A forest fire followed by an intense convectional rainstorm caused a 100-year flood in the Beaver Creek drainage. This study documented changes in resident trout populations and use of the stream by adfluvial spawning fish. Two months after the event trout populations in the impacted portion of the stream were nearly eliminated. Within two years, numbers and biomass of rainbow trout had increased to 55% and 51% greater, respectively, than before the event. Rapid recovery of the rainbow trout population resulted from large spawning runs from the Missouri River.