Cottontail 6 & 12 Hour
Seattle, United States • 18 Apr 2026
Event overview
The Cottontail 6 and 12 Hour is an in-person timed running event held in Carkeek Park, Seattle, WA on April 18, 2026. Participants may choose to run for six hours or for twelve hours. A separate virtual option for 2026 is available through a different registration page. Registration closes on Wed, Apr 15 at 11:59 PM PT.
Course and format
The event is run on a clockwise loop course. The main loop is 1.93 miles with an additional 0.54-mile loop available most of the day. Each main loop contains 436' of vertical gain. The course includes steep stairs, rolling trails, singletrack sections, viewpoints of the Sound, forested areas with ferns and spring flowers, and varied uphill and downhill sections. Organizers use hand-made bibs and count laps with star stickers.
Entry, fees, and fundraising
Base entry prices listed are $50 for the 6-Hour and $60 for the 12-Hour for the in-person event. Virtual entries are listed starting at $35. Prices include US sales tax and UltraSignup fees. Registrations are non-refundable and non-transferable. The event is a fundraiser for Endless Trails, a 501(c)(3) nonprofit; proceeds beyond race costs support trail work, education, and advocacy. Organizers accept on-site cash and check donations. Visit the organization's website for the most recent information.