March 27, 2026 — In the late summer of 1805, Meriwether Lewis and William Clark’s Corps of Discovery expedition came upon a camp of Shoshone Indians, who gifted the haggard explorers a meal that raised their spirits.

“This was the first salmon I had seen and perfectly convinced me that we were on the waters of the Pacific Ocean,” Lewis journaled.

He knew that Atlantic salmon moved between ocean and river, inhabiting both saltwater and freshwater environments. The presence of salmon, he thought, surely indicated that he and his group were near their destination on the Pacific coast.

What Lewis did not know was that those fish, caught in the Lemhi River in Idaho, had endured the longest migration of any salmon species on Earth. Certain sockeye salmon climb more than 6,500 feet as they swim from the Pacific upstream through the Columbia River and its tributaries, scaling waterfalls as tall as 20 feet to reach spawning grounds tucked in the snowcapped peaks of central Idaho. Unfortunately for the expedition, the mouth of the Columbia was still more than 600 miles away.

As the explorers followed the river to the west, they encountered an astonishing population of salmon. Historians estimate that at the time, up to 20 million salmon migrated inland in the Pacific Northwest annually

A combination of factors—including hydropower development, habitat loss, pollution, warming waters, overfishing and the introduction of hatchery fish—drove a dramatic decline in salmon population over time. By the late 1970s, those legendary runs had declined by nearly 97 percent. Today, approximately one million salmon and steelhead, an endangered species of trout often grouped with salmon, remain in the region. Seventeen salmon populations are listed as threatened or endangered on the West Coast.

Amid the wide-ranging threats to salmon, conservationists are considering whether a tool known as the fish trap could help protect endangered populations. The traps corral fish into a fenced-off area of the river, where they can then be harvested or released safely. The practice gained popularity among early settlers racing to catch salmon—but in the mid-20th century, following bitter disputes among fishers over the technology, Oregon and Washington banned it.

In 2025, those states authorized three fish traps to operate on the Columbia River—making them the first to harvest commercially in the region in nearly 100 years. The effort was the initial phase of an experiment to test whether the traps could be an economically viable alternative to gillnets, the leading method for catching salmon.

Other experiments, too, have trialed the traps for their economic and conservation potential throughout the past decade. But even as some people see promise in the tool, the work has reopened old wounds in the local fishing community—dredging up long-buried controversies and resurfacing the fish trap’s fraught history.

Read the full article at the Smithsonian Maganzine