The U.S. Forest Service (USFS) and National Park Service (NPS) have highlighted climate change as an agency priority and issued direction to administrative units for responding to climate change. In response, the USFS and NPS initiated the North Cascadia Adaptation Partnership (NCAP) in 2010. The goals of the NCAP were to build an inclusive partnership, increase climate change awareness, assess vulnerability, and develop science-based adaptation strategies to reduce these vulnerabilities. The NCAP expanded previous science-management partnerships on federal lands to a larger, more ecologically and geographically complex region and extended the approach to a broader range of stakeholders. The NCAP focused on two national forests and two national parks in the North Cascades Range, Washington (USA), a total land area of 2.4 million ha, making it the largest science-management partnership of its kind. The NCAP assessed climate change vulnerability for four resource sectors (hydrology and access; vegetation and ecological disturbance; wildlife; and fish) and developed adaptation options for each sector. The NCAP process has proven to be a successful approach for implementing climate change adaptation across a region and can be emulated by other land management agencies in North America and beyond.