Rim Rock 50 Mile Trail Challenge
Napa, United States • 16 May 2026
Event overview
Rim Rock 50 Mile Trail Challenge takes place Saturday, May 16, 2026, at Skyline Wilderness Park in Napa Valley, CA (2201 Imola Avenue). The event offers the following distances:
- 50 mile solo
- 50 mile relay (teams of two)
Registration closes Friday, May 15 at 8:00 PM PT. Race-day registration may be available if the event is not full; race-day entrants must arrive early to complete a waiver and pick up their bib.
Course, support and logistics
The course uses two rugged loops through Skyline Wilderness Park, the Napa Open Space Preserve, and the Suscol Headwaters Trail system. Each loop is approximately 26 miles; solo runners complete both loops and relay teams of two each complete one loop. Terrain includes shaded oak woodlands and exposed ridgelines. The event is cupless - all participants must carry their own reusable cup, bottle, or hydration pack; aid stations will refill personal containers.
There are four aid stations stocked with standard ultra running fuel and a designated drop-bag area near the start/finish. A total course cutoff of 13 hours applies; relay runners have 6.5 hours for their section. Crew access is allowed at the start/finish area and Lake Marie Aid Station; crew access is not permitted at Napa Road Aid Station or the Suscol Headwaters Aid Station. Pacers are permitted only for solo 50-mile runners on the final loop. Camping is available on May 15–17 with first-come, first-served campsite assignment. Visit the organization's website for the most recent information.