
From the Organizer
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.
Events
Weather
It's too far out for a forecast, so here's what weather on this date is normally like in the area. A race day forecast will replace this as race week approaches.
Typical High
56°
Typical Low
35°
Based on US Climate Normals data from Filion 5nnw, 9 mi from the venue.
Host City
Population
675
as of 2023
Elevation
597 ft
Nearest Airport
MBS
MBS International Airport · 50 mi
Major Hub
DTW
Detroit Metropolitan Wayne County Airport · 120 mi
Time Zone
Eastern Time
From Endurance Grid
A small town race. Lodging near the start could be limited, so book early.
Race Location
Your Next Start Line
Every finish line starts with a single decision. Claim your spot at Thumb Coast Ultra & Relay - 50 Mile, 50K, & 50 Mile Relay, put it on the calendar, and turn “someday” into a start date.
320
Days to train
Coming Up
Ubly Homecoming 5K
23 miles away
Sunset Classic 5K
9 miles away
Port Austin Run and Walk
14 miles away
Laker 5k Run/Walk and 1/4 Mile Kids Fun Run
9 miles away
From Endurance Grid
Endurance Grid is here to help you understand the sport, decide if it's the right fit, and learn how to prepare. For course distances, logistics, and race-day specifics, always defer to the race organizer's event page.
With running, there's a distance for every fitness level, a community at every start line, and nothing beats the feeling of crossing a finish line you trained for.
Running is an endurance sport that rewards consistency, and showing up every week compounds in ways that will surprise you.
From 5K to marathon, running races are the most accessible entry point into endurance sport. There's a distance for every fitness level and a community at every start line.
Frequently Asked Questions (FAQs)
Thumb Coast Ultra & Relay - 50 Mile, 50K, & 50 Mile Relay
Apr 24, 2027