Climate change may influence wildlife populations more than any management challenge in recent history. Within the past year numerous reports and papers have come out relative to wildlife and climate change. Now is the time to start addressing the impacts of these changes in Montana. This paper discusses some of the ways climate change may impact big game populations relative to recent climate data sets for Montana. Length of growing season, winter severity, time of spring green-up, summer heat, drought, all may have direct or indirect impacts on wildlife populations. Indirect impacts include disease and disease vectors. Recent declines in some of our big game species may be attributed in part to climate change. Hunting quotas and seasons have been modified to ameliorate some of the population changes. We must be proactive in assessing the impacts of climate change on Montana wildlife populations in order to apply adaptive management