Caveman Challenge at Waterloo Lake

Caveman Challenge at Waterloo Lake is a trail event in Denison, Texas, on October 10, 2026, organized by Caveman Endurance. Five formats share the day around Waterloo Lake: a 50K (31.1 miles), a marathon (26.1 miles), a half marathon (13.1 miles), a 10K (6.2 miles) and a 5K (3.1 miles).

With five distances at one venue, this is the kind of race where a whole running group can sign up together and each pick their own goal. The 5K and 10K are welcoming to beginners and families, the half marathon is a natural target for road runners trying trails for the first time, and the marathon and 50K are well suited to a first ultra attempt, since North Texas lake trails tend to be runnable rather than mountainous. October in Texas can still be warm, so heat management matters as much as mileage: train in the warmer part of the day occasionally, carry fluids, and practice taking electrolytes. Give the ultra distances a 16-week build and the shorter races 8 to 12 weeks of consistent running.