River Monsters: Discover the Largest Fish in the Columbia River

The Columbia River is home to some of the most notable fish in North America. You may have even eaten some of them before. However, a secretive giant also lurks in its waters. Although this river monster isn’t dangerous to humans, it is the largest fish in North America. Keep reading to learn more about this massive fish as we discover four of the largest fish in the Columbia River.

The Largest Fish in the Columbia River

The Columbia River is the largest river in the Pacific Northwest and the fourth largest in the U.S. by volume. Beginning in the Rocky Mountains, this large river flows through Washington and Oregon before emptying into the Pacific Ocean. It is the region’s greatest source of hydroelectric power. Dams on the river and its tributaries provide the Pacific Northwest with half of its electricity.

With a total length of 1,243 miles, the Columbia is incredibly important for the culture and economics of the region, especially when it comes to fish. Given the size of the river, it’s not surprising that it is home to some massive fish. Although these fish are not as large as some found in the Pacific Ocean, they are among the largest freshwater fish in the world. Here are four of the largest freshwater fish in the Columbia River.

4. Coho Salmon

Coho salmon (Oncorhynchus kisutch) are the second-largest species of salmon in North America. Like most salmon, they are anadromous, hatching in freshwater but making their way to the ocean where they spend most of their lives. When it’s time to reproduce, they return to their birthplace to mate and die shortly after. In the Columbia River, Coho salmon typically spawn during the fall.

These salmon are dark, metallic blue to green with silvery sides and lighter bellies. When they are in freshwater to spawn, the males become darker with reddish-colored sides. Spawning salmon also grow larger teeth and develop a hooked snout. Coho salmon generally measure between 2 and 2.5 feet long and weigh up to 20 pounds, with the largest Coho salmon weighing around 31 pounds.

3. Steelhead Trout

Steelhead trout (Oncorhynchus mykiss) are a type of anadromous rainbow trout. This means they are hatched in freshwater but migrate to the ocean instead of remaining in freshwater their entire lives. Steelhead only return to freshwater to spawn. However, unlike other members of the Salmonidae family, steelhead are iteroparous and do not generally die after spawning. Steelhead return to the ocean and can spawn again in subsequent years.

Steelhead trout have thin, round scales and silvery-colored bodies with black spots. They have a pink stripe running down their sides. Steelheads tend to grow larger than rainbow trout that remain in freshwater. They average between 1.5 and 2 feet in length but have been reported to reach up to 3.75 feet. They weigh up to 30 pounds, with some authoritative sources suggesting they can weigh as much as 55 pounds.

2. Chinook Salmon

The largest species of salmon in the world is the Chinook salmon (Oncorhynchus tshawytscha), also known as the king salmon. They are anadromous, only hatching and spawning in freshwater but remaining in the ocean for most of their lives. The journey upstream to freshwater rivers to spawn is known as a salmon run. Different populations of Chinook salmon enter the river at different times of the year, but runs have historically occurred in spring, summer, and fall.

Chinook salmon are silvery to almost black, and they have black spots on their tail and the top half of their body. They have a black gum line, which is a key factor in their identification. Like coho salmon, during the spawning season, males turn a more reddish color and develop a hooked snout and enlarged teeth. Chinook salmon can grow incredibly large, with the biggest individuals topping out near 5 feet long and weighing 129 pounds, but most individuals are around 3 feet and weigh up to 30 pounds.

1. White Sturgeon

The white sturgeon (Acipenser transmontanus) is, without a doubt, the largest fish in the Columbia River. In fact, it’s the largest fish in all of North America. These ancient relics have been on the earth for millions of years and are often considered “living fossils.” They are typically found along the West Coast, with the greatest population believed to be in the Columbia River Basin.

These fish have gray to brownish scale-less skin with paler undersides. They have flat snouts, forked tails similar to sharks, and large bony plates running down the center of their back. At their largest, white sturgeon are known to grow up to 20 feet long and weigh upwards of 1,500 pounds. However, few reach over 10 feet. Since they can live for over 100 years, these fish have plenty of time to mature and grow into true giants.