One of the oldest continuously held ultramarathons in the United States returns this weekend, with the 44th edition of the Ice Age Trail 50 going off Saturday morning in Whitewater, Wisconsin. Established in 1981, the event has hosted runners across nearly half a century of changes in American ultrarunning, and Saturday's start line will look much as it always has, set in the rolling deciduous forests of the Southern Kettle Moraine. Both distances on offer, the 50-mile and the 50K, are sold out for 2026, with the 50-mile leading off at 6 a.m. sharp and the 50K following at 8:15 a.m.
The course traces the Ice Age National Scenic Trail, the long-distance footpath that follows the southern terminal moraine left by the last continental glaciers more than 10,000 years ago. Runners weave between kettles, kames, erratics and esker ridges, with the route broken into three character-defining segments. A 9.5-mile Nordic Loop opens proceedings from the start-finish at the Nordic trailhead. From there, the 50-mile field heads out and back to Rice Lake for roughly 20.5 miles before a second out-and-back to the Emma Carlin aid station closes out about 20 more.
It is technical without being punishing. Tall pines and rocky ridges share space with open prairie remnants, and the grade rarely climbs hard enough to warrant a hike, though sustained rolling terrain has historically softened up legs late in the day. The Ice Age 50 has long served as a spring tune-up for runners building toward summer 100s, and several alumni have used Whitewater times to seed expectations for races such as Mohican, Kettle Moraine 100 and Western States. The 50K, meanwhile, attracts a healthy mix of first-time ultra-distance runners and seasoned racers using it as a sharpener.
The event's longevity is a story in itself. The race grew out of the Wisconsin trail running community and has been continuously stewarded by a corps of long-tenured volunteers who keep aid stations packed and trail markers tidy through what can be temperamental May weather. Recent editions have run the gamut from cool and damp to unseasonably warm, and Saturday's forecast is firmly in the runner-friendly bracket. Race-day registration is closed, but spectators are welcome at the Nordic trailhead and at accessible aid stations along the course.
Beyond the racing, Saturday's afternoon party in Whitewater has long been part of the draw. The post-race tradition of free beer, live music and a long table of local food has earned the Ice Age 50 a reputation as a particularly social finish line, with veterans frequently lingering well into the evening to swap stories with newcomers. Saturday's headline times will be logged before mid-afternoon, but the larger story of the weekend will be the continued health of an event whose roots predate most modern American ultras.