The responses of streams to the 1979 Mortar Creek fire in central Idaho provide valuable insights into the extended impact of wildfire on trout habitat. The fire dramatically increased runoff and fine sediment levels and reduced shading and cover from undercut banks and woody vegetation. Although habitat conditions for all life stages of cutthroat trout were adversely affected by fire, these conditions gradually improved over the succeeding 8 years. Habitat for adults is expected to recover most rapidly and to reach optimal conditions about 15 years postfire. Recovery of spawning and rearing habitat will be much slower with suboptimal conditions likely to persist well beyond the first 25 years.