Where is the Columbia River Located

Numerous Native American peoples inhabited the Columbia River basin for several thousand years. Spanish explorers sailing up the Pacific coast in about 1775 probably were the first Europeans to sight the river’s mouth including early explorations in 1792 by Captain Robert Gray, a Boston trader who named the 7th largest river in North America after his boat. Where is the Columbia River located?

The Columbia River is located in the Pacific Northwest region of North America rising in the Rocky Mountains of British Columbia, Canada-flows into Washington State & Oregon before emptying into the Pacific Ocean at Astoria, Oregon. Its drainage basin extends into 7 US states & 1 Canadian province.

Since the early 20th century, dams have been built across the river for generating power, navigation, irrigation, and flood control. The 14 hydroelectric dams on Columbia’s main stem and many more on its tributaries produce more than 44 percent of total U.S. hydroelectric generation.


Where Does the Columbia River Start and Stop


Columbia Lake, headwaters of the Columbia River | Mapio.net The Columbia River is the largest river that flows in the Pacific Ocean from North America and South America. The headwaters begin between Columbia Lake in the Rocky Mountain Trench and the Selkirk Mountains, of southeastern British Columbia at about 2,656 feet above sea level.

The river flows north for some 200 miles (322 kilometers) and then turns south and flows for about 270 miles (434 kilometers) before moving through the border of northeastern Washington at River Mile 749, which is 749 miles inland from the Pacific Ocean. This area of the river is called the Big Bend.

Because of its unique situation close to the ocean and laced with tall mountain ranges, Columbia evolved as one of the great rivers of the world in terms of its runoff and the diversity of its habitat. From its headwaters to its mouth, the river drops steadily at a rate of about two feet per mile emptying into the Pacific Ocean at Astoria, Oregon.

The Columbia River Basin covers 258,000 square miles west of the Continental Divide which includes parts of seven U.S. states and one Canadian province. It’s a more than  1,200-mile course that ends in the Pacific ocean.

The Columbia River flows through four mountain ranges and drains more water to the Pacific Ocean than any other river in North or South America. The Columbia once produced the largest salmon runs on earth, with returns often exceeding 30 million salmon per year. Today, unfortunately only a fraction return to spawning in the river.

Columbia River Length



The Columbia River runs through the Pacific Northwest region, beginning in Canada and running 1,253 miles to the Pacific Ocean. Up to 500 miles of the river lie in Canada. It has its source in Canada and flows to the Pacific Ocean in the state of Oregon in the United States.

The starting point is at Columbia Lake, located 2,690 feet above sea level in British Columbia, where the river is sourced at its headwaters. It takes 146 miles to get from Bonneville Dam to the Pacific Ocean on the lower Columbia River. The Columbia ranks 7th among 135 U.S. rivers that are more than 100 miles long.


Columbia River Map


From 1  1/2 miles below the Cascade Range, the river widens to a maximum of 6 miles near its mouth, and it discharges into the ocean between jetties 2 miles apart. The navigable channel depth is kept at 40 feet as far as Portland and at 27 feet between Portland and Bonneville Locks. Depths to 300 feet have been measured near The Dalles, Oregon and to 200 feet in the lower river and estuary.

Near Birchbank, British Columbia, the river’s rate of flow is 32 million gallons per minute GPM at The Dalles Dam, which is 88 million GPM; and at the mouth, the rate of flow is 123 million GPM. Ocean tides affect the flow as far upstream as Bonneville Dam is 145 miles above the mouth.

The Snake River tributary to the south travels over 1000 miles from Yellowstone National Park to merge with the Columbia River near Pasco in Washington State. Each year over 17 1/2 trillion gallons of water runoff are discharged into the Pacific at Astoria, Oregon. This is the largest runoff from any river discharging in the Pacific from North and South America.



Columbia River - American Rivers


The Kootenai, Pend Oreille, Spokane, Okanogan, Wenatchee, Yakima, Snake, Lewis, Cowlitz, John Day, Deschutes, and Willamette Rivers are major tributaries of the Columbia River. These tributaries of the Columbia River have drained the Northwest region for millions of years.



Columbia River Basin


The river also provides drinking water to numerous communities along its course and irrigates 600,000 acres of farmland. Between the U.S. and Canada, the river’s 19 hydroelectric dams provide about half the region’s supply of electric power, in addition to providing flood control benefits. Sadly, the dams have also played a major role in the decline of numerous salmon and steelhead populations, including 13 stocks of Salmon currently listed under the Endangered Species Act. Populations of Pacific lamprey and sturgeon have also been impacted, and the water quality of the river has declined as a result of the dams.

The largest tributary of the Columbia is the Snake River. Its drainage basin is roughly the size of France and extends into seven US states and a Canadian province. The fourth-largest river in the United States by volume.  The Columbia River and its tributaries have been central to the region’s culture and economy for thousands of years.

They have been used for transportation, fishing, and other industries since ancient times, linking the region’s many cultural groups. The river system hosts many species of anadromous fish, which migrate between freshwater habitats and the salt waters of the Pacific Ocean. These fish especially the salmon species provided the core subsistence for native American peoples.

Columbia River Facts



The numerous Dams and reservoirs that have been built on the Columbia over the years have changed the Columbia River’s natural flows. Spring run-off is captured behind dams, thereby reducing flows and hampering the migration of young salmon headed out to sea, exposing them to predators in a series of slow-moving reservoirs. Reduced flows also harm the health of the Columbia River estuary by shrinking the size of the river’s freshwater flow.

Columbia River Treaty, (Jan. 17, 1961), was an agreement between Canada and the United States to develop and share waterpower and storage facilities on the Columbia River. The treaty called for the United States to build Libby Dam in northern Montana and for Canada to build dams at three locations in British Columbia.

The Portland District operates three locks and four dams in the Columbia River basin. Each dam contributes to a water resource management system that provides flood risk management, power generation, water quality improvement, irrigation, fish and wildlife habitat, and recreation on the Columbia River and some of its tributaries.

An average of 10 to 20 inches of rain falls annually in most of the Columbia River basin, and between 40 to 140 inches fall annually at the lower elevations of the basin between the mouth and the Columbia River Gorge.

Because of the River’s large flow and quick drop in elevation, this made for perfect conditions for creating Hydroelectricity. Through the years 14 hydroelectric dams were built on Columbia’s main stem and many more on its tributaries producing more than 44 percent of total U.S. hydroelectric generation.


Columbia River Highway


Part of the beauty of this area is detailed with a 70-mile trip down the Columbia River Highway. In order to travel the Byway itself, follow the keystone signs from Troutdale east to Dodson and from Mosier east to The Dalles.

To get to the Byway from Portland, follow Interstate 84 east to the Sandy River in Troutdale. Take exit 18 and travel south along the Sandy River to the Sandy River Bridge. Follow the keystone-shaped signs through Springdale, Corbett, and the waterfall area to the junction with Interstate 84. Continue east on Interstate 84 to Mosier (exit 69). Follow the keystone signs through Mosier to Rowena Crest, and then to Chenoweth Creek, located just west of The Dalles.
– Please note that the eastern part of the Byway is US 30, but the western part is not. According to Oregon.com article- Historic Columbia River Highway

This is the first scenic highway in the US to gain the distinction of National Historic Landmark. Just to give you an idea of what this means, less than 3 percent of the sites on the National Register of Historic Places become Landmarks. The construction of this Highway was considered one of the greatest engineering feats of the modern age. Its engineer, Samuel C. Lancaster, did not [want] to mar what God had put there. It was designed in 1913 to take advantage of the many waterfalls and other “beauty spots.”





Where Does the Hudson River Start and End

Read about the famous American river right here at MyWaterEarth&Sky-The Hudson River although fairly small compared to other rivers in the United States is very important and has a rich history. Its banks have been inhabited by Native Americans ….… Continue reading


JimGalloway Author/Editor



References: American Rivers- The Columbia River

US Army Corps of Engineers-The Columbia 




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