DateExpected
Early October 2027
Based on past editions. We'll confirm when the organiser announces.
Venue
High Hope Ranch, Glen Rose, Texas
Glen Rose, Somervell County
Countdown
October
The big one: a 99 km day built from repeated laps of the same trails, so you know exactly what is coming every time round. A small field of 22 in just its second year.
Key facts
01Cut-off is 24 or 26 hours, sources differ, so check before race day
02Six laps of the Silver loop plus the Spur loop
Create a free training plan for the The Mammoth Trail Run 99 km
7-day free trial, no card required
The course
One lap, on repeat
Glen Rose · one lap
Distance99km
Start · finishOne lap · elevation
0 kmDrag map to rotate10.6 km
Weather
Early-October, Glen Rose
30°CTypical high
16°CTypical low
4°CColdest in 20 years
23%Days with rain
Highs around 30°C and lows around 16°C, but it has dropped to 4°C. Rain on 23% of days.
NASA POWER data, 2006-2025, the week either side of race day
Results
Course verified. Results not yet available.
Organiser
Training
Training for the The Mammoth Trail Run 99 km
We don't do generic plans. We combine deep knowledge of this race's demands with your recent training, then build a plan with you that progresses as you do.
Beina integrates directly with your existing tools to understand your current fitness, and synchronise your planned sessions.
Intervals.icuWhat a The Mammoth Trail Run 99 km plan targets
Typical sessions
99 km
Time on feet and fatigue resistance
Fuelling and pacing for the whole event
What your weeks look like
Typical sessions
Long runs that build time on your feet
Tempo and threshold sessions to hold race pace
Back-to-back weekend runs for fatigue resistance
Not a generic schedule
Typical sessions
Built from your current fitness and the time you actually have
Adapts every week as Beina learns how you respond
Syncs your sessions straight to Garmin and Wahoo
One clear next session, never a wall of spreadsheet
Entries open now
Get your The Mammoth Trail Run 99 km plan.
7-day free trial, no card required.
Other races at The Mammoth Trail Run
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