The Columbia River was once a wild river, full of salmon. The river runs through the U.S. states of Oregon and Washington. It also winds through the Canadian province of British Columbia.

These days, the 1,954-kilometer (1,214-mile) river is much calmer than it used to be. Dams have chopped the once mighty Columbia into a series of peaceful lakes and ponds. As water passes through a dam, blades inside create electricity. This slows the water.

The Bonneville Dam was built in 1938. It was the first major artificial change to the Columbia River. The Bonneville Dam is actually a series of several dams. These dams link Oregon and Washington. The dam was built for two reasons. It provides electricity to people who live nearby, and it makes the river easier for boats to navigate.

Grand Coulee Holds A Record

Other dams were built on the Columbia, including the huge Grand Coulee Dam in Washington. As of 2022, it is the largest concrete structure in the United States, and there are 14 major dams on the main part of the Columbia River.

The dams on the Columbia create more than half of the area's electricity. The dams also make it possible for boats to travel 748 kilometers (465 miles) up the Columbia River, from the Pacific Ocean all the way to Idaho.

Salmon Runs

The dams have caused trouble for the river's ecosystem, especially the Columbia's salmon. Jeff Hickman used to be an organizer for the Sierra Club, which works to protect the environment. He said the area was once very healthy. "It had the largest population of fish on the planet," Hickman said.

The Columbia was once a fast-moving waterway. The dams broke it into smaller pieces, with slower currents and warmer water. Hickman said the warmer temperature puts more stress on migrating fish. It also means there are more predators that eat those fish.

The Columbia River Inter-Tribal Fish Commission represents the region's Native American population. Bob Heinith is their water program coordinator. Heinith says the dams prevent fish from getting upstream. He says about two-thirds of the area that fish can live in has been cut off by the dams.

Fish Ladders

Fish ladders were built at many of the dams. These allow salmon to get past the dams and continue upstream to lay eggs. The fish ladders are like steps that water flows down. They create a series of shallow waterfalls. Dams are often impossible for fish to pass, though the salmon are able to get upstream using these fish ladders.

Once the fish are born, they must head back downstream to the ocean. The Bonneville Power Administration is the group that handles electricity made by the dams. It has tried to help the young fish get back downstream. The dams' blades have been made less dangerous to fish. There is also a path that allows the fish to swim around the blades entirely.

During salmon migrations, water is spilled over the top of the dams. This imitates how the river used to flow. The dams create less electricity, but it is better for the fish.

Sea Lions

Sea lions have learned that they can travel up the Columbia River from the Pacific Ocean. There are many salmon at the base of Bonneville Dam. The sea lions can feast on them there. To deal with the problem, the U.S. Army Corps of Engineers and the states of Washington and Oregon scare away the sea lions with firecrackers and rubber bullets.

The Sierra Club says that the Bonneville Power Administration's efforts have helped. They wonder if the dams are worth all the extra time and money, though.

"There's no doubt it's helping, but you have to weigh out the costs," Hickman says.