The Columbia River
is the largest river
in the Pacific
region of North America
rises in the Rocky Mountains in British
Columbia, Canada, flows
northwest and then south into the U.S.
state of Washington, then turns west to form most of the border between
Washington and the state of Oregon before
emptying into the Pacific
The river is long, and its largest
tributary is the Snake River
drainage basin is roughly the size of
France and extends into seven U.S. states and a Canadian
By volume, the Columbia is the fourth-largest river in the U.S.,
and it has the greatest flow of any North American river draining
into the Pacific. The river's heavy flow and its relatively steep
gradient give it tremendous potential for the generation of
electricity. The 14 hydroelectric
on the Columbia's main stem
many more on its tributaries produce more hydroelectric power
than those of any
other North American river.
The Columbia and its tributaries have been central to the region's
culture and economy for thousands of years. They have been used for
transportation since ancient times, linking the many cultural
groups of the region. The river system hosts many species of
fish, which migrate between
habitats and the saline
Pacific Ocean. These fish—especially the
species—provided the core subsistence
for natives; in past centuries, traders from across western North
America traveled to the Columbia to trade for fish.
In the late 18th century, a private American ship became the
first to enter the river from the Pacific Ocean; it was followed by
a British explorer, who navigated past the Oregon Coast Range
into the Willamette Valley
. In the following
decades, fur trading
companies used the
Columbia as a key transportation route. Overland explorers
entered the Willamette Valley through the scenic and treacherous
Gorge, and pioneers began to settle the valley in
increasing numbers, following both routes to enter it.
along the river linked
communities and facilitated trade; the arrival of railroads in the
late 19th century, many running along the river, supplemented
Since the late 19th century, public
sectors have heavily developed the
river. The development, commonly referred to as taming or
harnessing of the river, has been massive and multi-faceted. To aid
ship and barge navigation, locks
have been built along the lower
Columbia and its tributaries, and dredging
has opened, maintained, and enlarged shipping channels
. Since the early
20th century, dams have been built across the river for the
purposes of power generation, navigation, irrigation
, and flood control. Today, a
lies along nearly
every U.S. mile of the once free-flowing river, and much of the
Canadian stretch has been impounded as well. Production of nuclear power
has taken place at two sites
along the river. Plutonium for nuclear weapons was produced for decades at
Site, which is now the most contaminated nuclear site in
All these developments have had a tremendous impact
on river environments, perhaps most notably through industrial
pollution and barriers to fish migration.
Columbia begins its journey in the southern Rocky Mountain
Trench in British Columbia (BC). Columbia Lake, above sea level, and the
Wetlands form the river's headwaters.
The trench is a broad, deep,
and long glacial valley
and the Columbia Mountains
in BC. For its first , the
Columbia flows northwest along the trench through Windermere
Lake and the town of Invermere, a region known in BC as the Columbia Valley, then northwest to Golden and into Kinbasket Lake. Rounding the northern end of the Selkirk
Mountains, the river turns sharply south through a region
known as the Big Bend Country,
passing through Revelstoke
Lake and the Arrow Lakes. Revelstoke, the Big Bend, and the Columbia
Valley combined are referred to in BC parlance as the Columbia
Country. Below the Arrow Lakes, the Columbia passes
the cities of Castlegar, located at the Columbia's confluence with the Kootenay River, and Trail, two major centres of the West Kootenay region.
The Pend Oreille River
joins the Columbia
about north of the U.S.–Canada
Course of the Columbia River
The Columbia enters eastern
flowing south and turning to the west at the
confluence. It marks the
southern and eastern borders of the Colville Indian Reservation
the western border of the Spokane Indian Reservation
river turns south after the Okanogan
confluence, then southeasterly near the confluence with
the Wenatchee River
Washington. This C-shaped segment of the river is also known as the
"Big Bend". During the Missoula
10,000 to 15,000 years ago, much of the floodwater
took a more direct route south, forming the ancient river bed known
as the Grand Coulee
. After the floods,
the river found its present course, and the Grand Coulee was left
construction of the Grand Coulee Dam in the mid-20th century impounded the river,
forming Lake Roosevelt, from which water was pumped into the dry coulee, forming the reservoir of Banks Lake.
flows past The Gorge
Amphitheatre, a prominent concert venue in the Northwest, then
Rapids Dam, and then through the Hanford Nuclear Reservation. Entirely within the reservation is Hanford Reach, the only U.S. stretch of the river that is
completely free-flowing, unimpeded by dams and not a tidal estuary.
and Yakima River
Columbia in the Tri-Cities
population center. The Columbia makes a sharp bend to the west at
the Washington–Oregon border. The river defines that border for the
final of its journey.
Deschutes River joins the
Columbia near The
Dalles. Between The Dalles and Portland, the river cuts through the Cascade Mountains, forming the dramatic
No other river completely breaches the
Cascades—the other rivers that flow through the range also
originate in or very near the mountains. The headwaters and
upper courses of the Klamath River and
River flow through much of the Cascades; in contrast the
Columbia cuts through the range nearly a thousand miles from its
source in the Rocky Mountains.
The gorge is known for its
strong and steady winds, scenic beauty, and its role as an
important transportation link. The river continues west, bending sharply to
the north-northwest near Portland and Vancouver,
Washington, at the Willamette
Here the river slows considerably,
dropping sediment that might otherwise form a river delta
. Near Longview, Washington and the Cowlitz River
confluence, the river turns west again. The Columbia empties
into the Pacific Ocean just west of Astoria, Oregon, over the Columbia Bar, a shifting sandbar that
makes the river's mouth one of the most hazardous stretches of
water to navigate in the world.
The Columbia drains an area of about . Its drainage basin
covers nearly all of Idaho, large
portions of British Columbia, Oregon, and Washington, and small
portions of Montana, Wyoming, Utah, and
Nevada; the total
area is similar to the size of France.
Roughly of the river's length and 85 percent of its drainage
basin are in the U.S. The Columbia is the twelfth-longest river and
has the sixth-largest drainage basin in the U.S. In Canada, where
the Columbia flows for and drains , the river ranks 23rd in length,
and its basin ranks 13th in size.The Columbia shares its name with
nearby places, such as British Columbia, as well as with landforms
and bodies of water.
With an average flow at the mouth of about , the Columbia is the
largest river by volume flowing into the Pacific from North America
and is the fourth-largest by volume in the U.S. The average flow
where the river crosses the international boundary between Canada
and the U.S. is from a drainage basin of . This amounts to about
15 percent of the entire Columbia watershed. The Columbia's
highest recorded flow, measured at The Dalles, was in June 1894,
before the river was dammed. The lowest flow recorded at The Dalles was
on April 16, 1968, and was caused by the initial closure of the
The Dalles is about from the
mouth; the river at this point drains about or about 91% of the
total watershed. Flow rates on the Columbia are affected by many
large upstream reservoirs, many diversions for irrigation, and, on
the lower stretches, reverse flow from the tides
of the Pacific Ocean. The National Weather Service
tide forecasts for eight places along the river between Astoria and
the base of Bonneville Dam.
When the rifting
due to the process of plate tectonics
pushed North America away
from Europe and Africa and into the Panthalassic Ocean
(ancestor to the
modern Pacific Ocean), the Pacific Northwest was not part of the
continent. As the North American continent moved westward, the
Farallon Plate subducted
under its western margin. As the plate
subducted, it carried along island arcs
which were accreted to the North American continent, resulting in
the creation of the Pacific Northwest between 150 and
90 million years ago. The general outline of the Columbia
Basin was not complete until between 60 and 40 million years
ago, but it lay under a large inland sea later subject to uplift.
Between 40 and 20 million years ago, in the Eocene
tremendous volcanic eruptions frequently modified much of the
landscape traversed by the Columbia. The lower reaches of
the ancestral river passed through a valley near where Mount Hood later arose. Carrying sediments from erosion and
erupting volcanoes, it built a thick delta that underlies the foothills on the east
side of the Coast Range
near Vernonia in northwestern Oregon. Between
17 million and 6 million years ago, huge outpourings of
flood basalt lava covered the Columbia
River Plateau and forced the lower Columbia into its present
The Cascade Range
to uplift during the early Pleistocene
era (two million to 700,000 years ago). Cutting through the
uplifting mountains, the Columbia River created the Columbia River
The river and its drainage basin
experienced some of the world's greatest known catastrophic floods
toward the end of the last ice age
periodic rupturing of ice dams at Glacial Lake Missoula resulted in the Missoula
Floods, with discharges 10 times the combined flow of all
the rivers of the world, dozens of times over thousands of
The exact number of floods is unknown, but geologists
have documented at least 40; evidence suggests that they occurred
between about 19,000 and 13,000 years ago.
floodwaters rushed across eastern Washington, creating the channeled
scablands, which are a complex network of dry canyon-like
channels, or coulees that are often braided and sharply gouged into the basalt
rock underlying the region's deep topsoil.
Panoramic view of Columbia River
Gorge from Dog Mountain in Washington
with rich soil stand high
above the chaotic scablands. Constrictions at several places caused
the floodwaters to pool into large temporary lakes, such as
, in which sediments were
deposited. Water depths have been estimated at at
Gap, at Bonneville Dam, and over modern Portland, Oregon.
Sediments were also deposited when the floodwaters slowed in the
broad flats of the Quincy, Othello, and Pasco Basins. The floods' periodic
inundation of the lower Columbia River Plateau deposited rich sediments; 21st-century farmers in
the Willamette Valley "plow fields of fertile Montana soil and
clays from Washington's Palouse".
last several thousand years a series of large landslides have
occurred on the north side of the Columbia River Gorge, sending
massive amounts of debris south from Table Mountain and Greenleaf Peak
into the gorge near the present site of Bonneville Dam.
most recent and significant is known as the Bonneville Slide
, which formed a massive
earthen dam, filling of the river's length. Various studies have
placed the date of the Bonneville Slide anywhere between 1060 and
1760 AD; the idea that the landslide debris present today was
formed by more than one slide is relatively recent and may explain
the large range of estimates. It has been suggested that if the
later dates are accurate there may be a link with the 1700 Cascadia earthquake
. The pile
of debris resulting from the Bonneville Slide blocked the river
until rising water finally washed away the sediment. It is not
known how long it took the river to break through the barrier;
estimates range from several months to several years. Much of the
landslide's debris remained, forcing the river about south of its
previous channel and forming the Cascade Rapids.
In 1938, the construction of Bonneville Dam
inundated the rapids as well as the remaining trees that could be
used to refine the estimated date of the landslide.
the eruption of Mount St. Helens deposited large amounts of sediment in the lower
Columbia, temporarily reducing the depth of the shipping channel by
Humans have inhabited the Columbia's watershed for more than
15,000 years, with a transition to a sedentary lifestyle based
mainly on salmon starting about 3,500 years ago. In 1962,
archaeologists found evidence of human activity dating back
11,230 years at the Marmes Rockshelter, near the confluence of the Palouse and Snake
rivers in eastern Washington. In 1996, the skeletal
remains of a 9,000-year-old prehistoric man (dubbed Kennewick Man) were found near Kennewick,
The discovery rekindled debate in the
scientific community over the origins of human habitation in North
America and sparked a protracted controversy over whether the
scientific or Native American
community was entitled to possess and/or study the remains.
Many different Native Americans and First
tribes have a historical and continuing presence on the
Columbia. The Sinixt
or Lakes people lived on
the lower stretch of the Canadian portion (also claimed as part of
territory) the Secwepemc
one time the Blackfoot
on the upper; the
, Coeur d'Alene
, Nez Perce
, and the Confederated Tribes of Warm
live along the U.S. stretch. Along the upper Snake
River and Salmon River
tribes are present. The Chinook
tribe, which is not federally recognized
, also live
near the lower Columbia River. The river is known as
to the Chinook-speaking natives of its lower
reaches, and Nch’i-Wàna
to the Sahaptin
-speaking peoples of its middle
course in present-day Washington; both terms essentially mean "the
Oral histories describe the formation and destruction of the
Bridge of the
, a land bridge that connected the Oregon and Washington
sides of the river in the Columbia River Gorge. The bridge, which
aligns with geological records of the Bonneville Slide, was
described in some stories as the result of a battle between gods,
represented by Mount Adams and Mount Hood, in their competition for the affection of a
goddess, represented by Mount St. Helens.
Native American stories about the bridge
differ in their details but agree in general that the bridge
permitted increased interaction between tribes on the north and
south sides of the river.
Horses, originally acquired from Spanish New Mexico
widely via native trade networks, reaching the Shoshone of the
Snake River Plain
by 1700. The Nez
Perce, Cayuse, and Flathead
people acquired their first horses around 1730. Along with horses
came aspects of the emerging plains
, such as equestrian and horse
skills, greatly increased mobility, hunting
efficiency, trade over long distances, intensified warfare, the
linking of wealth and prestige to horses and war, and the rise of
large and powerful tribal confederacies. The Nez Perce and
Cayuse kept large herds and made annual long-distance trips to the
Plains for bison hunting, adopted the
plains culture to a significant degree, and became the main conduit
through which horses and the plains culture diffused into the
Columbia River region.
Other peoples acquired horses and
aspects of the plains culture unevenly. The Yakama, Umatilla,
Palus, Spokane, and Coeur d'Alene maintained sizable herds of
horses and adopted some of the plains cultural characteristics, but
fishing and fish-related economies remained important. Less
affected groups included the Molala
, Okanagan, and Sinkiuse-Columbia
peoples, who owned small
numbers of horses and adopted few plains culture features. Some
groups remained essentially unaffected, such as the Sanpoil
people, whose culture remained
centered on fishing.
Natives of the region encountered foreigners at several times and
places during the 18th and 19th centuries. European and
American vessels explored the coastal area around the mouth of the
river in the late 18th century, trading with local natives.
The contact would prove devastating to the Indian tribes; a large
portion of their population was wiped out by a smallpox
epidemic. Canadian explorer Alexander Mackenzie
crossed what is now
interior British Columbia in 1793. In 1805–07, the Lewis and Clark Expedition
entered the Oregon Country
Rivers, and encountered numerous small settlements of natives.
Their records recount tales of hospitable traders who were not
above stealing small items from the visitors. They also noted brass
teakettles, a British musket, and other artifacts that had been
obtained in trade with coastal tribes. From the earliest contact
with westerners, the natives of the mid- and lower Columbia were
not tribal, but instead congregated in social units no larger than
a village, and more often at a family level; these units would
shift with the season as people moved about, following the salmon
catch up and down the river's tributaries.
by the 1848 Whitman
Massacre, a number of violent battles were fought between
American settlers and the region's natives.
Indian Wars, notably the Yakima War
decimated the native population and removed much land from native
control. As years progressed, the right of natives to fish along
the Columbia became the central issue of contention with the
states, commercial fishers, and private property owners. The U.S.
Supreme Court upheld fishing rights in landmark cases in 1905 and
Dipnet fishing at Celilo Falls,
Fish were central to the culture of the region's natives, both as
sustenance and as part of their religious beliefs. Natives drew
fish from the Columbia at several major sites, which also served as
trading posts. Celilo Falls, located east of the modern city of The Dalles, was
a vital hub for trade and the interaction of different cultural
groups, being used for fishing and trading for
Prior to contact with westerners,
villages along this stretch may have at times had a population as
great as 10,000. The site drew traders from as far away as
Plains. The Cascades Rapids of the Columbia River Gorge, and Kettle Falls and Priest Rapids in eastern Washington, were also major fishing and
In prehistoric times the Columbia's salmon and steelhead runs
numbered an estimated annual average of 10 to 16 million fish.
In comparison, the largest run since 1938 was in 1986, with
3.2 million fish entering the Columbia. The annual catch by
natives has been estimated at 42 million pounds (19,000 t). The
most important and productive native fishing site was located at
Celilo Falls, which was perhaps the most productive inland fishing
site in North America. The falls were located at the border between
- and Sahaptian
-speaking peoples and served as the
center of an extensive trading network across the Pacific Plateau.
Celilo was the oldest continuously inhabited community on the North
Salmon canneries established by white settlers beginning in 1867
had a strong negative impact on the salmon population, and in 1908
U.S. President Theodore Roosevelt
observed that the salmon runs were but a fraction of what they had
been 25 years prior. Still, in the 1930s, there were natives
who lived along the river and fished year round, moving along with
the fish's migration patterns throughout the seasons.
As river development continued in the 20th century, each of
these major fishing sites was flooded by a dam, beginning with
Cascades Rapids in 1938. The development was accompanied by
extensive negotiations between natives and U.S. government
agencies. The Confederated Tribes of Warm
Springs, a coalition of various tribes, adopted a constitution
and incorporated after the 1938 completion of the Bonneville
Dam flooded Cascades Rapids; the Yakama were slower to do so, organizing a formal
government in 1944.
Today, the Yakama, Nez Perce, Umatilla,
and Warm Springs tribes all have treaty fishing rights along the
Columbia and its tributaries.
In 1957 Celilo Falls was submerged by the construction of The
Dalles Dam, and the native fishing community was displaced. The
affected tribes received a $26.8 million settlement for the
loss of Celilo and other fishing sites submerged by The Dalles Dam.
Confederated Tribes of Warm Springs used part of its
$4 million settlement to establish the Kah-Nee-Ta resort south of Mount Hood.
New waves of explorers
Some historians believe that Japanese or Chinese vessels blown off
course reached the Northwest Coast long before Europeans, possibly
as early as 219 B.C. It is unknown whether they landed near
the Columbia. Evidence exists that Spanish castaways reached the
shore in 1679 and traded with the Clatsop
if these were indeed the first Europeans to see the Columbia, they
failed to send word home to Spain.
In the 18th century, there was strong interest in discovering
a Northwest Passage
permit navigation between the Atlantic (or inland North America)
and the Pacific Ocean. Many ships in the area, especially those
under Spanish and British command, searched the northwest coast for
a large river that might connect to Hudson Bay or the Missouri River.
The first documented European discovery of
the Columbia River was that of Bruno de
, who in 1775 sighted the river's mouth. On the advice of
his officers, he did not explore it, as he was short-staffed and
the current was strong. He considered it a bay, and called it
Ensenada de Asunción
. Later Spanish maps based on his
discovery showed a river, labeled Rio de San Roque
, or an
entrance, called Entrada de Hezeta
. Following Heceta's
reports, British explorer Captain John
searched for the river in 1788 but concluded that it did
not exist. He named Cape Disappointment
non-existent river, not realizing the cape marks the northern edge
of the river's mouth.
What happened next would form the basis for decades of both
cooperation and dispute between British and American exploration
of, and ownership claim to, the region. Royal
commander George Vancouver
sailed past the mouth in April 1792 and observed a change in the
water's color, but he accepted Meares' report and continued on his
journey northward. Later that month, Vancouver encountered the
American captain Robert
Gray at the Strait of Juan de Fuca.
Gray reported that he had seen the
entrance to the Columbia and had spent nine days trying but failing
12, 1792, Gray returned south and crossed the Columbia Bar, becoming the first explorer to enter the
river. Gray's fur trading mission had been financed
by Boston merchants,
who outfitted him with a private vessel named Columbia Rediviva; he named the river
after the ship on May 18.
Gray spent nine days trading near
the mouth of the Columbia, then left without having gone beyond
upstream. The farthest point reached was Grays Bay at the mouth of
. Gray's discovery of
the Columbia was later used by the United States to support their
claim to the Oregon Country, which
was also claimed by Russia, Great
Britain, Spain and other
In October 1792, Vancouver sent Lieutenant William Robert Broughton
second-in-command, up the river. Broughton got as far as the Sandy River at the western end of the
Gorge, about upstream, sighting and naming Mount Hood. Broughton formally claimed the river, its
drainage basin, and the nearby coast
In contrast, Gray had not made any
formal claims on behalf of the United States.
the Columbia was at the same latitude as the headwaters of the
River, there was some speculation that Gray and Vancouver
had discovered the long-sought Northwest Passage.
British map showed a dotted line connecting the Columbia with the
Missouri. However, when the American explorers Meriwether Lewis
and William Clark
charted the vast,
unmapped lands of the American West
their overland expedition
(1803–05), they found no passage between the rivers. After crossing
the Rocky Mountains
, Lewis and Clark
built dugout canoes
and paddled down
the Snake River, reaching the Columbia near the present-day
Tri-Cities, Washington. They explored a few miles upriver, as far as
Island, before heading down the Columbia, concluding their
journey at the river's mouth and establishing Fort Clatsop, a short-lived establishment that was occupied for
less than three months.
Canadian explorer David
Thompson, of the North West
Company, spent the winter of 1807–08 at Kootenae
House near the source of the Columbia at present-day
Over the next few years he explored much of
the river and its northern tributaries. In 1811, he traveled down
the Columbia to the Pacific Ocean, arriving at the mouth just after
John Jacob Astor
's Pacific Fur Company
had founded Astoria.
On his return to the north, Thompson explored the one remaining
part of the river he had not yet seen, becoming the first
European-American to travel the entire length of the river.
the Hudson's Bay Company (HBC)
Vancouver on the
bank of the Columbia, in what is now Vancouver,
Washington, as the headquarters of the company's Columbia District, which encompassed
everything west of the Rocky Mountains. John McLoughlin
, a physician, was appointed
of the Columbia
District. The HBC reoriented its Columbia District operations
toward the Pacific Ocean via the Columbia, which became the
region's main trunk route. In the early 1840s Americans began to
colonize the Oregon country in large numbers via the Oregon Trail
, despite the HBC's efforts to
discourage American settlement in the region. For many the final
leg of the journey involved travel down the lower Columbia River to
Fort Vancouver. This part of the Oregon Trail, from The
Dalles to Fort Vancouver, was the trail's most treacherous stretch,
which prompted the 1846 construction of the Barlow Road.
In the Treaty of 1818
States and Britain agreed that both nations were to enjoy equal
rights in Oregon Country
10 years. By 1828, when the so-called "joint occupation" was
renewed for an indefinite period, it seemed probable that the lower
Columbia River would in time become the border. For years the
Hudson's Bay Company successfully maintained control of the
Columbia River and American attempts to gain a foothold were fended
off. In the 1830s, however, American religious missions were
established at several locations in the lower Columbia River
region. And in the 1840s a mass migration of American settlers
undermined British control. The Hudson's Bay Company tried to
maintain dominance by shifting from the fur trade, which was in
sharp decline, to exporting other goods such as salmon and lumber.
Colonization schemes were attempted, but failed to match the scale
of American settlement. Americans generally settled south of the
Columbia, mainly in the Willamette Valley. The Hudson's Bay Company
tried to establish settlements north of the river, but nearly all
the British colonists moved south to the Willamette Valley. The
hope that the British colonists might dilute the American flavor of
the valley failed in the face of the overwhelming number of
American settlers. These developments rekindled the issue of "joint
occupation" and the boundary
. While some British interests, especially the Hudson's
Bay Company, fought for a boundary along the Columbia River, the
of 1846 set the boundary
at the 49th parallel. The Columbia River did become the border
between the U.S. territories of Oregon and Washington.
Oregon became a U.S.
state in 1859, Washington in 1889.
By the turn of the 20th century, the difficulty of navigating
the Columbia was seen as an impediment to the economic development
of the Inland
region east of the Cascades. The dredging and dam
building that followed would permanently alter the river,
disrupting its natural flow but also providing electricity
and other benefits to the
captain Robert Gray and
British captain George Vancouver,
who explored the river in 1792, proved that it was possible to
cross the Columbia
A massive log raft containing an
entire year's worth of logs from one timber camp heads downriver in
Many of the challenges associated with that
feat remain today; even with modern engineering alterations to the
mouth of the river, the strong currents and shifting sandbar make
it dangerous to pass between the river and the Pacific Ocean.
The use of steamboats
along the river,
beginning with the British Beaver
in 1836 and followed by
American vessels in 1850, contributed to the rapid settlement and
economic development of the region. Steamboats operated in several distinct
stretches of the river: on its lower reaches, from the Pacific
Ocean to Cascades
Rapids; from the Cascades to Celilo Falls; from Celilo to
the confluence with the Snake River; on the Wenatchee
Reach of eastern Washington; on British Columbia's Arrow
Lakes; and on
tributaries like the Willamette, the Snake and Kootenay Lake.
The boats, initially powered by burning
wood, carried passengers and freight throughout the region for many
years. Early railroads served to connect steamboat lines
interrupted by waterfalls on the river's lower reaches. In the
1880s, railroads maintained by companies such as the Oregon Railroad and
and the Shaver Transportation Company
began to supplement steamboat operations as the major
transportation links along the river.
Opening the passage to Lewiston
As early as 1881, industrialists proposed altering the natural
channel of the Columbia to improve navigation. Changes to the river
over the years have included the construction of jetties
at the river's mouth, dredging
, and the construction of canals
and navigation locks
. Today, ocean
freighters can travel upriver as far as Portland and Vancouver, and
barges can reach as far inland as Lewiston, Idaho.
The shifting Columbia Bar makes passage between the river and the
Pacific Ocean difficult and dangerous, and numerous rapids along
the river hinder navigation. Jetties, first constructed in 1886,
extend the river's channel into the ocean. Strong currents and the
shifting sandbar remain a threat to ships entering the river and
necessitate continuous maintenance of the jetties.
In 1891 the Columbia was dredged to enhance shipping. The channel
between the ocean and Portland and Vancouver was deepened from to .
called for the
channel to be deepened to as early as 1905, but that depth was not
attained until 1976.
Navigation locks were first constructed in 1896 around the Cascades
Rapids, enabling boats to travel safely through the Columbia River
Gorge. The Celilo Canal
Celilo Falls, opened to river traffic in 1915. In the
mid-20th century, the construction of dams along the length of
the river submerged the rapids beneath a series of reservoirs. An
extensive system of locks allowed ships and barges to pass easily
from one reservoir to the next. A navigation channel reaching to
, along the Columbia and Snake Rivers, was
completed in 1975. One of the main commodities is wheat, mainly for
export. More than 40 percent of all US wheat exports are
barged on the Columbia River.
eruption of Mount St. Helens caused mudslides in the area, which reduced the
Columbia's depth by for a stretch, disrupting Portland's
Deeper shipping channel
, one of three
Army Corps of Engineers dredges tasked with ongoing maintenance of
the Columbia's shipping channel, began service in 1983.
Efforts to maintain and improve the navigation channel have
continued to the present day. In 1990, a new round of studies
examined the possibility of further dredging on the lower Columbia.
The plans were controversial from the start because of economic and
In 1999, Congress authorized deepening the channel between Portland
and Astoria from , which will make it possible for large container
and grain ships to reach Portland and Vancouver. However, the
project has met opposition because of concerns about stirring up
toxic sediment on the riverbed. Portland-based Northwest
Environmental Advocates brought a lawsuit against the Army Corps of
Engineers, but it was rejected by the Ninth
Court of Appeals
in August 2006. The project includes measures
to mitigate environmental damage; for instance, for every acre
(0.40 ha) of wetland damaged by the project, the U.S. Army Corps of
must restore of wetland. In early 2006, the Corps
spilled of hydraulic oil into the Columbia, drawing further
criticism from environmental organizations.
Work on the project began in 2005 and is expected to conclude in
2010. The project's cost is estimated at $150 million. The
federal government is paying 65 percent, Oregon and Washington
are paying $27 million each, and six local ports are also
contributing to the cost.
Dams: harnessing the river
Kinbasket Lake, a reservoir on the
In 1902, the United
States Bureau of Reclamation
was established to aid in the
. One of its major
undertakings was building Grand Coulee Dam to provide irrigation for the of the Columbia Basin Project in central
With the onset of World
, the focus of dam construction shifted to production of
efforts resumed after the war.
River development occurred within the structure of the 1909
Boundary Waters Treaty
between the U.S. and Canada. The
United States Congress
the Rivers and Harbors Act
, which directed the Army Corps of Engineers and the
Federal Power Commission
explore the development of the nation's rivers. This prompted
agencies to conduct the first formal financial analysis of
hydroelectric development; the reports produced by various agencies
were presented in House Document 308. Those reports, and
subsequent related reports, are referred to as 308 Reports
late 1920s, political forces in the Northwestern
United States generally favored private development of
hydroelectric dams along the Columbia.
But the overwhelming
victories of gubernatorial candidate George W. Joseph
in the 1930 Oregon Republican Party
later his law partner Julius Meier
were understood to demonstrate strong public support for public
ownership of dams. In 1933, President Franklin D. Roosevelt
signed a bill that enabled
the construction of the Bonneville and Grand Coulee dams as public
works projects. The legislation was attributed to the efforts of
Oregon Senator Charles McNary
Washington Senator Clarence Dill
Oregon Congressman Charles Martin
floods swept through the Columbia watershed, destroying Vanport, then the second largest city in Oregon, and
impacting cities as far north as Trail, British Columbia.
The flooding prompted the United States Congress
to pass the
Flood Control Act of 1950
authorizing the federal development of additional dams and other
flood control mechanisms. By that time, however, local communities had
become wary of federal hydroelectric projects, and sought local
control of new developments; a Public Utility District in Grant
County, Washington ultimately began construction of the dam at Priest
In the 1960s, the United States and Canada signed the Columbia River Treaty
, which focused
on flood control and the maximization of downstream power
generation. Canada agreed to build dams and provide reservoir
storage, and the U.S. agreed to deliver to Canada one-half of the
increase in U.S. downstream power benefits as estimated five years
in advance. Canada's obligation was met by building three dams (two
on the Columbia, and one on the Duncan
), the last of which was completed in 1973.
Today the main stem of the Columbia River has 14 dams, of
which three are in Canada and 11 in the U.S. Four mainstem dams
and four lower Snake River
dams contain navigation
locks to allow ship and barge passage from the ocean as far as
The river system as a whole has more than
400 dams for hydroelectricity and irrigation. The dams address
a variety of demands, including flood
, navigation, stream flow regulation, storage and
delivery of stored waters, reclamation
of public lands and Indian reservations, and the generation of
The larger U.S. dams are owned and operated by the federal
government (some by the Army Corps of
and some by the Bureau of Reclamation), while the
smaller dams are operated by public utility districts
private power companies. The federally operated system is known as
the Federal Columbia
River Power System
, which includes 31 dams on the Columbia
and its tributaries. The system has altered the seasonal flow of
the river in order to meet higher electricity demands during the
winter. At the beginning of the 20th century, roughly
75 percent of the Columbia's flow occurred in the summer,
between April and September. By 1980, the summer proportion had
been lowered to about 50 percent, essentially eliminating the
The installation of dams dramatically altered the landscape and
ecosystem of the river. At one time, the Columbia was one of the
-producing river systems in the
world. Previously active fishing sites, most
Falls in the eastern Columbia River Gorge, have exhibited
a sharp decline in fishing along the Columbia in the last century,
and salmon populations have been dramatically reduced.
have been installed at some
dam sites to help the fish journey to spawning waters. Chief Joseph
Dam has no fish ladders and completely blocks fish
migration to the upper half of the Columbia River
[[Image:Columbia dams map.png|thumb|right|350px|alt=A map shows the
locations of many river dams on the Columbia River and its
tributaries. They extend from near the river mouth in Oregon and
Washington all the way up these rivers into Nevada, Idaho, Wyoming,
Montana, and British Columbia. | Prominent dams of the Columbia
River Basin. Color indicates dam ownership:
The Bureau of Reclamation
Columbia Basin Project
focused on the generally dry region of central Washington known as
the Columbia Basin, which features rich loess
soil. Several groups developed competing proposals, and in 1933,
President Franklin D. Roosevelt
authorized the Columbia
Basin Project. The Grand Coulee Dam was the project's central component; upon
completion, it pumped water up from the Columbia to fill the
formerly dry Grand Coulee, forming
By 1935, the intended height of the dam was
increased from a range between to , a height that would extend the
lake impounded by the dam all the way to the Canadian border; the
project had grown from a local New Deal
relief measure to a major national project.
project's initial purpose was irrigation,
but the onset of World War II created a
high demand for electricity, mainly for aluminum production and for the development of
nuclear weapons at the Hanford Site.
Irrigation began in 1951. The project
provides water to more than of fertile but arid land in central
Washington, transforming the region into a major agricultural
center. Important crops include orchard
, and wine grapes
Since 1750, the Columbia has experienced six multi-year droughts.
The longest, lasting 12 years in the mid-1800s, reduced the
river's flow to 20 percent below average. Scientists have
expressed concern that a similar drought would have grave
consequences in a region so dependent on the Columbia. In
1992–1993, a lesser drought affected farmers, hydroelectric power
producers, shippers, and wildlife managers.
Many farmers in central Washington build dams on their property for
irrigation and to control frost on their crops. The Washington
Department of Ecology, using new techniques involving aerial
photographs, estimated there may be as many as a hundred such dams
in the area, most of which are illegal. Six such dams have failed
in recent years, causing hundreds of thousands of dollars of damage
to crops and public roads. Fourteen farms in the area have gone
through the permitting process to build such dams legally.
[[Image:Woody Guthrie NYWTS.jpg|thumb|upright|left|alt=Half-length
photo of a middle-aged man sitting in front of a closed door and
playing a guitar and singing. His wavy black hair is partly covered
by a black hat tipped at a rakish angle. He wears a striped flannel
work shirt. His black guitar has a sign on it that says, "This
machine kills fascists".|Roll on, Columbia, roll on, roll on,
Columbia, roll on / Your power is turning our darkness to dawn /
Roll on, Columbia, roll on.
Lyrics from Woody Guthrie
's Roll on Columbia
, written for the Bonneville Power
The Columbia's heavy flow and extreme elevation drop over a short
distance, , give it tremendous capacity for hydroelectricity
generation. In comparison,
the Mississippi drops less than . The Columbia alone possesses
one-third of the United States's hydroelectric potential.
largest of the 150 hydroelectric projects, the Grand Coulee
Dam and the Chief Joseph Dam, are also the largest in the United States and
among the largest in the
Inexpensive hydropower supported the emergence of an extensive
industry, which draws tremendous
amounts of power. Until 2000, the Northwestern
United States produced up to 17 percent of the world's
aluminum and 40 percent of the aluminum produced in the
But the commoditization of power in the early 2000s,
coupled with drought that reduced the generation capacity of the
river, damaged the industry. By 2001, Columbia River aluminum
producers had idled 80 percent of its production capacity, and
by 2003, the entire U.S. produced only 15 percent of the
world's aluminum, many smelters among the Columbia having gone
dormant or out of business.
Power remains relatively inexpensive along the Columbia, and in
recent years high-tech companies like Google
have begun to move server farm
operations into the area to avail themselves of cheap power.
Downriver of Grand Coulee, each dam's reservoir is closely
regulated by the Bonneville Power
(BPA), Army Corps of Engineers, and various
Washington Public Utility Districts to ensure flow, flood control,
and power generation objectives are met. Increasingly, hydro-power
operations are required to meet standards under the U.S. Endangered Species Act
agreements to manage operations to minimize impacts on salmon and
other fish, and some conservation and fishing groups support
removing four dams on the lower Snake
, the largest tributary of the Columbia.
the BPA hired Oklahoma folksinger Woody
Guthrie to write songs for a documentary film promoting the
benefits of hydropower.
In the month he spent traveling the
region Guthrie wrote 26 songs
, which have
become an important part of the cultural history of the
Ecology and environment
The Columbia supports several species of anadromous
fish that migrate between the Pacific
Ocean and fresh water tributaries of the river. Coho
(also known as "king") salmon, and steelhead
, all of the genus Oncorhynchus
, are ocean fish that migrate up
the rivers at the end of their life cycles to spawn. White sturgeon
, which take 15 to
25 years to mature, typically migrate between the ocean and
the upstream habitat several times during their lives.
Salmon populations declined dramatically after the establishment of
canneries in 1867. By 1908, there was widespread concern about the
decline of salmon and sturgeon. In that year, the people of Oregon
passed two laws under their newly instituted program of Citizens' Initiatives
limiting fishing on the
Columbia and other rivers. Then in 1948, another initiative banned
the use of seine nets
invented by Native Americans, and refined by later settlers)
Dams interrupt the migration of anadromous fish. Salmon and
steelhead return to the streams in which they were born to spawn;
where dams prevent their return, entire populations of salmon die.
Some of the Columbia and Snake River dams employ fish ladders
, which are effective to varying
degrees at allowing these fish to travel upstream. Another problem
exists for the juvenile salmon headed downstream to the ocean.
Previously, this journey would have taken two to three weeks. With
river currents slowed by the dams, and the Columbia converted from
wild river to a series of slackwater pools, the journey can take
several months, which increases the mortality rate. In some cases,
the Army Corps of Engineers transports juvenile fish downstream by
truck or river barge. The Chief Joseph Dam and several dams on the Columbia's tributaries
entirely block migration, and there are no migrating fish on the
river above these dams.
Sturgeon have different migration
habits and can survive without ever visiting the ocean. In many
upstream areas cut off from the ocean by dams, sturgeon simply live
upstream of the dam.
Not all fish have suffered from the modifications to the river; the
known as the squawfish
) thrives in the warmer, slower
water created by the dams. Research in the mid-1980s found that
juvenile salmon were suffering substantially from the predatory
pikeminnow, and in 1990, in the interest of protecting salmon, a
"bounty" program was established to reward anglers for catching
In 1994, the salmon catch was smaller than usual in the rivers of
Oregon, Washington, and British Columbia, causing concern among
commercial fishermen, government agencies, and tribal leaders. U.S.
government intervention, to which the states of Alaska, Idaho, and
Oregon objected, included an 11-day closure of an Alaska fishery.
1994 the Pacific
Fisheries Management Council unanimously approved the strictest
regulations in 18 years, banning all commercial salmon fishing
for that year from Cape
Falcon north to the Canadian border.
In the winter
of 1994, the return of coho salmon
exceeded expectations, which was attributed in part to the fishing
Also in 1994, United States Secretary
of the Interior Bruce Babbitt
first proposed the removal of several Pacific Northwest dams
because of their impact on salmon spawning. The Northwest Power Planning
approved a plan that provided more water for fish and
less for electricity, irrigation, and transportation. Environmental
advocates have called for the removal of certain dams in the
Columbia system in the years since. Of the 227 major dams in
the Columbia River drainage basin, the four Washington dams on the
lower Snake River
are often identified
for removal, notably in an ongoing lawsuit concerning a Bush administration
salmon recovery. These dams and reservoirs currently limit
the recovery of upriver salmon runs to Idaho's Salmon and Clearwater rivers.
Historically, the Snake produced over 1.5 million spring and
summer Chinook Salmon
, a number that
has dwindled to several thousand in recent years. Idaho Power Company's Hells Canyon dams have no fish ladders (and do not pass juvenile
salmon downstream), and thus allow no steelhead or salmon to
migrate above Hells Canyon. In 2007, the destruction of the Marmot
Dam on the Sandy
River was the first dam removal in the system.
plans to remove the Condit
Dam on Washington's White Salmon River, and the Milltown Dam
on the Clark Fork in Montana.
southeastern Washington, a stretch of the river passes through the
Site, established in 1943 as part of the Manhattan Project.
The site served
as a plutonium
production complex, with
nine nuclear reactors
facilities located on the banks of the river. From 1944 to 1971,
pump systems drew cooling water from the river and, after treating
this water for use by the reactors, returned it to the river.
Before being released back into the river, the used water was held
in large tanks known as retention basins for up to six hours.
were not affected by
this retention, and several terabecquerels
entered the river every day. By 1957, the eight plutonium
production reactors at Hanford dumped a daily average of
of radioactive material
into the Columbia. These releases were kept secret by the federal
government until the release of declassified documents in the late
1980s. Radiation was measured downstream as far
west as the Washington and Oregon
The nuclear reactors were decommissioned at the end of the Cold War
, and the Hanford site is now the focus of
the world's largest environmental cleanup
, managed by
the Department of
under the oversight of the Washington Department of
and the Environmental
. Nearby aquifers contain an estimated
270 billion US gallons
(1 billion m3
) of groundwater contaminated by
high-level nuclear waste
that has leaked out of Hanford's
massive underground storage tanks. As of 2008,
1 million US gallons (3,785 m3
highly radioactive waste is traveling through groundwater toward
the Columbia River. This waste is expected to reach the river in 12
to 50 years if cleanup does not proceed on schedule.
In addition to concerns about nuclear waste, numerous other
pollutants are found in the river. These include chemical
pesticides, bacteria, arsenic, dioxins, and polychlorinated biphenyl
Studies have also found significant levels of toxins in fish and
the waters they inhabit within the basin. Accumulation of toxins in
fish threatens the survival of fish species, and human consumption
of these fish can lead to health problems. Water quality is also an
important factor in the survival of other wildlife and plants that
grow in the Columbia River drainage basin. The states, Indian
tribes, and federal government are all engaged in efforts to
restore and improve the water, land, and air quality of the
Columbia River drainage basin and have committed to work together
to enhance and accomplish critical ecosystem restoration efforts.
of cleanup efforts are currently underway, including Superfund projects at Portland Harbor, Hanford,
Timber industry activity further contaminates river water, notably
in the increased sediment runoff that results from clearcuts
. The Northwest Forest Plan
, a piece of
federal legislation from 1994, mandated that timber companies
consider the environmental impacts of their practices on rivers
like the Columbia.
On July 1, 2003, Christopher Swain of Portland, Oregon, became the
first person to swim the Columbia River's entire length, in an
effort to raise public awareness about the river's environmental
Most of the Columbia's drainage basin
(which, at , is about the size of France) lies roughly between the
Rocky Mountains on the east and the Cascade Mountains on the west.
In the United States and Canada the term watershed is often used to
mean drainage basin. The term Columbia Basin
is used to
refer not only to the entire drainage basin but also to subsets of
the river's full watershed, such as the relatively flat and
unforested area in eastern Washington bounded by the Cascades, the
Rocky Mountains, and the Blue Mountains. Within the watershed are
diverse landforms including mountains, arid plateaus, river
valleys, rolling uplands, and deep gorges. Grand Teton
National Park lies in the watershed, as well as parts of Yellowstone
National Park, Glacier National Park, Mount Rainier National Park, and North Cascades National Park. Canadian National Parks in the watershed
National Park, Yoho National Park, Glacier National Park, and Mount Revelstoke National
Park. Hells Canyon, the deepest gorge in North America, and the
Gorge are in the watershed.
widely, ranging from Western
and Western redcedar
the moist regions to sagebrush
in the arid
regions. The watershed provides habitat for 609 known fish and
wildlife species, including the bull
, Bald Eagle
, gray wolf
, and Canada lynx
The World Wide Fund for
(WWF) divides the waters of the Columbia and its
tributaries into three freshwater
, naming them: Columbia Glaciated, Columbia
Unglaciated, and Upper Snake. The Columbia Glaciated ecoregion,
making up about a third of the total watershed, lies in the north
and was covered with ice sheets during the Pleistocene
. The ecoregion includes the mainstem
Columbia north of the Snake River and tributaries such as the
Yakima, Okanagan, Pend Oreille, Clark Fork, and Kootenay Rivers.
The effects of glaciation
include a number
of large lakes and a relatively low diversity of freshwater fish.
Snake ecoregion is defined as the Snake River watershed above
Falls, which totally blocks fish migration.
region has 14 species of fish, many of which are endemic
. The Columbia Unglaciated ecoregion makes
up the rest of the watershed. It includes the mainstem Columbia
below the Snake River and tributaries such as the Salmon, John Day,
Deschutes, and lower Snake Rivers. Of the three ecoregions it is
the richest in terms of freshwater species diversity. There are
35 species of fish, of which four are endemic. There are also
high levels of mollusk endemism.
In 2000, about six million people lived within the Columbia's
drainage basin. Of this total about 2.4 million people lived
in Oregon, 1.7 million in Washington, 1 million in Idaho,
half a million in British Columbia, and 0.4 million in
Montana. Population in the watershed has been rising for many
decades and is projected to rise to about 10 million by 2030.
The highest population densities are found west of the Cascade
Mountains along the I-5
especially in the Portland-Vancouver urban area. High densities are
also found around Spokane, Washington, and Boise,
Although much of the watershed is rural and
sparsely populated, areas with recreational and scenic values are
growing rapidly. The central Oregon county of Deschutes is the fastest-growing in the state.
Populations have also been growing just east
of the Cascades in central Washington around the city of Yakima and the Tri-Cities area.
for the coming decades assume growth throughout the watershed,
including the interior. The Canadian part of the Okanagan
subbasin is also growing rapidly.
Climate varies greatly from place to place within the watershed.
Elevation ranges from sea level
river mouth to more than in the mountains, and temperatures vary
with elevation. The highest peak is Mount Rainier, at .
High elevations have cold winters
and short cool summers; interior regions are subject to great
temperature variability and severe droughts. Over some of the
watershed, especially west of the Cascade Mountains, precipitation
maximums occur in winter, when Pacific storms come ashore.
Atmospheric conditions block the flow of moisture in summer, which
is generally dry except for occasional thunderstorms in the
interior. In some of the eastern parts of the watershed, especially
regions with Continental climate
precipitation maximums occur in early summer. Annual precipitation
varies from more than a year in the Cascades to less than in the
interior. Much of the watershed gets less than a year.
Several major North American drainage basins and many minor ones
share a common border with the Columbia River's drainage basin.
east, in northern Wyoming and Montana, the Continental Divide separates the Columbia
watershed from the Mississippi-Missouri watershed, which empties into the Gulf of
Mexico. To the northeast, mostly along the southern
border between British Columbia and Alberta, the Continental Divide separates the Columbia
watershed from the Nelson-Lake
Winnipeg-Saskatchewan watershed, which empties
Bay. The Mississippi and Nelson watersheds are
separated by the Laurentian
Divide, which meets the Continental Divide at Triple
Divide Peak near the headwaters of the Columbia's Flathead River tributary.
marks the meeting of three of North America's main drainage
patterns, to the Pacific Ocean, to Hudson Bay, and to the Atlantic
Ocean via the Gulf of Mexico.
north along the Continental Divide, a short portion of the combined
Continental and Laurentian divides separate the Columbia watershed
from the MacKenzie-Slave-Athabasca watershed, which empties into the
The Nelson and Mackenzie watersheds are
separated by a divide between streams flowing to the Arctic Ocean
and those of the Hudson Bay
. This divide meets the Continental Divide at
Dome (also known as Dome), near the northernmost bend of
the Columbia River.
southeast, in western Wyoming, another divide separates the
Columbia watershed from the Colorado-Green watershed,
which empties into the Gulf of California.
The Columbia, Colorado, and Mississippi
watersheds meet at Three Waters Mountain in the Wind River Range
of To the south, in
Oregon, Nevada, Utah, Idaho, and Wyoming, the Columbia watershed is
divided from the Great Basin
several watersheds are endorheic
not emptying into any ocean but rather drying up or sinking into
. Great Basin watersheds that share a border
with the Columbia watershed include Harney Basin, Humboldt River, and
To the north, mostly in British Columbia,
the Columbia watershed borders the Fraser
watershed. To the west and southwest the Columbia
watershed borders a number of smaller watersheds that drain to the
Pacific Ocean, such as the Klamath
River in Oregon and California and the Puget Sound Basin in Washington.
The Columbia receives more than 60 significant tributaries
. The four largest that empty directly into
the Columbia (measured either by discharge or by size of watershed) are
the Snake River (mostly in Idaho), the
Willamette River (in northwest
Oregon), the Kootenay River (mostly
in British Columbia), and the Pend
Oreille River (mostly in northern Washington and Idaho, also
known as the lower part of the Clark
Each of these four averages more than and drains
an area of more than .
The Snake is by far the largest tributary. Its watershed of is
larger than the state of Idaho. Its discharge is nearly equal
(about 46.5%) to the Columbia's at the rivers' confluence. Compared
to the Columbia above the confluence, the Snake is longer (113%),
and its drainage basin is larger (104%).
The Pend Oreille river system (including its main tributaries, the
Clark Fork and Flathead rivers) is also similar in size to the
Columbia at their confluence. Compared to the Columbia River above
the two rivers' confluence, the Pend Oreille-Clark-Flathead is
nearly as long (about 86%), its basin about three-fourths as large
(76%), and its discharge over a third (37%).
|Kootenay River (Kootenai)
|Pend Oreille River
|John Day River
Notes and references
- According to the United States Geological Survey fact sheet,
"Largest Rivers in the United States", "Rivers
are considered large on the basis of one or more of three
characteristics: total length from source to mouth, area of basin
(watershed) drained by the stream, and average rate of flow
(discharge) at the mouth." The Columbia is the largest river of the
Pacific Northwest in all three senses.
- This number was derived from the rivers list published in Atlas Canada
by Natural Resources Canada.
- Bishop, p. 98
- Bishop, pp. 226–29
- online at Google Books
- Bishop, p. 227
- URL is to the Google Book Search version.
- Archie Satterfield, Country Roads of Washington
(Backinprint.com: 2003) ISBN 0-595-26863-3, page 82
- People of the Dalles, pp. 12–13.
- Empty Nets, p. 14.
- Empty Nets, p. 6.
- Attributed to anthropologist Philip Drucker in Cultures of
the North Pacific Coast in:
- URL is to the Google Book Search version.
- Empty Nets, p. 5.
- Empty Nets, p. 11.
- "It is a near certainty that Japanese or Chinese people arrived
on the northwest coast long before any European."
- Denton, V.L. The Far West Coast, p. 174. Toronto,
- URL is to the Google Book Search version.
- online at Google Books
- online at Google Books
- URL is to a reprint of a 1902 magazine edition of the
Pendleton Daily Tribune published by E.P. Dodd.
- online at Google Books
- The Oregonian, January 1, 1895, p. 8
- Harris, Stephen L. (1988). Fire Mountains of the West: The
Cascade and Mono Lake Volcanoes. Missoula: Mountain Press
Publishing Company, Missoula. page 209. ISBN 0-87842-220-X
- URL is to the Google Book Search version.
- Smith, Courtland L.: Seine fishing in the Oregon
- ; ;
- The associated triple divide points are Commissary Ridge North, Wyoming, and Sproats Meadow Northwest, Oregon.
- Calculated mainly with data from:
- Sum of Subregion 1704, Upper Snake, Subregion 1705, Middle
Snake, and Subregion 1706, Lower Snake.
- Willamette River Basin, Portland Bureau of
Environmental Services (2008). Retrieved on 2008-09-16.
- Subbasin Overview, Kootenai Subbasin Plan, Northwest Power and
- The Rivers, Balance of Power: Hydroelectric
Development in Southeastern British Columbia; Touchstones Nelson:
Museum of Art and History. Retrieved on 2008-09-16.
- Discharge data taken from a gauge at the U.S.–Canada border,
from the mouth, measuring data from about , about 98 percent
of the total watershed.
- Discharge data taken from gauge 14243000 at Castle
Rock, from the mouth, measuring the flow from about or
85 percent of the total watershed.
- Calculated by summing subbasin sizes listed in Lower Columbia Tributaries, Northwest Power and
Conservation Council; and Toutle Management Plan, Northwest Power and
Conservation Council. Retrieved on 2008-09-16.
- Discharge data from gauge 12510500 at Kiona, from the mouth,
measuring the flow from about 91 percent of the total
- . Discharge data from gauge 12459000 at Peshastin, from the
mouth, measuring the the flow from about or 77 percent of the
- Water Data Report WA-05-1, chapter Okanagan River Basin. Retrieved on 2007-04-20.
Discharge data taken at Malott, Washington, from the mouth,
measuring the flow from about , about 97 percent of the total
- Discharge data from a gauge near Laurier, from the mouth,
measuring the flow from about , about 90 percent of the total
- Upper Columbia Subbasin Overview, Section 29,
p. 8; Northwest Power and Conservation Council. Retrieved on
- Discharge data from a gauge near Bull Run, from the mouth,
measuring the flow from about , about 86 percent of the total
- Discharge data from a gauge at McDonald Ferry, from the mouth,
measuring the flow from about , about 95 percent of the total