Northwest North America has unique high elevation <i>Picea-Abies</i> forests and parkland classified in British Columbia as the Engelmann Spruce-Subalpine-fir (ESSF) Biogeoclimatic zone. These ecosystems occur on a topographically and climatically complex landscape, juxtaposed with diverse vegetation types including alpine tundra, inland rain forest, dry conifer forest, and grasslands. Spatio-temporal ecosystem disturbance is varied, driven by factors such as climate variation, wildfire, volcanic eruptions, and insect herbivory. A pollen and charcoal record derived from a lake sediment core from the ESSF reveals a unique late-glacial to modern vegetation history progressing from alpine steppe through dry open conifer forest to moist spruce-fir ecosystems, the latter arising only 4600 years ago; late by comparison to other ESSF sites in the region. Repeated disturbance in the mid Holocene by wildfire coupled with volcanic ash deposition and increased climatic variation resulted in recurring <i>Pinus contorta</i>-dominated seral forest stands before cooling and moistening in the late Holocene led to stable <i>Picea-Abies</i> forest. With rapid climate change, changing disturbance regimes, and timber harvest, the management of dry ESSF forests needs to consider that this forest-type could transform into parkland or open seral pine stands, with a high frequency disturbance regime.