Welcome to Rim Rock 50m Trail Challenge
Welcome to the 2nd aunnual Rimrock 50 Mile Trail Challenge
Saturday, May 15, 2027 — Skyline Wilderness Park | Napa Valley, CA
The Rimrock 50 Mile Trail Challenge, a bold new ultra designed to test your limits and reward you with some of the most stunning and rugged terrain in Northern California. This isn’t just another race—it’s an experience built for those who want more. More challenge. More grit. More connection to the trail.
Your journey begins at Skyline Wilderness Park and pushes deep into the wild—through the rolling terrain of Napa Open Space and into the newly opened Suscol Headwaters Trail System. These are trails few have run, offering untouched beauty, relentless climbs, oak-covered ridgelines, and sweeping views across Napa Valley and beyond.
This course will challenge you. It will test your patience, your strength, and your mindset. And somewhere out there—on a climb, in a quiet stretch of trail, or pushing through the final miles—you’ll find exactly what you came for.
Whether you’re racing for a podium, chasing a personal breakthrough, or simply here to be part of something new, you are part of the foundation of this race.
This year we have added a 1 loop challenge 25ish miles. Let’s make it unforgettable.
See you on the trails,
—Rimrock 50 Mile Race Directors
Trail Squirrel Adventures Team
Race Information and Registration
Race Start
RACE START: 5:30 AM SHARP for both distances.
This is the NEW start time — be ready.
Mandatory race briefing: 5:25 AM.
We start on time. Don’t miss it.
Extras
Add crew/pacer meals and extra hats during registration.
Race Morning
- Gates open at 4:45 AM.
- Arrive ready. Volunteers will direct parking.
- Pick up your bib at the registration/swag tent.
- Shirts will be handed out when you finish.
- Be dialed in and at the start line on time.
- Finisher swag is earned at the finish.
SHOW UP READY. RUN HARD. EARN IT.
Directions and Parking
Event Location:
Skyline Wilderness Park
2201 Imola Avenue
Napa, CA 94559
Gate Access & Arrival Time
The Event Gate opens at 4:45 AM. This gate is located approximately 1/8 mile before the main park entrance. Look for red cones and our volunteer staff at the gate. Runners and crew arriving at this time will be directed to the overflow parking field.
Do not enter through the main gate. The main gate does not open until 7:00 AM and requires a $6 entrance fee. If you enter through the main gate, you will need to park in the upper lot and walk down to the start/finish area.
Please do not arrive before 4:45 AM. Campers and horses will still be sleeping, the gates will be closed, and there is 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 5:30 AM race start.
Drop Bags
There will be a designated drop bag area 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. Roughly half of the course is shaded by oak trees, and the other half is exposed, so plan accordingly.
Directions and Parking
Event Location:
Skyline Wilderness Park
2201 Imola Avenue, Napa, CA 94559
Gate Access & Arrival Time:
The Event Gate opens at 4:45: 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 4:45am there are campers and horses still sleeping . 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 5:30 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 description
The Rim Rock course features 2 1/2 rugged loops through Skyline Wilderness Park, the Napa Open Space Preserve, and the new Soscol Headwaters Trail system. Each large loop is approximately 22 miles and the last loop you run the 10k so you get a break on elevation. Solo runners will complete both loops (about 51 miles total).
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:
You need to average a pace of 16.5min miles to complete the course in 14 hour final cut off. There will be 2 major cut offs one before your second loop (under 6) hours and one before you start your final 6 mile loop. ( 12 hours 5:30pm )View the Strava Route
Updated Course Map
View the Strava Route
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, only after the fist loop starting from the Start/Finish area.
• Pacers are not permitted for relay teams., Pacers must carry their own nutrition Bay Trailrunners will supply water and hydration
Aid Stations and Course Markings
Ribbon colors will be discussed at the Mandatory pre race meeting at 5:20 am
Race Day Check In and Race Breifing
Registration dest for bib pick up opens at 5:am or if your coming with us you can stop by the Bay Trail Runners camp site from 7-8 pm Friday night
Runner Swag
Every registered Runner will receive a dry wick collard-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 race credit / gift card . Age group awards will be handed out if there are over 150 participants total. Light weight cold/hot tumbler will be offered
Vendors and Sponsors
On-Course Support & Vendors
Hydration and gels will be available on course to keep you fueled and moving. We’ll be serving Skratch and Cure Hydration, along with GU gels. All three major aid stations will be stocked with fruit and classic ultra fare—including PB&J sandwiches, cookies, chips, and more.
Yousef’s Gourmet Foods will be serving hot and cold wraps and snacks post-race, with vegan options available—perfect for recovery and refueling.
Victory Sportdesign will be onsite with drop bags and merchandise, so you can check out gear and pick up any last-minute essentials.
Helpful Links
Skyline Wilderness Park – Camping & Park Information
Victory Sportdesign – Order Here
Cure Hydration
Long Run Coffee
GU Energy
Stretch Hydration
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
Race photos will be provided by Jay Boncodin. Photos will be available to view at no charge, with the option to purchase high-resolution images directly from the photographer.
We’re also working on a new platform to store and share your race memories—details and access will be emailed out after the event.
If you or your crew take photos during the race, we’d love to include them!
📧 Please send any photos to info@baytrailrunners.net so they can be shared with the community.
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
Refunds & Transfers
Entry fees for Bay Trailrunners (Trail Squirrel Adventures) events are non-refundable and non-transferable, and we do not offer deferrals to future races.
All aspects of the event—permits, insurance, swag, awards, and logistics—are planned and paid for well in advance of race day.
👉 No bib transfers are allowed.
If a runner is found competing under another person’s registration, their bib will be pulled, and they will not receive an official result or race swag.
Race Cancellation Credits
If you are unable to attend, you may qualify for a race credit by notifying us in writing:
75% credit – Notify us 30 days prior to the event
50% credit – Notify us 14 days prior
25% credit – Notify us at least 72 hours prior
📧 Email: info@baytrailrunners.net
Credits are valid for 1 year from the issue date
Registration platform fees are non-refundable and not credited
No-shows receive no credit
Event Changes & Cancellations
Races will not be canceled due to rain or heat
Course changes (reroutes, trail work, closures) may occur at any time due to permitting agencies—these are outside of race management control, and no refunds or credits will be issued for such changes
If a race location must change due to park closures, registrations will be automatically transferred to the new venue
Participants may choose to cancel, but entries remain non-refundable and non-transferable
In the event of cancellation due to extreme weather, fire, or unsafe air quality, the race will be:
Rescheduled, or
Issued a 50% credit toward a future event
Any cancellation decision will be made with the safety of runners, volunteers, and staff as the top priority.
Event Swag
While we make every effort to provide all advertised swag, we reserve the right to substitute items due to supply chain or vendor issues.
👉 Swag will not be mailed if it is not picked up on race day.
Thanks for understanding and supporting a grassroots trail running community.
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
Poles and Music
running poles are permitted during the event. We just ask that you do not use them at the start finish as it could be a little crowded when you were out on the trail is the best time to bring them out. Please do not drop them at an aid station. We will not be responsible for getting them back to you. You may use headphones, AirPods or music in an ear device on the trails. Please remember some of them are single track and we ask on those that you only have it in one ear. Please do not use a speaker as a disturbs other Park guest and other runners.
Event's current local time: 7:05 AM PT
