Beat the Sunset in Caseville, Michigan!
Michigan’s Thumb is full of quiet roads, big skies, and unexpected beauty—and the 2027 Thumb Coast Ultra & Relay is your chance to run from one side of Lake Huron to the other.
On Saturday, April 24, take on a point-to-point 50 Mile from Lake Huron in Harbor Beach to Saginaw Bay in Caseville, a fast and scenic 50K out-and-back, or rally your crew for the 50 Mile Relay and chase the sun across the Thumb. Can you beat sunset to the finish?
This route follows mostly flat dirt roads through open farmland and lakeshore views, with generous cutoff times and fully stocked aid stations. It’s an ideal challenge for beginners going long for the first time, seasoned vets chasing a PR, or teams ready to take on 50 miles together. Whether you’re running, rucking, or relaying—this is your spring adventure.
Additional awards for 50 Mile finishers who “beat the sun.”
Let’s go coast to coast—Thumb-style.
Choose Your Race Day
50 Mile Run & Ruck
Run from Harbor Beach to Caseville across Michigan’s Thumb. Quiet dirt and unimproved roads, frequent aid stations, and a generous cutoff make this an approachable first 50 Miler, while experienced ultrarunners can chase the course record—or the sun.
50K Run & Ruck
Take on 31 miles through Michigan’s Thumb in this out and back course from Caseville with the same well-supported race-day experience as the 50 Mile. A great choice for a first ultra, a spring goal race, or experienced runners and ruckers looking for a long day on quiet roads.
50 Mile Relay
Share the trip from Harbor Beach to Caseville with a team. Relay exchanges break the 50-mile point-to-point course into manageable sections while your team spends the day moving together across the Thumb.
Why Runners Choose the Thumb
“I was surprised by the positive vibes… liked the course… was perfect for my first ultra, aid stations were excellent, and course was very well marked!” — Anonymous, 2026 Participant
“Of all the ultras I have run, this was the most organized and thoughtful.” — Elizabeth E., 2024 Participant
“Loved this whole concept of racing the sun and running in a beautiful area. The Thumb is awesome.” — Wendy, 2024 Participant
“All the runners, staff and volunteers were friendly and eager to help. Beautiful scenery, ample time finish and a feeling of belonging regardless of ability.” — Randy W., 2024 Participant
What's Included in Your Registration
- Custom Thumb Coast Ultra participant jacket
- Finisher's medal
- Thumb Coast Ultra bumper sticker
- Reusable 8 oz silicone race cup
- Race photography
- Post race food and drinks. In addition to traditional post race snacks, Trivium will serve hot food off the grill for finishers.
- Aid stations well-stocked with water, Tailwind, gels, and real food
- Chip timing by Trivium Racing
2027 designs will be announced soon.
Check Out the Race Swag
Plan Your Race
Check out the Athlete Guide for details about the race day schedule, parking, course markings, aid stations, drop bags, cut-off times, and more!
Race Weekend Schedule Athlete Guide Aid Station Chart
Finisher's Medal
2027 design coming soon.
Participant Jacket
2027 design and style coming soon.
50 Mile & 50 Mile Relay Course
The 50 Mile course is point-to-point, starting at sunrise in Harbor Beach, Michigan and finishing on the beach at Caseville County Park. The course consists of ~85% dirt roads, 10% paved roads, and 5% unimproved park roads (think gnarlier and sandier than dirt roads). With ~500' elevation gain it's a gorgeous, fast course!
The course is open ~15 hours, give or take 10 minutes for sunrise/sunset.
Learn more and view the course on Strava:
50 Mile Course Details50K Course
The 50K course is an out-and-back course, starting and finishing on the beach at Caseville County Park. This course uses mostly unimproved and gravel roads. With ~220' of elevation gain it's a fun, fast race!
The course is open ~13 hours, give or take 10 minutes for sunrise/sunset.
Learn more and view the course on Strava:
50K Course Details
Official Training Plans
Official Thumb Coast Ultra & Relay training plans are $35 for Ultramarathon plans (20 weeks in length) and $25 for Relay plans (12 weeks in length). All plans are designed by our Ironroot Distance Coach Caleb & team. Learn more and purchase at the link below.
Training Plans
