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Big Hole River in the fall

Trout Management in Southwest Montana

FWP is launching several research efforts in response to trout declines in the Big Hole, Beaverhead and Ruby rivers. In partnership with Montana State University, the following efforts will examine fish mortality, recruitment and health.


Fish mortality study - A mortality study on the Big Hole, Beaverhead and Ruby rivers, as well as the Madison River, will include tagging adult fish to assess how flows, water temperatures, angling and disease influence survival. This study would also help measure the success of adaptive management plans for the Big Hole, Beaverhead and Ruby rivers that propose adjustments to fishing regulations in response to changes in trout populations.

Juvenile fish study - A juvenile fish study will focus on developing a better understanding of trout recruitment and the relative contributions of tributary spawning areas to mainstem trout populations. This would include using otolith microchemistry to examine fish movements and age, as well as geographical origins of juvenile fish.

Fish health study - A fish health study will examine the level that disease is impacting fish populations in the Big Hole, Beaverhead and Ruby rivers. This would include testing for novel pathogens and determining better ways to routinely sample fish for disease in the future.

Fish Health Monitoring - FWP is increasing fish health monitoring and reporting resources on the Big Hole, Beaverhead and Ruby rivers, including the new web portal

Fishing Regulation Changes

New angling restrictions were adopted on the Big Hole, Beaverhead and Ruby rivers:

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Field Trips

Beaverhead, Ruby, & Big Hole

Montana's cold water fisheries fall under the stewardship of Montana biologists, Matt Jaegar and Jim Olsen. Join host, Lauren Karnopp in the first series of Field Trips.