Cooney Creek, Swan Valley, Condon, Montana, USA A Brook Trout assertively defending territory against encroaching Westslope Cutthroat Trout in the evening

Cooney Creek, Swan Valley, Condon, Montana, USA A Brook Trout persistently expelling a Westslope Cutthroat Trout out of its territory in the evening

Cooney Creek, Swan Valley, Condon, Montana, USA A Brook Trout vigorously chasing away an intrusive Westslope Cutthroat trout several times in the evening

Cooney Creek, Swan Valley, Condon, Montana, USA A Brook Trout circling a pair of westslope cutthroat trout before driving both rivals out of its territory in the evening

Cooney Creek, Swan Valley, Condon, Montana, USA A Brook Trout forages at the surface, then disperses a rival Westslope Cutthroat Trout from its territory before swimming up to and around the camera