The VOID

The Void

The Void is a 48 hour out-and-back ultramarathon held inside Sideling Hill Tunnel near Valley-Hi, Pennsylvania and organized by ESTEA. The course runs entirely within an abandoned tunnel that has no interior lighting.

Runners complete 63 out-and-backs through a 1.3-mile corridor, totaling just under 160 miles. The format places repeated, identical laps on pavement with frequent turnaround points so participants confront the same environment again and again.

The event emphasizes psychological and strategic elements as much as physical endurance. The tunnel is unlit and runners navigate using headlamps. Support access is managed by a physical Toll Ticket system issued at check-in; the ticket governs how often a participant may exit the tunnel to access outside support, making planning and discipline part of race strategy.

Entry requires an application reviewed by the race directors. Priority is given to applicants with demonstrated extreme endurance experience. Organizers recommend completion of at least one 100 mile ultramarathon, backyard ultra, FKT, or comparable extreme endurance event within three years of registration for stronger consideration. The field is limited to 96 participants.

The event is structured as an individual endurance challenge rather than a conventional race against other competitors, with emphasis on repetition, isolation, and individual decision making. Visit the organization's website for the most recent information.

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