Willamette River facts for kids

Quick facts for kids Willamette River
8 bridges across the Williamette River in Downtown Portland. From front to back: Fremont Bridge, Broadway Bridge, Steel Bridge, Burnside Bridge, Morrison Bridge, Hawthorne Bridge, Marquam Bridge, Ross Island Bridge
Name origin: From a Clackamas Native American village name
Country	United States
State	Oregon
Cities	Eugene, OR, Corvallis, OR, Albany, OR, Salem, OR, Newberg, OR, Wilsonville, OR, Portland, OR
Source	Confluence of Middle Fork Willamette River and Coast Fork Willamette River
- location	near Eugene, Lane County, Oregon
- elevation	438 ft (134 m)
Mouth	Columbia River
- location	Portland, Multnomah County, Oregon
- elevation	10 ft (3 m)
Length	187 mi (301 km)
Basin	11,478 sq mi (29,730 km²)
Discharge	for Morrison Bridge, Portland, 12.8 miles (20.6 km) from mouth
- average	33,010 cu ft/s (900 m³/s)
- max	420,000 cu ft/s (11,900 m³/s)
- min	4,200 cu ft/s (100 m³/s)

The Willamette River is a major tributary of the Columbia River, accounting for 12 to 15 percent of the Columbia's flow. The Willamette's main stem is 187 miles (301 km) long, lying entirely in northwestern Oregon in the United States. Flowing northward between the Oregon Coast Range and the Cascade Range, the river and its tributaries form the Willamette Valley, a basin that contains two-thirds of Oregon's population, including the state capital, Salem, and the state's largest city, Portland, which surrounds the Willamette's mouth at the Columbia.

Originally created by plate tectonics about 35 million years ago and subsequently altered by volcanism and erosion, the river's drainage basin was significantly modified by the Missoula Floods at the end of the most recent ice age. Humans began living in the watershed over 10,000 years ago. There were once many tribal villages along the lower river and in the area around its mouth on the Columbia. Indigenous peoples lived throughout the upper reaches of the basin as well.

Images for kids

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  Ocean-going cargo ship anchored at the mouth of the Willamette

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  The Multnomah Channel from the Sauvie Island Bridge

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  The Oregon Route 34 bridge across the Willamette River at Corvallis is a mid-valley highway crossing.

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  The glacial Bellevue Erratic at Erratic Rock State Natural Site. The rock was transported to the Willamette Valley by the Missoula Floods.

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  Willamette Valley map showing main stem and major tributaries

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  The Willamette River near the confluence with the Molalla River

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  A boulder at Alton Baker Park in Eugene engraved with the Kalapuyan "Whilamut" "Where the river ripples and runs fast"

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  Oregon City circa 1867, with Willamette Falls in the background

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  Conveyor belt loading debris onto a barge as part of the Big Pipe Project

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  The weir-type dam at Willamette Falls

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  Detroit Dam, the basin's second tallest

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  The Hawthorne Bridge is the oldest remaining highway structure over the Willamette.

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  The lower deck of the Steel Bridge can be raised independently of the upper deck.

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  The St. Johns Bridge in northwest Portland

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  An aerial view of the 1996 flooding

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  The remains of Vanport City in June 1948

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  The Tom McCall Waterfront Park is named after the Oregon governor who led a cleanup of the river.

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  Osprey are among bird species often seen along the Willamette River.