The Piasa

MAY

16

2026

The Piasa Trail Races challenge runners on the technical, hilly singletrack of Pere Marquette State Park. Choose from 12.5K, 25K, or a demanding 50K with significant elevation. Run solo or team up with a buddy in the unique partner division.

Sat 16 May 2026

St. Louis, Missouri

Registration

Always double-check with the organizer's website! This page may contain affiliate links.

Event Details

The Piasa is a trail running event taking place in Pere Marquette State Park near Grafton, Illinois. The races are inspired by the local legend of the Piasa, a mythical creature from Illiniwek folklore.

Courses & Terrain

The event features three race distances on trails within the park's rugged bluffs and forested ravines. The courses are known for technical footing, sustained climbing, and demanding descents.

12.5K
25K
50K - This longest distance includes approximately 4,000 feet of climbing.

Race Format

Participants can register in one of two divisions. The Solo Division is for individual runners. The Buddy Division is for two runners who must start and complete the entire race together.

Other Information

Packet pickup occurs at the Pere Marquette Visitors Center. The event offers custom, hand-crafted awards for top finishers. Lodging and camping are available at or near Pere Marquette State Park. The organizers' registration policy states that refunds are not offered, but medical deferrals to the following year's event may be possible with documentation. Visit the organization's website for the most recent information.

12.5k Run

25k Run

50k Run