the WRIA has been converted to crop and livestock production. Non-irrigated row crops, primarily wheat, and grass-forb plant communities comprise the majority (67%) of vegetative cover in the watershed. Coniferous forests cover approximately 20%; a mixture of shrubs and trees covers 7% (WA Ecology, 2015).

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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.

Natural Resources at Risk Summary

This area contains a wide variety of aquatic, riparian, and upland habitats. These habitats support many of Washington’s anadromous salmonid species as well as a complex diversity of other wildlife including mammals, birds, and amphibians. Due to their life histories and/or behaviors, some of these species are unlikely to be 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 outside the basin. Several of the species found in this area are classified as threatened or endangered under the Federal Endangered Species Act or Washington State guidelines.

Classification types are:

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

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

Birds:

• American white pelican [SS]
• Common loon [SS]
• Ferruginous hawk [ST]
• Yellow-billed cuckoo [FT/SE]

Mammals:

• Gray Wolf [SE]

Fish:

• Bull trout [FT]
• Chinook [FT]
• Sockeye [FE]
• Steelhead [FT]

Insects:

• Monarch butterfly [FC]

Plants:

• Spalding’s catchfly [FT]

Critical habitats 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.

Critical Habitats for the following species have been federally designated within this area:

• Bull trout
• Chinook
• Steelhead
• Sockeye

General Resource Concerns

Habitats:

Wetlands in this region include areas along the main stem of the Snake River. All wetland types support a diverse array of bird, insect, fish, and wildlife species.

Islands provide important nesting habitat for a variety of bird species, as well as habitat for a variety of mammals. Gravel bars provide spawning habitat for Chinook salmon.

Stream mouths are concentration areas for anadromous fish. These areas also serve as feeding areas for a variety of birds including American white pelican.

Riparian vegetation is heavily used by a variety of wildlife and may also improve nearshore fish habitat. Riparian scrub and woodlands support a disproportionately high diversity and abundance of birds that depend on this habitat for nesting and rearing young, as well as for forage and cover during migration and overwintering.

Human-made structures such as pilings and rock jetties may be used as roosting or nesting areas for a variety of birds.

Cliffs, bluffs, and rock outcroppings provide roosting or nesting habitat for various birds of prey, upland birds, and bats.

The riverbed habitats in this area consist primarily of soft sediments, such as clay, mud, sand, and gravel and support a variety of aquatic, semi-aquatic, and bottom dwelling organisms such as the invertebrate larvae of insects (caddis flies, mayflies, and dragonflies and stoneflies), snails and freshwater mussels, and crayfish. Many species of amphibians and bottom-dwelling fish also rely on this habitat, as do other animals that forage there. This entire stretch of the Snake River is Critical Habitat for sockeye, chinook, steelhead, and bull trout. The benthic habitats in streams and rivers may include freshwater mussels and immature lamprey.

Fish:

Salmonids (including Chinook, sockeye, cutthroat trout, steelhead, and bull trout) are present in the river system throughout the year. Juvenile salmonids use backwaters, nearshore areas, and protected bays as rearing and foraging areas prior to migration into the ocean. Returning adult salmonids support tribal, commercial, and recreational fisheries.

In addition to salmonids, several other species of freshwater fish(including bass, crappie, catfish, suckers, and white sturgeon) are present within this reach of the Snake River. These species all contribute to recreational fisheries and provide important contributions to stream ecology.

Freshwater mussels are present within this general area.

Wildlife:

Bald eagles, osprey, and great blue herons are nesting residents and may be found year-round throughout the region.

Peregrine falcons, golden eagles nest in the region as do prairie falcons and Swainson’s hawks.

American white pelicans are known to occur in small groups near the mouth of the Snake River during spring and fall migrations and may also be present along other parts of the river.

Migratory and wintering waterfowl and shorebirds – Large concentrations occur throughout this entire reach of the Snake River particularly fall through spring. Hundreds to thousands of geese and dabbling ducks may occupy this region during this period. Both resident and migratory waterfowl heavily utilize the islands, backwaters, wetlands, and adjacent uplands of the region from fall through spring. The islands in this region also provide nesting habitat for resident waterfowl.

Resident and migratory songbirds heavily utilize riparian habitats year-round and are susceptible to oiling or oil ingestion if riparian vegetation and shorelines become contaminated and are vulnerable to disturbance from response activities during the nesting season.

Mammals common to the reach include deer and elk, bats, and various semi-aquatic species such as muskrat, beaver, river otter, etc.  Semi-aquatic mammals are largely dependent on riverine areas, ponds, tributaries, and riparian forests for den sites and foraging areas.

Specific Geographic Areas of Concern

In an effort to improve habitat, the United States Army Corps of Engineers established numerous Habitat Management Units (HMUs) along the Snake River. The size and complexity of these HMUs varies, but many of them include irrigation, tree and shrub plantings, food plots, nesting and brooding cover, brush piles, and nesting structures that attract wildlife. Other significant wildlife areas, in addition to those habitats provided by HMUs, include shorelines with natural riparian vegetation, islands, wetlands, stream and river mouths (both free-flowing and impounded), and shallow backwater areas – especially adjacent to natural shorelines.  Public parks, private lands, and recreational areas surround the river. Specific areas of concern are listed below and depicted on the maps near the end of this section. The number that precedes the area name in the list (below) relates to the numbered area on the map.

Figure 1

1) Offield Landing (~RM 108, south): Approximately 10 acres; camping, boating and public day-use area administered by the US Army Corp of Engineers. Steelhead spawning and waterfowl concentrations. Shrub-steppe and riparian habitat.

2) Wawawai County Park (~RM 110.5, north): Approximately 68 acres; camping and public day-use area administered by Whitman County. Steelhead, waterfowl, and amphibian presence. Shrub-steppe and riparian habitat. Known locations of Spalding’s catchfly in Palouse grasslands southeast of Park.

3) Knoxway Bay (~RM 116): Steelhead spawning and waterfowl concentrations. Freshwater mussel presence. Shrub-steppe and riparian habitat. Known locations of Spalding’s catchfly in Palouse grasslands north of river.

Figure 2

4) Steptoe Creek (~RM 128): Steelhead presence and waterfowl concentration. Shrub and riparian habitat.

5) Chief Timothy Park (~RM 132, south): Approximately 198 acres; camping, boating, and public day-use area administered by Northwest Land Management. Waterfowl concentrations. Osprey and heron nesting.

6) Chief Timothy Habitat Management Unit (~RM 132, south): Approximately 72 acres; hunting fishing and public day-use area administered by the US Army Corp of Engineers. Waterfowl concentrations. Shrub, wetland, slough and riparian habitat.

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General information

Sites Recommended for alternative shoreline protection

The following sites have identified sensitive resources, but traditional booming strategies may not be effective or practical in most circumstances. Alternative options, such as sorbent, enhanced on-water skimming nearby, or other strategies should be considered for these sites.

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 (NWRCP 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 (NWRCP Section 9310) and Northwest Area Wildlife Deterrence Resources (NWRCP 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 (NWRCP Section 9310).

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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