A fisherman displays a Lahontan cutthroat trout at Pyramid Lake Calvada Fly Fishing

For the first time since it was declared extinct in the 1940s, a giant cutthroat trout native to northwest Nevada’s Pyramid Lake has spawned naturally this year in its historic home. In the early 1900s, the lake produced the world-record cutthroat trout: 41 pounds. But due to decades of industrialization, the Pyramid Lake strain of Lahontan cutthroat trout — thought to be the largest on earth — gradually disappeared. In 1975, a fish biologist discovered surviving specimens in a mountain creek on the Utah border, and for the past four decades, biologists with the U.S. Fish and Wildlife Service have worked to bring the trout back to Pyramid Lake and to the Truckee River, where they once spawned. “It’s a really significant milestone, because their long-term survival depends on them spawning again in the Truckee River,” said Lisa Heki, complex manager for the Lahontan National Fish hatchery, who has led efforts to conserve this strain since the 1990s. This starts a new chapter in the success story of this trout, Nevada’s state fish, whose champions included Mark Twain, Clark Gable and President Bill Clinton. The trout were long a food staple for the Paiutes, Native Americans who have lived in the giant desert known as the Great Basin for more than 10,000 years. In late April, two Paiute brothers scaled chalky cliffs on their reservation that overlook the Truckee River and discovered giant trout nests, called redds, the size of backyard wading pools, which 25-pound fish had dug in the river’s pebbled bottom using their powerful tails. Once the discovery was reported, U.S. Fish and Wildlife and tribal fisheries biologists swooped in to find nearly 180 such redds. They also confirmed the existence of the first native baby Lahontan cutthroat trout born in this river since before World War II. News of their spawning pushed the trout into the news, as tribe members, conservationists and anglers celebrated the species’ resilience. “To know that this fish is spawning naturally again is epic,” said Doug Ouellette, who has fished Pyramid Lake for 40 years. “Against all odds, this trout is a survivor.”

People didn't realize what they were losing. John Barnes biologist, Trout Unlimited

Cutthroat trout, named for the streaks of crimson underneath their jaws, colonized the cold mountain rivers and lakes of western North America some 4 million years ago, evolving into a dozen different subspecies. The Lahontan subspecies is the biggest, and the strain with the largest fish comes from Pyramid Lake — the end point for snowmelt from the Sierra Nevada that pools in Lake Tahoe and then cascades down the 120-mile Truckee River into the desert of the Great Basin. Until the last ice age ended around 12,000 years ago, much of the Great Basin was flooded under an inland sea called Lake Lahontan. In its waters swam giant minnows and suckerfish called Cui-ui. To eat these fish, Lahontan cutthroat trout grew exceptionally large while still very young. Though the climate warmed, and Lake Lahontan dwindled into the modern-day Pyramid Lake, the fish survived. But as the region quickly industrialized, tens of thousands of Lahontan cutthroat trout were harvested with nets, dynamite and pitchforks. Scores more died from pollution after sawmills and a paper factory in Reno dumped waste into the Truckee River. New dams blocked their migrations. Millions of trout eggs were plucked from streams and either sold to fishermen for use as bait or shipped by rail to other waters around the west in vain attempts to seed other populations of Lahontan cutthroat trout — part of the haphazard start of fish stocking in America. “People didn’t realize what they were losing,” said John Barnes, a biologist for the conservation group Trout Unlimited. Predatory, non-native lake trout were stocked in Lake Tahoe, and they ate baby cutthroats. Into the Truckee River went non-native rainbow trout, and they crossbred with the native cutthroats, ruining their special genes. Soon, non-native trout completely replaced Lahontan cutthroats in Lake Tahoe. But these non-natives could not survive in Pyramid Lake, because its water is about a fifth as salty as the ocean — a condition that the Lahontan subspecies had adapted to. The deathblow for Pyramid Lake’s last Lahontan cutthroat trout came from the 1905 completion of Derby Dam, 36 miles away. The dam sent water south to Nevada’s Carson Valley for homesteading farmers and ranchers. But it also stopped migrating trout that in springs past had swum through downtown Reno, up the Sierra Nevada and sometimes into the tiny creeks that fed Lake Tahoe. And the dam often drained the river so low that trout eggs laid downstream would wither and the embryos inside would die. In 1938, a U.S. Fish and Wildlife Service biologist saw the last run of Lahontan cutthroat trout from Pyramid Lake swim to the base of Derby Dam. Before the water was cut off, killing their eggs, the biologist noted that the nearly 200 Lahontan cutthroat trout weighed an average of about 20 pounds. In the 1940s, the Pyramid Lake strain of Lahontan cutthroat, described later by naturalist Steve Raymond as “the last survivors of an ancient race of super trout,” was declared extinct.

The trout were in that creek. Without it, they would have been completely gone. Robert Behnke trout biologist

The events that led to the trout’s resurrection were both prosaic and incredible. In 1970, the Pyramid Lake Paiute Tribe sued the secretary of the interior to have some of the water that had been diverted by Derby Dam restored. This made the lower Truckee River habitable again to trout and improved Pyramid Lake’s water quality. In an attempt to bring back a semblance of the fish populations that existed before European settlement, the tribe restocked Pyramid Lake with Lahontan cutthroat trout. But with the native strain believed extinct, the tribe introduced one bred from a mix of trout that all lived outside the Pyramid Lake basin. These cutthroats did not grow as large, nor did they spawn in the Truckee River. In 1975, Don Duff, a fish biologist working for the Bureau of Land Management, made a remarkable find. He heard from a rancher that an unusual cutthroat trout lived in a nameless creek up an almost 11,000-foot-tall mountain on the desert border with Utah. Duff climbed this mountain, called Pilot Peak. Near the summit he found water burbling over shale stone. Using a fly-fishing rod, Duff caught several specimens and sent them for identification to his colleague Robert Behnke, the world’s pre-eminent trout biologist. Because they were bound by the tiny stream, they were small in size, but Behnke recognized by their physical features that these trout were survivors of the lost strain of Lahontan cutthroat trout from Pyramid Lake. Somehow, they had been transplanted to the mountain creek, hundreds of miles outside their native range. “They were in that creek,” Behnke said in an interview shortly before his death in 2013. “Without it, they would have been completely gone.” Duff and Behnke researched old fish stocking records. They learned that eggs from Pyramid Lake had been shipped all across the west during the fish-stocking boom of the late 19th and early 20th centuries on the transcontinental railroad. Its tracks ran not far from Pilot Peak. Someone, they concluded, had hauled Pyramid Lake trout up Pilot Peak, stocked them in the creek and forgot about them. This preserved the strain, when all the others in Lake Tahoe, the Truckee River and Pyramid Lake died. “I’ve been persistent over the past 30 years to make sure these fish survive,” said Duff, 76, from his home in Utah. “And I’ll tell you that to my grave.”

The years that these fish were gone from Pyramid Lake is just the blink of an eye in evolutionary time, so it’s no surprise they still have that genetic memory. But it's still amazing. Lisa Heki U.S. Fish and Wildlife Service