Bull Trout are Montana’s largest native predator fish species and aggressive hunters. The species has been protected in Montana since 1998 under The Endangered Species Act. Bull Trout are extremely sensitive to change. Variable water temperatures or changes in diet can have a large impact on these fish. There are only a few places left where you can legally target these fish by strict regulations. Montana Fish Wildlife and Parks takes angling for these fish very serious and for good reason. With help from responsible anglers, Montana Biologists can study Bull trout more closely.