Welcome to Rim Rock 50m Trail Challenge
Welcome to the Inaugural Rimrock 50 Mile Trail Challenge!
Saturday, May 16, 2026 – Skyline Wilderness Park, Napa Valley, CA
We’re thrilled to welcome you to the very first Rimrock 50 Mile Trail Challenge—a bold new endurance event that showcases the breathtaking beauty and rugged terrain of Napa’s finest trail systems. This isn’t just another race—it’s a journey through history, wilderness, and the raw edge of adventure.
Your challenge begins in the heart of Skyline Wilderness Park, winds through the scenic Napa Open Space Preserve, and ventures deep into the newly opened Suscol Headwaters Trail System—a pristine and rarely accessed stretch of wild hills, oak forests, and sweeping valley views.
Whether you’re here to race, push your personal limits, or just soak in the spirit of the trail running community, you’re part of something special. Thank you for being part of year one. Let’s make it epic.
See you on the trails,
—The Rimrock 50 Mile Race Directors and the Trail Squirrel Adventures Team
Race Information and Registration
Race Start: 6:00 AM sharp
Be ready to run on time—there will be a mandatory 5-minute race briefing at 5:45 AM.
Registration & Pricing:
Register now on UltraSignup to lock in the best possible price. There are two upcoming price increases, so the earlier you sign up, the more you save!
Extras at Registration:
When registering, you’ll have the option to purchase additional meals for your crew or pacers and extra hats.
Race Morning Details:
- Skyline Wilderness Park gates open at 5:30 AM. No need to arrive too early.
- Head to the registration tent to pick up your bib and race shirt.
- Finisher swag will be handed out at the finish line—something to look forward to!
Directions and Parking
Event Location:
Skyline Wilderness Park
2201 Imola Avenue, Napa, CA 94559
Gate Access & Arrival Time:
The Event Gate opens at 5:30 AM. This is 1/8 mile before the main entrance to the park. Look for red cones and our volunteer staff at the gate. Runners and crew arriving at this time will be directed to our overflow parking field.
Do not enter through the main gate—it does not open until 7:00 AM and will require a $6 entrance fee. If you do enter through the main gate, you’ll need to park in the upper lot and walk down to the start/finish area.
Please do not arrive before 5:30 AM. The gates will be closed and there’s limited space for cars to line up on the road. You will have plenty of time to check in and get to the start before the 6:00 AM race time.
Drop Bags:
There will be a designated area for drop bags near the start/finish line—look for the blue tarp. Be prepared for changing weather conditions: mornings can be foggy and cool, while the afternoon may get very hot. Half of the course is shaded by oak trees, and the other half is exposed, so plan accordingly.
Camping at Skyline Wilderness Park
Skyline Wilderness Park – Napa, CA
Skyline Wilderness Park, nestled in the scenic foothills of Napa Valley, offers a rich blend of natural beauty, community history, and outdoor recreation. Spanning over 850 acres, it’s the perfect backdrop for trail adventures like the Rimrock 50-Mile Trail Challenge.
A Glimpse into the Past
Once part of the Napa State Hospital grounds, the land was declared surplus in 1979. Through community advocacy, Skyline Wilderness Park was officially opened to the public in 1983, preserving its native landscapes for future generations.
Amenities and Activities
- Camping: Tent and RV sites available with hookups. Details here.
- Trails: 25+ miles of trails for hiking, biking, and horseback riding.
- Disc Golf & Archery: 18-hole disc golf course and full archery range.
- Martha Walker Native Habitat Garden: A peaceful, educational garden to explore local flora.
- Equestrian Camping: Dedicated areas for horse campers with facilities.
Rimrock 50-Mile Trail Challenge
The Rimrock Challenge takes full advantage of Skyline’s rugged trails, offering stunning views, tough climbs, and serene woodlands. Runners experience a full range of terrain from shaded oak forests to exposed ridgelines.
Camping: May 15–17, 2026
Whether you're racing or cheering, camp with us at Skyline Park on May 15, 16, and 17, 2026. Stay close to the action and enjoy the weekend in the heart of wine country.
Click here to reserve your campsite
Campsites are assigned first-come, first-served upon arrival. Check-in after 1:00 PM. Check-out by 11:00 AM.
Course Map and Elevation Profile
Rim Rock 50M Trail Challenge 2026 The Rim Rock course features two rugged loops through Skyline Wilderness Park, the Napa Open Space Preserve, and the new Soscol Headwaters Trail system. Each loop is approximately 26 miles. Solo runners will complete both loops (about 52 miles total), while relay teams of two will each complete one loop.
Please note that this route is an estimate and may be modified closer to race day due to natural terrain, trail conditions, and access permissions.
Course Preview: View the full route on Strava
Completion Times and Cut Offs
there is a 13 hour total course cut off we are still waiting for Aid station placement in the New NAPA open space section so pace chart and mild distance in between aid station will be added closer to the event so Runner will have 13 full hours and if there is a relay team of two each Runner will have 6 1/2 hours to finish their section.
Crew and Pacer Information for Rimrock 50-Mile
Crew Access:
• Crew will be allowed at the Start/Finish area and at the Lake Marie Aid Station, which is approximately a 2-mile walk from the Start/Finish.
• Crews may bring a drop bag to the Lake Marie Aid Station and assist their runner with anything needed at that location.
• Crew is not allowed at the Napa Road Aid Station or the new Soscol Headwaters Aid Station under any circumstances.
Pacer Policy:
• Pacers are only allowed for solo 50-mile runners, and only for the final 25-mile loop starting from the Start/Finish area.
• Pacers are not permitted for relay teams.
Aid Stations and Course Markings
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Race Day Check In and Race Breifing
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Runner Swag
every registered Runner will receive a dry wick T-shirt with Race icon. Every finisher solo or relay will receive a Rimrock Trail challenge truckers hat with icon. Top male and female runner will receive a Victory Sportdesign great bag. Age group awards will be handed out if there are over 150 participants total. Coffee mug or pint glass or wine glass will be offered
Vendors and Sponsors
As we get closer to the event more sponsors and or vendors will be added
Yousef’s Gourmet foods
Long Run Coffee
Pickle Juice
Beer City
Victory Sportdesign
Pre/Post Race Day Food-Drink
We want to make sure you’re well-fed and taken care of out there!
Our 4 aid stations will be stocked with classic ultra running fuel—think salty snacks, sweet treats, fresh fruit, hydration options, and more to keep you moving strong.
After you cross the finish line, we’ll have a hearty post-race meal waiting for you—featuring burrito wraps, fresh salads, fruit, sparkling water, juices, and a mix of sweet and savory snacks. Adult beverages will also be available for those who’d like to celebrate!
Hot coffee will be available before the race starts for runners and their pacers. Friends, family, and crew can purchase extra coffee either during the registration process or on-site.
Cup Free Race Information
Trail Squirrel Adventures is proud to be a cupless event, reflecting our commitment to environmental stewardship and sustainable trail running. By requiring all participants to bring their own reusable cups or hydration systems, we aim to significantly reduce waste and preserve the natural beauty of our trails. 
Why Go Cupless?
1. Environmental Conservation
Traditional races often generate substantial waste from single-use paper or plastic cups at aid stations. For example, a race with 500 participants can use over 10,000 disposable cups in a single event. By eliminating these, we prevent litter on trails and reduce the environmental impact of our races.  
2. Trail Preservation
Our races take place in pristine natural environments, and it’s our responsibility to keep them that way. Cupless racing ensures that we leave no trace, maintaining the integrity of the trails for future runners and local wildlife. 
3. Promoting Sustainability in the Running Community
The shift towards cupless races is part of a broader movement in the ultrarunning community to adopt more sustainable practices. By participating in cupless events, runners contribute to a culture that values and protects the environment.
What You Need to Know
• Bring Your Own Hydration Solution: All runners must carry their own reusable cup, bottle, or hydration pack. Collapsible silicone cups are a popular choice due to their lightweight and compact design.
• Aid Station Support: Our aid stations will be equipped to refill your personal hydration containers with water and electrolyte drinks. Volunteers will assist in ensuring a quick and efficient process.
• Available for Purchase: If you don’t have a reusable cup, we offer affordable, eco-friendly options for purchase during registration or on race day.
Join Us in Making a Difference
By embracing the cupless initiative, you’re not only participating in a race but also taking a stand for environmental responsibility. Together, we can make a positive impact on our planet and set a standard for sustainable practices in the running community.  
Thank you for supporting our efforts to keep the trails clean and our races green.
Race Photos
as always we have some great photographers that join us their names will be listed along with a link to their photos as soon as they are confirmed in early 2026
Cheer and Picinic Race Day
TBA
Volunteering
Why Volunteers Matter
Trail races like ours simply wouldn’t be possible without the help of volunteers. Their time, effort, and energy are what keep things running smoothly—from marking the course and staffing aid stations to cheering runners on and helping with clean-up. This support allows us to keep entry fees low and ensure the race experience stays high-quality and community-driven.
Volunteering is also one of the best ways to give back to the trail running community. Whether you’re a runner yourself or just someone who loves the outdoors, your involvement makes a real impact.
We appreciate every single person who steps up to help. If you’d like to join us, head to the Volunteer tab at the top of the page and click the Volunteer button under the cover photo to sign up.
Please help us spread the word—bring a friend, a family member, or a trail buddy. The more, the merrier.
All volunteers will receive a race shirt and lunch/meal
Thank you for being part of the trail family!
Refunds, Transfers, Race Credit Policies
Below is our standard policy for Trail Squirrel Adventures LLC.
Refunds & Transfers
Entry fees associated with Trail Squirrel Adventures events are non-refundable and non-transferable, nor do we offer deferrals to future races. Contracts, permit fees, awards, shirts, and all things associated with your event are planned and paid for long before your race day. We also do not transfer entries from runner to runner for various reasons. If a runner is found to be running under someone else's registered name, the bib will be pulled and the runner will not get credit for the race, or race swag.
Race Cancellation Credits
For 75% race credit towards another Trail Squirrel Adventures event, you must notify us in writing 30 days before your event at todd@trailsquirreladventures.com. For 50% race credit, you must notify Trail Squirrel Adventures 14 days before your event. For 25% race credit, you must notify Trail Squirrel Adventures prior to 72 hours remaining before your event. Your race credits will be valid for one year from the time you earned them. Fees from registration sites are not refunded or credited. Not showing up to the event will result in no credits.
Once again, registered runners can participate, and you may not exchange your entry with another individual.
Races will not be canceled due to rain or heat. Course trail work, closures, reroutes or construction may lead permitting agencies to require changes to the printed courses at any time prior to an event. This is out of the control of any race director, and we therefore will not offer refunds or credits in such a situation. If a race location is changed due to park closures, we will automatically transfer the registration over to the new venue; or entrants may choose to cancel their entry (non-refundable and non-transferable). Races cancelled due to inclement weather, fire or unsafe AQI will be rescheduled, or credited 50% towards a future race. Cancellation will only happen in the best interest and safety of the runners, staff and volunteers.
Event Swag
While every effort is made to insure that advertised swag is provided, we do reserve the right to change swag due to shipping and vendor fulfillment and supply chain inconsistencies. We do not mail swag not picked up or left behind.
Race Day Registration
if the race is not at capacity Race a registration will be available for premium charge so save now and register before race day. If you plan to register on race day please show up at a minimum 45 minutes before the start of your race to complete your waiver and pick up your bib. There is a race briefing 15 minutes before the start of every distance it is highly recommended that you attend and download your Strava GPS map from the registration page
Skyline Wilderness Park
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Suscol Headwaters Park
Suscol Headwaters Park: Napa's Newest Trail Destination Suscol Headwaters Park is a 709-acre open space preserve just south of Napa. Managed by the Napa County Regional Park and Open Space District, it connects directly to Skyline Wilderness Park via the Napa Solano Ridge Trail.
Opened in 2020, the park protects diverse wildlife habitats including grasslands, oak woodlands, and creekside corridors. Over 130 native species live here—bobcats, foxes, coyotes, and even the threatened steelhead trout.
Runners will experience winding trails with panoramic views stretching from Mount St. Helena to San Francisco Bay. This natural gem offers a rare, unspoiled look at Napa's backcountry.
There’s no fee to access Suscol, but Skyline Park’s event entrance is $6 per vehicle. No restrooms or water stations exist in the Headwaters area—please come prepared.
Volunteer-built trails like Perdida Trail have been developed with support from Redwood Trails Alliance and local community groups.
By running here, you’re supporting conservation and responsible recreation in one of Napa’s most important open spaces.
Bay Area Ridge Trail
The Bay Area Ridge Trail The Bay Area Ridge Trail is a bold, ongoing project to create a 550-mile multi-use trail around the entire San Francisco Bay. Over 400 miles have already been completed, connecting more than 75 parks and open spaces across nine counties.
Designed for hikers, runners, mountain bikers, and equestrians, the Ridge Trail highlights the beauty of the Bay Area’s ridgelines—offering panoramic views, redwood forests, oak woodlands, and wild open hills.
This project plays a critical role in conservation, recreation, and community health. It links parks and preserves, fosters partnerships among public agencies and nonprofits, and promotes active outdoor lifestyles.
The Rim Rock 50M Trail Challenge will utilize segments of the Ridge Trail as it winds through Skyline Wilderness Park and into the greater Napa Open Space network. When you run with us, you're helping support this vital regional resource.
Learn more and get involved at:
ridgetrail.org
Event's current local time: 10:29 PM PT
