<p>Disturbance is a key driver of heterogeneity in mountain landscapes. Historically, the montane ecoregion (i.e., lower elevations where the climate is typically warmer and drier) in Jasper National Park experienced a mixed-severity fire regime with short fire return intervals. However, fire suppression over the previous century has altered the fire return interval, resulting in a significant increase of homogenous forest cover. These changes contributed to an extensive mountain pine beetle (MPB; <i>Dendroctonus ponderosae</i>) outbreak in the park over the previous decade, which impacted up to 90% of lodgepole pine (<i>Pinus contorta</i>). With no previous records of MPB in the park, new research is required to investigate whether the composition and pattern of ecosystems in the montane ecoregion have departed from their historical range of variability due to altered or novel disturbance. In this study, we compare the composition and pattern of landcover in the aftermath of historical, stand-replacing fires (1889 and 1905) and the recent MPB outbreak. We repeated historical survey photographs (captured in 1915) and employed a recently developed workflow for classifying and georeferencing oblique images to produce historical and contemporary landcover maps for a study area in the montane ecoregion. Our results indicate that the MPB outbreak has reduced the area-weighted mean patch size for mature conifer and increased patch complexity in our study area. We conclude that MPB has reintroduced heterogeneity to the montane ecoregion, but also acknowledge that succession in MPB-affected stands will likely differ from post-fire disturbance as the insect only affects pine species. The timing of new compounding disturbances will further influence the recovery and future composition of species in the study area.</p>