The Tunnel Hill 100 Mile Run weaves through the wooded stretches of southern Illinois, starting and ending in Vienna, where the natural world flexes its steady, demanding presence. Covering a full century of miles along the Tunnel Hill State Trail, this ultra-run tests stamina and spirit against mostly flat but unyielding terrain. The course threads through hardwood forests and open farmland, with occasional views spooling out across the valley, giving runners brief moments to exhale and take in their surroundings before the next leg pulls them forward.

The trail’s surface alternates between packed crushed limestone and patches softened by fallen leaves and pine needles, which invite careful footing. Elevation changes are subtle but consistent—expect a cumulative climb around 3,500 feet, enough to remind you this run demands respect but not towering mountain training. The largest challenge is endurance: 100 miles across Illinois’ quiet countryside, where the natural elements take on their own character; the wind often pushes against you like a cautious gatekeeper, and the shifting shadows under the canopy mark the race’s slow but steady passing of time.

Preparation hinges on the basics: trail shoes with good grip to handle limestone dust and occasional mud, a hydration system that can carry multiple liters, and layered clothing given Illinois’ unpredictable spring and fall weather. Access points along the trail enable supply drops and aid stations but knowing when to refuel and when to conserve energy makes the difference between completion and cutoff.

The race attracts a tough yet welcoming set of adventurers, some drawn by the chance to test limits in a less crowded, more rustic environment than coastal ultras. Newcomers will appreciate the manageable footing and gentle grades, while seasoned racers will find the length itself a worthy foe. Even casual hikers can appreciate sections of the Tunnel Hill Trail, which invites a slower pace and rewards with glimpses of deer darting through underbrush or the bold song of warblers flitting overhead.

Timing the run for early spring or late fall avoids the region’s humid summers and gives runners a chance to encounter Illinois’ changing seasons in motion. Morning mists rise off the Big Muddy River, daring those who approach to keep pushing forward while the trail hums beneath every step. At the finish in Vienna, relief and accomplishment linger in the air, as tangible as the cool breeze pushing westward through tall oaks and maples. The Tunnel Hill 100 is more than a run; it’s a continuous conversation with a landscape fiercely itself, inviting endurance, respect, and a measured embrace of nature’s quiet power.