The Mammoth Trail Run 2026 - 100K / 50K / 25K / 10K / 5K and Mighty Mammoth 1K Kids Dash 2026
- Date
- Saturday, October 10, 2026
- Start time
- 7:00 AM start (Chicago)
- Location
- Glen Rose, Texas
- Entry fee
- From Free
- Included with entry
- Includes a shirt
Registration is open.
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Official race websiteAdd to calendar: Apple or Outlook · Google
Events and entry fees
| Event | Distance | When | Entry fee | Cap |
|---|---|---|---|---|
| 100K Ultra Trail Run | 100K | Oct 10, 20267:00 AM | $185 | – |
| PACER - 100K Ultra Trail Run | 100K | Oct 10, 20267:00 AM | Free | – |
| 50K Trail Tun | 50K | Oct 10, 20267:30 AM | $145 | – |
| 25K Trail Run | Other | Oct 10, 20268:30 AM | $105 | – |
| 10K Trail Run | 10K | Oct 10, 20269:30 AM | $75 | – |
| 5K Trail Run | 5K | Oct 10, 202610:00 AM | $65 | – |
| The Mighty Mammoth 1K Fun Run | Kids | Oct 10, 202611:00 AM | $35 | – |
Entry fees exclude processing fees. Prices and dates come from the race's registration page and refresh nightly.
Race day planning
Entry fee schedule
- 100K Ultra Trail Run: $185 until Oct 10.
- PACER - 100K Ultra Trail Run: Free until Oct 11.
- 50K Trail Tun: $145 until Oct 9.
- 25K Trail Run: $105 until Oct 10.
Online registration closes Oct 11, 2026, unless the race fills first.
How the price compares
At $185, entry is about the same as a typical 100K in Texas ($175).
Light and altitude
Sunrise on race morning is at about 7:29 AM, and the 100K Ultra Trail Run starts at 7:00 AM. The start sits about 770 feet above sea level.
Fees exclude processing fees. Comparisons use current entry fees and published results from races nearby.
Start location and course
High Hope Ranch, Glen Rose, TX 76043
The pin marks the address the race lists, which is usually the start. The organizers have not shared a course map with us yet.
Typical race-day weather
Around October 10 the day usually runs from 64°F at dawn to 86°F in the afternoon, with measurable rain on about 9% of days. Cold snaps dip to 54°F and hot years reach 93°F.
Based on 75 days within a week of the date over the last 5 years, from historical weather for the start area. Not a forecast.
Race details
- Where
- High Hope Ranch, Glen Rose, TX 76043Map
- Course
- Trail
- Start elevation
- About 770 feet
- Included with entry
- T-Shirt
- Distances
- 5K, 10K, 50K, 100K, Kids, Other
- Editions
- 2026 (Oct 10, 2026), 2025 (Oct 11, 2025)
Organize this race? Add details or a correction
Plan your race
Quick answers
- When is The Mammoth Trail Run 2026 - 100K / 50K / 25K / 10K / 5K and Mighty Mammoth 1K Kids Dash?
- Saturday, October 10, 2026, starting at 7:00 AM.
- How much does it cost?
- Entry starts at Free before processing fees.
- When does registration close?
- Online registration closes Oct 11, 2026, unless the race fills first.
- Is the entry fee high for Texas?
- At $185, entry is about the same as a typical 100K in Texas ($175).
- Do runners get a shirt or medal?
- Entry includes a shirt, according to the race's registration page. Check it for sizes and whether kids' races get the same.
- What distances can I run?
- 5K, 10K, 50K, 100K, Kids, Other.
- Where does it start?
- High Hope Ranch, Glen Rose, TX 76043.
From the organizers
THE MAMMOTH TRAIL RUN 🦣🏜️ A Chronicle of Grit and Wonder!
October 10, 2026 | High Hope Ranch | 3353 County Road 2009 I Glen Rose, Texas 📍
Attention all trailblazers, pioneers, and audacious gentlefolk! 🤠 The Mammoth Trail Run is calling you out to the untamed expanse of High Hope Ranch. We’ve carved out a thousand acres of rugged Texas Hill Country for a true test of your mettle. Gather the herd and prepare for an expedition that’ll leave you with legendary tales to tell. 🌵
A word to the wise: Some areas of the course feature downright STEEP inclines and declines. Trail shoes with heavy traction are highly advised to keep your boots firmly on the trail! 🥾