Carkeek 12 Hour

The Carkeek 12-Hour is a challenging trail running event held annually at Carkeek Park in Seattle, Washington. Celebrating its 19th edition in 2025, the race offers both 12-hour and 6-hour options on a 1.93-mile loop course featuring 436 feet of elevation gain per lap, including rolling trails and steep stairs with scenic views of Puget Sound. Known as one of the toughest 12-hour races, it embraces a festive Halloween atmosphere where runners are encouraged to wear costumes, with prizes awarded for best individual, group, and pet costumes.

The event supports local trails through the nonprofit Endless Trails and limits participation to 50 runners for an intimate, old-school experience. Visit the organization's website for the most recent information.