Event Details
This unbelievable 20K looped course is a hidden gem inside the Dundas Valley Conservation Area of Ancaster, Ontario.
With wildlife teeming through this old Carolinian Forest, and waterfalls cascading over rocks along the course, your legs may not even notice traversing the over 500m / 1500 feet of elevation per 20K loop. Expect to be challenged on this (mostly) double track trail as you are supported with 4 fully stocked Aid Stations along the way.
The Sulphur Springs Trail Race 100K and 100 Mile events are now Western States Endurance Run Qualifying Races. We are proud to be the newest in Canada and the First race in Ontario to serve as a WSER 100 Qualifier. More details are available below.
This is the longest running Ultra Race in Ontario, dating back to 1992. Our 2026 race promises to be another great one - get your bibs early, this race sells out!
🏅 Your Participation
Track your plan, gear, and results.