Tunnel Hill 100 & 50 Mile Runs

Event overview

Tunnel Hill 100 takes place Saturday, November 8, 2025 in Vienna, Illinois, with the start and finish at Vienna City Park (302 E. Vine St). The event includes multiple distances and is limited in field size for some races. Registration closes on Thursday, November 6. The event is USATF sanctioned and holds IAU Golden Label status for the 100 mile and 50 mile distances. It is a UTMB index race and a qualifier for Western States.

Distances and course

• 100 miles
• 100 km
• 50 miles (host of the 2025 USATF 50 Mile Road Championships)
• Marathon

The course uses the Tunnel Hill State Trail in an out-and-back format. The 50 mile course begins at Vienna City Park, runs south to the Wetlands Center at 13.1094 miles, then north 25 miles to a northern turnaround and back to Vienna to complete 50 miles. The 100 mile distance is two laps of that 50 mile course. The 100 km continues past the first southern aid station to a certified turnaround to complete the 100 km distance. The 50 km and 100 mile routes pass through the trail tunnel multiple times.

Rules, time limits and aid

Time limits for the 50 mile, 100 km and 100 mile races are 30 hours. 100 mile runners must begin the second 50 in under 15 hours to remain eligible for a 100 mile finish. Championship eligibility for the USATF 50 Mile awards requires USATF membership and U.S. citizenship. Shoe rules follow IAU guidelines - commercially available shoes with sole thickness not greater than 40 mm and no more than one carbon plate are allowed. Pacers are permitted with registration and a fee, but pacers are not allowed for official record attempts; an additional bib must be worn on the back for championship competitors. Aid stations will provide water, a hydration drink, food items and limited cups; porta johns are available at several aid stations. Drop bags are handled at designated locations with a recommended size. Visit the organization's website for the most recent information.