Forbidden Run Fest 2026

Forbidden Run Fest is a fall trail-and-gravel race within Philadelphia's Wissahickon Valley Park, headquartered at Houston Recreational Center. Participants select from 10K, 10-mile, or half marathon distances, all crossing a blend of compacted dirt, wide gravel, single track, and rocky ascents. The event limits registration to 750 runners and employs chip timing, with aid stations positioned every 2 to 3 miles offering water, Gatorade, and snacks. It is designed for road runners new to trails and trail runners seeking a quicker course than a fully technical one. Much of the running occurs on Forbidden Drive, a 5.45-mile, 25-foot-wide gravel path with a mild maximum grade and significant daily use within the park. The half marathon incorporates approximately five miles of technical single track alongside eight miles of gravel, while the 10-miler features downhill single track and an out-and-back section on Forbidden Drive. All distances encounter a version of the race's challenging climb, Mount "What the heck," a rocky final quarter mile that adds difficulty near the finish. Following the race, participants receive fresh pizza, seasonal refreshments, live music, and comfortable race sweatshirts instead of typical disposable merchandise.