The Western Mountain Initiative (WMI), a consortium of research groups in the Western United States, focuses on understanding and predicting responses-especially sensitivities, thresholds, resistance, and resilience-of mountain ecosystems to climatic variability and change (Peterson et al. 2012). The WMI addresses how climatic variability and change influence forest processes, disturbance dynamics, hydrologic changes, and hydroecological interactions in five bioregions: Pacific Northwest, Sierra Nevada, Northern Rocky Mountains, Central Rocky Mountains, and Southern Rocky Mountains. A guiding theme of WMI research is understanding the linkages among these processes. This focus on linkages (e.g., climate change affects disturbance regimes, hence vegetation, hence erosion) and the depth and breadth of place-based knowledge represented by this work contribute to multisite regional comparisons.