The core distribution of Rocky Mountain bristlecone pine, Pinus aristata Engelm., extends from central Colorado into northern New Mexico, with a disjunct population on the San Francisco Peaks in northern Arizona. Populations are primarily at high elevations and often define the alpine treeline; however, the species can also be found in open mixed conifer stands with ponderosa (Pinus ponderosa Lawson & C. Lawson) and/or pinyon (Pinus edulis Engelm.) pines in some locations. On dry, exposed sites the stands are open and sparse and Rocky Mountain bristlecone (hereafter referred to as bristlecone) is commonly the only species present. The combination of the pine's adaptive traits with infrequent disturbance has enabled trees on these sites to attain ages of over 2,500 years. These same traits and conditions, which contribute to a long generation time, will inevitably hinder the ability of bristlecone pine to adapt to novel anthropogenic stresses such as climate change and infection by the non-native pathogen (Cronartium ribicola) that causes the lethal disease white pine blister rust (WPBR). Infection of bristlecone pine by C. ribicola was first documented in the field in 2003 in south-central Colorado. Rapid climate warming and the associated increase in mountain pine beetle activity are also affecting these high elevation ecosystems. These threats and the species' unique aesthetic and ecological roles make bristlecone pine a species of conservation interest. Blister rust invasion is relatively recent compared to the generation time of bristlecone pine, thus we still have a window of opportunity to gain and utilize new knowledge of this species and their ecosystems under natural conditions and develop proactive conservation strategies.