Collaborative effort to restore Bear Lake cutthroat trout receives national award

The national American Fisheries Society recently awarded top honors to Idaho for conservation efforts in the Bear Lake watershed to help restore the wild Bonneville cutthroat trout fishery there. 

The award recognized community and stakeholder engagement, and partnerships devoted to improving the habitat of this native sport fish. Successful habitat restoration, fisheries science and management resulted in conserving one of the West’s iconic native trout species, as well as bringing back sport fishing opportunity on this ecologically and culturally important native trout. 

This award represents decades of work from a wide range of biologists and landowners from across southeast Idaho and northern Utah working to achieve a remarkable conservation success. 

Wild, naturally spawning Bonneville cutthroat populations increased from just 5 percent to 70 percent of the population in Bear Lake, and allowed anglers to catch and keep wild Bonneville cutthroats from the lake for the first time in more than 20 years.

The Bear Lake Cutthroat Trout Story

Historical declines

Bonneville Cutthroat Trout are native to the ancient Bonneville Basin and occur in portions of Idaho, Nevada, Utah, Wyoming, and Utah. This subspecies of cutthroat trout has faced significant declines, was petitioned for listing under the Endangered Species Act in 1998, and is currently a “species of greatest conservation need” in both Utah and Idaho. One the most important populations of these cutthroat trout occurs within Bear Lake, covering over 70,000 acres and spanning the Utah and Idaho borders.

Bonneville cutthroat's decline in the Bonneville Basin coincided with development in in the basin in the early 1900’s. Habitat loss associated with agriculture, grazing and hydropower development combined with overfishing and introductions of non-native trout drove Bonneville cutthroat trout near extinction. 

By the 1950s, the Bear Lake population was considered close to extinct, and fishery managers started stocking hatchery cutthroat trout to sustain the population. During this time, numbers of wild-origin cutthroat trout in Bear Lake were so low that by 1998, all harvest of wild-origin cutthroat trout was closed, limiting the sport fishery to only hatchery trout.

Important spawning and rearing tributaries to Bear Lake were disconnected by a network of irrigation diversions dams and culverts, blocking much of the spawning and rearing habitat needed to sustain the wild populations. On top of that, non-native brook trout and rainbow trout were common in these tributaries, making things worse from competition and hybridization.

A turning point in 2K

In early 2000s, a coalition of local stakeholders decided it was time to bring back wild cutthroat trout to Bear Lake. During the next 20+ years, biologists from Idaho Fish and Game worked with an extensive range of partners, including the Utah Division of Natural Resources, Trout Unlimited, the US Forest Service, and local landowners and stakeholders, to implement a plan to bring back the Bonnevilles to Bear Lake.

Besides biologist, other partners like the Western Native Trout Initiative helped leverage funding from the National Fish Habitat Partnership program, while energy company PacifiCorp provided extensive funding that supported conservation projects as a result of the Bear River Settlement. 

In 2002, a local working group was established to develop a restoration plan for cutthroat trout in Saint Charles and Fish Haven creeks – two of the lake’s most important spawning tributaries. The working group included irrigation company representatives, local politicians, private landowners, and government agency biologists. 

Planning shifts to action

Screening irrigation diversions and removing blockages to upstream fish migration were major priorities. This group of conservation partners installed fish screens on multiple irrigation diversions in important spawning tributaries like Fish Haven and St. Charles creeks. At the same time, biologists on the Utah side were making gains with new fish screens and habitat restoration on Swan Creek. The screens prevented young cutthroat trout from being lost into the ditches and increased the number of young cutthroat trout reaching Bear Lake, while habitat projects improve conditions for cutthroat trout. In addition, the US Fish and Wildlife Service built dikes in the Bear Lake Refuge to isolate a branch of St. Charles Creek. That helped prevent cutthroat trout from being lost into Mud Lake and the Bear River, instead leading them back into the lake. 

Improving passage to spawning habitat and removing nonnative fish

Until recently, Fish Haven Creek flowed through a concrete flume under State Highway 89. The water speeds across the structure prevented cutthroat trout migrating from Bear Lake from reaching spawning grounds higher in the creek. 

Idaho Fish and Game replaced the flume with a fish-friendly design, reconnecting this major spawning tributary to Bear Lake. This was combined with chemical treatment in 2009 to remove nonnative rainbow and brook trout in the creek. To date, Fish Haven Creek is absent of nonnative trout, and Bonneville cutthroat trout are thriving there. 

In 2019-2020, Fish and Game funded studies by the USGS-Idaho Coop Fish and Wildlife Research Unit at the University of Idaho. The study investigated the migratory behavior of cutthroat trout in these tributaries, and produced a new understanding of how cutthroat trout were using the tributaries, and what factors were driving their distribution, migration patterns and survival. The study also combined multiple years of gillnetting data from lake to evaluate whether the Bear Lake’s wild cutthroat population could support any sport fishing harvest. 

A brighter future for cutthroat

These extensive conservation efforts have significantly improved the cutthroat trout population in Bear Lake. Over 30 fish screens on 10 different streams are now in place on irrigation diversions, while 3,800 acres has been protected in conservation easements. 

Removing nonnative brook trout and rainbow trout from Fish Haven Creek as well as Swan Creek on the Utah side has improved the spawning success of the lake’s cutthroat trout. Spawning surveys in Fish Haven Creek after the barrier removal project show that hundreds of migratory cutthroat trout are now spawning in this tributary, and more migrating juvenile trout are reaching Bear Lake. 

Going native

Twenty years ago, the population of cutthroat trout in Bear Lake was almost exclusively hatchery-raised fish. However, conservation and fish management changes have markedly improved the Bear Lake fishery.  In 2002, the wild-origin cutthroat trout in Bear Lake surveys was only 5%, while in 2017, it had increased to 70%. Wild-origin cutthroat trout in Bear Lake now make up the majority of cutthroat trout in the lake. 

In response, the Idaho Fish and Game Commission adopted new fishing regulations in 2022 that allowed anglers to harvest of both hatchery- and wild-origin cutthroat trout for the first time in 24 years.

Bonneville cutthroats still face challenges in many waters through the Bonneville Basin, and their populations are not doing well everywhere. But at least in one corner of the West, we can see what’s possible when local stakeholders and biologists come together to do good things for native trout and for the communities they swim through.