Discover the 12 Longest Rivers in Oregon

Oregon’s epic landscape is incredibly diverse, ranging from the temperate rainforests of the Oregon Coast Range to the glaciated Cascade Mountains and the high desert of the Columbia Plateau. Its mighty rivers course through the state’s many different regions, even the drier ones. Oregon is home to some incredibly long rivers, including the seventh- and ninth-longest rivers in the United States. This article explores the 12 longest rivers in Oregon, including their location and the amazing wildlife living in and around them.

12. Nehalem River

The Nehalem River begins in the Tillamook State Forest, which is in the Northern Oregon Coast Range. It is home to several fish species including the steelhead trout, Chinook salmon, and coho salmon. Additionally, the Nehalem River is an important habitat for the North American river otter and the North American beaver.

11. Powder River

The Powder River begins at the confluence of McCully Fork and Cracker Creek near Sumpter, OR. It is a tributary of the mighty Snake River, one of the longest rivers in Oregon. Some of the fish species living in the Powder River include the rainbow trout, bull trout, and brook trout.

10. Grande Ronde River

The Grande Ronde River begins in the Elkhorn Mountains, a subrange of the Blue Mountains in eastern Oregon. It drains part of the Columbia Plateau, an arid region between the Cascade Mountains and the Rocky Mountains. The Grande Ronde River is home to some amazing fish species including Chinook salmon, steelhead trout, and bull trout.

9. Willamette River

The Willamette River begins at the confluence of the Middle Fork Willamette River and Coast Fork Willamette River near Eugene, OR. It is a major tributary of the Columbia River. The Willamette River flows through the Willamette Valley, a highly fertile agricultural region. It is home to several amazing fish species including the Chinook salmon, coho salmon, and coastal cutthroat trout.

8. Malheur River

The Malheur River begins in the Strawberry Mountains, a subrange of the Blue Mountains in eastern Oregon. It is a tributary of the mighty Snake River, one of the longest rivers in Oregon. The Malheur River is home to several native fish species including the northern pikeminnow, mottled sculpin, and redband trout.

7. Rogue River

The Rogue River begins in Crater Lake National Park and flows through the Cascade, Klamath, and Oregon Coast mountain ranges. It is an important habitat for several Salmonids including the steelhead trout, coho salmon, and Chinook salmon. The Rogue River is also home to Pacific lamprey, an ancient parasitic fish.

6. Deschutes River

The Deschutes River begins at Little Lava Lake in the Cascade Mountains and drains the dry, eastern slopes of the mountains. It is one of the many tributaries of the mighty Columbia River. Some of the amazing fish species living in the Deschutes River include the Columbia River redband trout, sockeye salmon, and coho salmon.

5. John Day River

The John Day River begins in the Strawberry Mountains, a subrange of the Blue Mountains of eastern Oregon. It empties into the mighty Columbia River east of Biggs Junction, OR. The John Day River is the longest undammed river in Oregon. It is home to several amazing animals including the bull trout and steelhead trout, both of which are listed as threatened under the U.S. Endangered Species Act.

4. Klamath River

The Klamath River begins at Upper Klamath Lake in arid Eastern Oregon. It flows through the Cascade Mountains and Klamath Mountains before emptying into the Pacific Ocean in Northern California. The Klamath River is an important habitat for anadromous fish, meaning fish that migrate from one body of water to another. It is home to Chinook salmon, coho salmon, and steelhead trout populations.

3. Owyhee River

The Owyhee River’s name is an alternative spelling of Hawaii, and it comes from three Native Hawaiian men who worked as trappers for the Northwest Company and were sent to explore the river. At 346 miles long, it is the third-longest river in Oregon. The Owyhee River flows through the arid Owyhee Plateau of Eastern Oregon, one of the most remote places in the United States. The Owyhee Plateau has deep, dramatically steep canyons carved by the Owyhee River. Due to its remoteness, the Owyhee River is home to an abundance of wildlife. Some of the many animals living in and around the river include the rainbow trout, greater sage-grouse, and pronghorn.

2. Snake River

The Snake River is the second-longest river in Oregon and the ninth-longest River in the United States. It flows 1,078 miles from the Absaroka Range, a sub-range of the Rocky Mountains in northwestern Wyoming, to the Columbia River in southeastern Washington. The Snake River forms a large portion of Oregon’s border with Idaho. Some of the amazing animals living in the Snake River are the Oregon chub, steelhead trout, and Chinook salmon.

1. Columbia River

The mighty Columbia River is not only the longest river in Oregon, but the seventh-longest in the United States. It begins at Columbia Lake in southern British Columbia, a Canadian province, then flows through Washington and Oregon before emptying into the Pacific Ocean. Much of Oregon’s border with Washington is formed by the Columbia River. As the river snakes its way between the two states, it flows through the massive Columbia River Gorge, an 80-mile-long canyon that is up to 4,000 feet deep. The Columbia River is home to some amazing animals including the coho salmon, sockeye salmon, white sturgeon, and North American river otter.

Summary Table of the 12 Longest Rivers in Oregon

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