The Mammoth - Glen Rose

OCT
10-11
2026
The Mammoth is a trail running festival in Glen Rose, Texas, set on a scenic 1,000-acre ranch. Runners can choose from distances ranging from a 1K kids' fun run up to a 100K ultra. All participants get a shirt and medal, with 100K finishers earning a special buckle.
10-11 Oct 2026
100 kilometers

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

The Mammoth - Glen Rose

This event is a multi-distance trail run taking place at High Hope Ranch and Retreat Center in Glen Rose, Texas. The course is set within a 1,000-acre ranch in the Hill Country.

The event offers six distances:

  • 100K Ultra Trail Run
  • 50K Trail Run
  • 25K Trail Run
  • 10K Trail Run
  • 5K Trail Run
  • The Mighty Mammoth 1K Fun Run (open to ages 1-11 and is non-chip timed)

The 100K event has a 26-hour cutoff time. The course consists of two loops: a 3.5-mile loop and a 7-mile loop. Combined, they create a 10.5-mile lap. The starting line and main race hub is the main lodge on the ranch. There are two aid stations on the course: one at the main lodge and another at the Matazamo ranch house, spaced approximately 3.5 miles apart.

All participants receive an official race shirt and a finisher's medal. Finishers of the 100K distance also receive a buckle. The event is rain or shine, though it may be altered or canceled for safety. Pets are not allowed, as it is a USATF-sanctioned event. Participants are encouraged to bring their own water bottle, as it is an environmentally friendly event.

Parking is included in the registration fee. Overnight tent camping is available for an additional $10 per person, payable at the gate, with a maximum of six people per site. Packet pick-up occurs on race day at the venue. Visit the organization's website for the most recent information.

100 km
100k Ultra Trail Run