FWP responds to brown trout detection in Flathead River
July 14, 2025 by Moosetrack Megan
Fishing
| KALISPELL — Montana Fish, Wildlife & Parks has confirmed the detection of a Montana Fish, Wildlife & Parks has confirmed the detection of a non-native brown trout in the Flathead River upstream of Pressentine Fishing Access Site near Evergreen, and anglers are encouraged to submit any additional brown trout caught within the drainage. To assess the extent of the issue, FWP is deploying environmental DNA (eDNA) sampling technology to detect any additional presence of brown trout in the Flathead River and tributaries This method will help identify areas where brown trout may be present, guiding future management actions. FWP strongly urges anglers who catch a brown trout in the Flathead River or its tributaries to kill the fish immediately and report the catch to the FWP Region 1 office at 406-752-5501. Anglers are asked to provide the fish as well as the location and date of the catch to assist in monitoring efforts. Brown trout can harm native trout species, such as bull trout and westslope cutthroat trout, by outcompeting them for resources and preying on juvenile fish. “Protecting our native trout populations is a priority,” said FWP Regional Fisheries Manager Mike Hensler. “Brown trout pose a threat to native species in the Flathead drainage, and we need the public’s help to manage this invasive species.” Moving live fish from one waterbody to another is illegal. The illegal introduction of non-native fish and other invasive species can have devastating ecological, recreational and economic impacts. These species disrupt aquatic ecosystems by altering food webs, reducing biodiversity, and threatening native species critical to Montana’s fisheries. Brown trout are identified by their golden brown to yellow-brown color, with dark spots often surrounded by lighter halos, and sometimes with red or orange spots. Source: Montana FWP |
