Whitebark pine, a high elevation tree species found in the western US and Canada, has suffered a dramatic decline across much of its range from mortality caused by mountain pine beetle, exotic blister rust, and fire suppression. Our proposal addresses the dearth of knowledge on fire history and fire-climate interactions in the imperiled whitebark ecosystems. To do this, we propose to expand an ongoing dissertation focused on vegetation dynamics including fire history and severity in the lower elevation Douglas-fir forests and subalpine forests in south-central Idaho. The fieldwork component of this dissertation has been supported by the Sawtooth National Forest Fairfield Ranger District as extremely valuable to informing restoration and management planning. Adding the high elevation whitebark pine component would allow analysis of whitebark pine fires within a landscape context to determine whether fire-climate relationships are similar to or different from the contiguous lower elevation forests. For managers developing long-range plans, this information could help determine where forests may be increasingly vulnerable to climate-change driven shifts in fire regime. Douglas-fir forests in the study area have a mean fire return intervals of 62 years. Superimposed epoch analysis shows that widespread fires occurred during drought years. Based on the fire patterns in the Douglas-fir forests, we hypothesize that during especially dry years, climate-fire interactions connected lower elevation Douglas-fir and high elevation whitebark pine forests through the effects of dry trans-elevation fuel connectivity whereas during wetter periods, fires were smaller and patchier. We also hypothesize that after 1850, as a result of settlement activities including livestock grazing, changes in ground fuels that fire connectivity between low and high elevation forests changed. Field work would be conducted to 1) collect fire history information from dead fire-scarred whitebark, 2) collect stand age structure data from whitebark stands to describe fire extents and effects, and 3) to develop a whitebark climate chronology that reconstructs climate and whitebark response to variation in temperature and precipitation. Deliverables for these projects will include a substantial manager and fire personnel outreach component as well as presentations, publications, and database contributions for the research community. Fire and climate chronologies, maps of fire extent and severity, and analysis of fire severity patterns will be summarized for the Sawtooth National Forest fire and resource managers as a report and in oral presentations to the Fairfield District Office, to fire-fighters during the spring 2016 fire refresher courses, and at the Sawtooth Supervisors Office in Twin Falls. Comparison of whitebark pine fire patterns and tree establishment patterns with those of lower elevation subalpine and Douglas-fir patterns and how those patterns have changed since Euro-American settlement will be presented at national conferences including the 2015 Association for Fire Ecology conference. We will submit a science brief to the Northwest Fire Science Consortium synthesizing results on fire-climate patterns across the Douglas-fir to whitebark landscape. Whitebark pine fire-climate relationships will become a chapter in the PhD dissertation and be submitted as a peer-reviewed journal article. The whitebark pine tree-ring chronology and fire history will be made available to the broader scientific community through NOAAs International Tree-ring Data Bank.