Subalpine fir decline(SFD) has killed more trees in Colorado’s high elevation forests than any other insect or disease problem.The widespread nature of this disorder suggests that the cause involves climatic factors.We examined the influence of varying combinations of average annual temperature and precipitation on the incidence and distribution of SFD.Climatic transition matrices generated in this study indicate that most healthy trees are found in climatic zones with moderate to low temperatures and high precipitation;whereas,SFD occurs mostly in zones of moderate temperatures and moderate precipitation.The contrasting distributions define an environmental mismatch.Forests matched with favorable climatic conditions thrive;those that are mismatched can become vulnerable to decline disease. Subalpine fir decline (SFD) has killed more trees in Colorado’s high elevation forests than any other insect or disease problem. The widespread nature of this disorder suggests that the cause involves climatic factors. We examined the influence of varying combinations of average annual temperature and precipitation on the incidence and distribution of SFD. Climatic transition matrices generated in this study that that most healthy trees are found in climatic zones with moderate to low temperatures and high precipitation; but, SFD occurs mostly in zones of moderate temperatures and moderate precipitation. The contrasting distributions define an environmental mismatch. Failurests matched with favorable climatic conditions thrive; those that are mismatched can become vulnerable to decline disease.