IntroductiondSeattle Mountain Rescue (SMR) is a nonprofit, volunteer organization that provides mountain rescue services in King County, Washington. This study analyzed the medical care provided by SMR over 14 y to understand the challenges in patient care in the region and to perform data collection and monitoring.MethodsdA retrospective review of mission reports submitted from 2004 to 2017 was conducted. Date, location, demographics, activity, callout reason, chief complaint, treatments provided, extraction means, and helicopter utilization were analyzed. Data are presented as mean±SD, with range as appropriate, unless otherwise noted. Linear regression was used to estimate changes in mission volume over time.ResultsdThere were 552 missions involving 756 subjects during the study period. Mission totals increased by 4 (95% CI 2e6, P<0.001) per year. Four locations accounted for 38% of mission volume. Subject age was 36±18 y, and 59% of subjects were male. The most common activity leading to rescue was hiking (80%). Injuries or illness precipitated 58% of callouts, whereas lost, stranded, or overdue subjects comprised 40%. For subjects requiring medical treatment, 81% involved a traumatic injury, 64% were packaged in a litter, and 35% required splinting.ConclusionsdThe frequency of mountain rescue missions in King County, Washington, has increased in the past 14 y, with traumatic injuries most frequently requiring medical care. Missing data were common in most categories, and nonstandardized reports challenged research efforts. This study provides a baseline for future research and data collection and adds to the literature regarding the medical care provided during mountain rescue incidents.