Thumb Coast Ultra & Relay - 50 Mile, 50K, & 50 Mile Relay

Thumb Coast Ultra & Relay – April 24, 2027

Thumb Coast Ultra & Relay is a one-of-a-kind spring ultramarathon in Michigan’s Thumb. On Saturday, April 24, 2027, runners and ruckers will take on the challenge of racing from Lake Huron in Harbor Beach to Saginaw Bay in Caseville in the 50 Mile division—or team up with friends for the 50 Mile Relay. The 50K features a flat out-and-back course starting and finishing in Caseville.

This race offers the rare opportunity to run point-to-point across the Thumb on mostly dirt and unimproved rural roads. With just 500 feet of elevation gain in the 50 Mile and 300 feet in the 50K, it’s a course that is both approachable for first-time ultrarunners and fast enough for seasoned athletes looking to chase a personal best. Generous cutoff times allow all participants a chance to achieve their goal, while 50 Mile finishers who “beat the sun” with a daylight finish earn a unique prize in addition to their medal.

Thumb Coast Ultra & Relay is more than just a race—it’s a test of endurance, teamwork, and determination supported by a welcoming community. Participants can expect a well-marked course, fully stocked aid stations, and the camaraderie of runners, ruckers, and relay crews tackling the same adventure together.

Why Run Thumb Coast Ultra?

Unique point-to-point ultramarathon from Harbor Beach to Caseville in the 50 Mile and Relay.

Flat and fast courses: 500 feet of elevation gain (50 Mile) and 300 feet (50K).

Relay option: Gather your crew and tackle the 50 Mile as a team.

Ruck divisions available in both the 50 Mile and 50K.

Generous cutoff times to support beginners and seasoned veterans alike.

Special prize for 50 Milers who beat the sunset at the Caseville finish.

Well-marked course with excellent aid stations, staffed by an enthusiastic volunteer crew.

A true spring race experience in Michigan’s Thumb, just before the busy summer season begins.