The U.S. Forest Service and National Park Service are working together to prepare for the effects of climate change across 3 million hectares in Washington State. This collaborative approach consists of (1) climate change education for all agency employees, (2) assessment of vulnerability of natural resources to climate change, and (3) development of adaptation strategies and tactics to reduce adverse effects of climate change. Direct engagement between research scientists and resource managers through workshops and ongoing dialogue has been the key to this grass-roots process. Adaptation focuses on the Olympic Peninsula (one national forest + one national park) and the North Cascade Range (two national forests + two national parks), directly connecting vulnerability assessments with adaptation options for vegetation, wildlife, fisheries, and hydrology/roads/access. Including regional stakeholders in the science-management partnership has provided for a broad perspective on natural resource issues, as well as support for development and implementation of adaptation in planning and on-the-ground activities. This general approach can be emulated by other agencies that want to begin the process of adapting to climate change across large landscapes.