This study analyzes forest health in the future and exemplifies the uncertainty around potential changing species ranges caused by climate change. Although this analysis could be enhanced by more ecological parameters, our results suggest that MPB populations could establish and spread through the boreal forest from the Yukon interior into northern Saskatchewan by 2100 based on simulations. A more stark observation is that the MPB will no longer be limited by -40oC temperatures in its northern range, and higher proportions of their populations will survive overwinter, which may amplify expansion. Uncertainty exists around the prey-host interaction between the MPB and different species of pine, primarily the switch from lodgepole to jack pine. Implications of this study suggest that there is precedent for forestry managers and policy makers to react sooner than later in reponse to this predicted imminent threat of MPB expansion into the boreal forest.