Comprehensive sampling of curlleaf mountain-mahogany (Cercocarpus ledifolius) on 41 sites in five States allowed an assessment of postfire population dynamics, differences in regeneration patterns, and critical events in stand regeneration. Historical accounts of fire, fire history studies, and early photographs provided historical perspective and contributed to interpretations. The combined quantitative and historical evidence strongly suggests that before European settlement, fire significantly influenced mahogany in the Northern Rockies by restricting its development. A reduction of fire periodicity and size following EuroAmerican settlement apparently allowed mahogany seedlings to regenerated far in excess of former levels. The absence of fire for long periods has resulted in great variation in structure of mahogany stands. Many stands are in a declining condition because the absence of fire has allowed them to reach advanced stages of succession. In some areas, closure of mahogany crowns, excessive litter accumulation, and competition from other vegetation are inhibiting regeneration. In other areas, young vigorous mahogany predominate. These wide differences in stand conditions suggest different management strategies. Many mahogany communities would respond positively to fire, whereas others would not. Management implications are given.