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Willamette River

geography Maturity 7-9

The Willamette is a big river.

Willamette River at Molalla SP eb.jpg
Willamette River at Molalla SP eb.jpg
It is in Oregon. It flows north to a larger river. Many fish live in the water.
Osprey mg 9605.jpg
Osprey mg 9605.jpg
It is a busy place. Do you like rivers?

41 words

The Willamette is a big river.

Willamette River at Molalla SP eb.jpg
Willamette River at Molalla SP eb.jpg
It is in Oregon. It flows north to a larger river.
Wpdms shdrlfi020l willamette valley.jpg
Wpdms shdrlfi020l willamette valley.jpg

Many people live near the water. They live in cities like Portland and Salem. The river flows through a wide valley. This land is good for farms.

Lots of fish live in the river. You can see salmon and trout.

Osprey mg 9605.jpg
Osprey mg 9605.jpg
Birds like the osprey also live here.

Many bridges cross the water. Some are for cars. Other bridges are for people to walk or ride bikes.

It is a very busy and beautiful place.

104 words

The Willamette River is a major river in Oregon.

Wpdms shdrlfi020l willamette valley.jpg
Wpdms shdrlfi020l willamette valley.jpg
It flows north through a wide area called a valley. This valley sits between two mountain ranges. To the west is the Coast Range. To the east is the Cascade Range.
Willamette River at Molalla SP eb.jpg
Willamette River at Molalla SP eb.jpg
The river flows into the Columbia River. Many people live near the water. Two big cities are Salem and Portland. Portland sits right where the river meets the Columbia.
Pan Voyager moored in the Williamette.jpg
Pan Voyager moored in the Williamette.jpg

The river valley has very rich soil. This makes it a great place for farms. Long ago, huge floods changed the land. These floods brought rocks from far away. Some of these rocks are very big boulders.

Erratic rock Oregon.JPG
Erratic rock Oregon.JPG
Today, the river is home to many fish. You can find 60 different species there. Salmon and trout are common to see. Many bridges cross the river for cars and bikes.
Oregon Route 34 1717.JPG
Oregon Route 34 1717.JPG
Some people also use ferries to cross the water.

166 words

The Willamette River is a major river in the state of Oregon.

Wpdms shdrlfi020l willamette valley.jpg
Wpdms shdrlfi020l willamette valley.jpg
It flows through a wide area known as the Willamette Valley. This valley sits between two mountain ranges. The Coast Range is to the west. The Cascade Range is to the east. The river flows north toward the Columbia River. It provides about 12 to 15 percent of the Columbia's water flow.
Pan Voyager moored in the Williamette.jpg
Pan Voyager moored in the Williamette.jpg

The river's path has changed many times over millions of years. Plate tectonics first helped create the valley about 35 million years ago. Later, volcanoes and erosion changed the land again. Huge floods happened at the end of the last ice age. These were called the Missoula Floods. They were so large that they could fill the valley with deep water.

Erratic rock Oregon.JPG
Erratic rock Oregon.JPG
These floods even carried icebergs and big rocks from Montana. These rocks are called glacial erratics because they do not belong in Oregon.
Wilhamut.1.JPG
Wilhamut.1.JPG

People have lived in this area for a very long time. Humans first arrived in the watershed over 10,000 years ago. Many tribal villages once stood along the lower river. In the 1800s, many pioneers traveled the Oregon Trail to reach this valley. They came because the soil is very rich for farming. The river was also a great way to travel by boat. However, a place called Willamette Falls acted as a big barrier for boats.

Oregon City and Willamette Falls, 1867.jpg
Oregon City and Willamette Falls, 1867.jpg

Today, the river is a busy place for many different things. About 30 different bridges cross the main river. Some bridges are only for cars, while others are for bikes or trains. There are also ferries that carry people and vehicles across the water.

Oregon Route 34 1717.JPG
Oregon Route 34 1717.JPG
Since 1900, more than 15 large dams have been built here. Many of these dams help make electricity. They also help stop floods and create places for fun.
USACE Detroit Dam Oregon.jpg
USACE Detroit Dam Oregon.jpg
The river is home to 60 different kinds of fish. You can find many types of salmon and trout living in its waters.
Osprey mg 9605.jpg
Osprey mg 9605.jpg

The Willamette River connects many important cities and places. It flows through cities like Salem, Eugene, and Albany. The largest city, Portland, sits right where the river meets the Columbia.

SteelBridgePano1.jpg
SteelBridgePano1.jpg
Near Portland, the river splits into two different paths. One path goes around Sauvie Island. The other path is called the Multnomah Channel.
Multnomah Channel (Multnomah County, Oregon scenic images) (mulDA0081a).jpg
Multnomah Channel (Multnomah County, Oregon scenic images) (mulDA0081a).jpg
This channel is a smaller way for water to flow. The river is a vital part of life in northwestern Oregon.

431 words

The Willamette River is a major river in the state of Oregon.

Wpdms shdrlfi020l willamette valley.jpg
Wpdms shdrlfi020l willamette valley.jpg
It is a primary tributary of the Columbia River. The Willamette provides between 12 and 15 percent of the Columbia's total water flow. The river's main stem lies entirely within northwestern Oregon. It flows northward through a large basin called the Willamette Valley. This valley sits between the Coast Range to the west and the Cascade Range to the east. The river and its many tributaries support a massive drainage basin. This basin covers about 12 percent of the total area of Oregon.
Willamette River at Molalla SP eb.jpg
Willamette River at Molalla SP eb.jpg

The geography of the river was shaped by many geological processes. About 35 million years ago, plate tectonics began creating the basin. The Farallon Plate subducted beneath the North American Plate. This movement created a forearc basin. The oldest rocks in this area are the Siletz River Volcanics. Later, volcanic activity and erosion continued to change the landscape. About 15 million years ago, basalt from the Columbia River Basalt Group flowed across the northern basin. This lava covered parts of the Tualatin Mountains with up to 1,000 feet of material.

Erratic rock Oregon.JPG
Erratic rock Oregon.JPG

At the end of the last ice age, massive floods changed the valley again. These were the Missoula Floods, which occurred between 15,500 and 13,000 years ago. These floods originated from Glacial Lake Missoula in Montana. Each flood discharge exceeded the annual discharge of all modern rivers combined. The floods filled the Portland region with water up to 300 feet deep. This created a temporary body of water known as Lake Allison. These floods also carried large icebergs and rocks into the valley. These are called glacial erratics because they are not native to the area.

Wilhamut.1.JPG
Wilhamut.1.JPG

The Willamette Valley is a very fertile agricultural region. This fertility comes from rich sediments deposited by ancient flooding. The area also receives prolific rainfall from the western side of the Cascades. Because of this, many 19th-century pioneers traveled the Oregon Trail to reach the valley. Humans have lived in this watershed for over 10,000 years. Indigenous peoples once lived in many tribal villages along the lower river. Today, the valley contains two-thirds of Oregon's population. This includes the state capital, Salem, and the largest city, Portland.

Pan Voyager moored in the Williamette.jpg
Pan Voyager moored in the Williamette.jpg

Modern life along the river involves many different types of transportation. There are approximately 30 different bridges that cross the main stem. Some bridges carry motorized vehicles, while others are for bicycles and pedestrians. Several bridges are used exclusively for rail traffic. Ferries also provide crossings for cars, trucks, and motorcycles. For example, the Wheatland Ferry runs between Marion and Polk counties. The river is also used for navigation, especially near Portland's industrial areas. The main channel is deep and serves as a primary conduit for the harbor.

Oregon Route 34 1717.JPG
Oregon Route 34 1717.JPG

Since 1900, humans have built more than 15 large dams in the drainage basin. Thirteen of these dams are operated by the U.S. Army Corps of Engineers. These structures serve several important purposes. They produce hydroelectricity and maintain reservoirs for recreation. They also help to prevent flooding in the valley. However, the river and its tributaries face challenges from pollution and habitat changes. Despite this, the river supports 60 different fish species. This includes many important species of salmon and trout.

USACE Detroit Dam Oregon.jpg
USACE Detroit Dam Oregon.jpg

The river's path is not a straight line. It meanders generally northward toward the Columbia River. The river has two major deviations at Newberg. At one point, it turns sharply east before turning north again. Near the mouth of the river, it splits into two channels. One is the main navigational channel. The other is a smaller distributary called the Multnomah Channel.

Multnomah Channel (Multnomah County, Oregon scenic images) (mulDA0081a).jpg
Multnomah Channel (Multnomah County, Oregon scenic images) (mulDA0081a).jpg
This channel is about 10 miles long and 1,000 feet wide. The river's flow is also affected by the tides of the Pacific Ocean. Near Portland, the river can actually experience reverse flows during certain tides.
Osprey mg 9605.jpg
Osprey mg 9605.jpg

671 words
🖼️ Images & Media (18)
File:Pan Voyager moored in the Williamette.jpg
Pan Voyager moored in the Williamette.jpg
File:Multnomah Channel (Multnomah County, Oregon scenic images) (mulDA0081a).jpg
Multnomah Channel (Multnomah County,...
File:Oregon_Route_34_1717.JPG
Oregon_Route_34_1717.JPG
File:Erratic rock Oregon.JPG
Erratic rock Oregon.JPG
File:Wpdms shdrlfi020l willamette valley.jpg
Wpdms shdrlfi020l willamette valley.jpg
File:Willamette River at Molalla SP eb.jpg
Willamette River at Molalla SP eb.jpg
File:Wilhamut.1.JPG
Wilhamut.1.JPG
File:Oregon City and Willamette Falls, 1867.jpg
Oregon City and Willamette Falls, 1867.jpg
File:Conveyor belt for Big Pipe project - Portland, Oregon.JPG
Conveyor belt for Big Pipe project -...
File:Oregon City Willamette Falls Paper Mill.jpg
Oregon City Willamette Falls Paper Mill.jpg
File:USACE Detroit Dam Oregon.jpg
USACE Detroit Dam Oregon.jpg
File:HawthorneBridge-Pano.jpg
HawthorneBridge-Pano.jpg

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