
The Mammoth 2026 - 100K / 50K / 25K / 10K / 5K and Mighty Mammoth 1K Fun Run
Sat, Oct 10, 2026, 7:00 AM CDT
- Location
- Glen Rose, TX
- High Hope Ranch and Retreat Center, 76043
- Type
- TRAIL
Sign up and verify details on the organizer’s official page.
At a glance
Explore the scenic trails of a vast Texas ranch, offering distances for all, from a 1K fun run to a challenging 100K ultra.
- Fun
- Scenic
- Competitive
Great for: casual, fun-first runners, runners who like a competitive edge
The Mammoth Race invites you to a multi-distance trail running event set amidst the stunning Hill Country of Glen Rose, TX. Held on a thousand-acre ranch, this event welcomes runners of all skill levels across distances from 5K to 100K, including a 1K fun run. Experience pristine natural landscapes, well-marked trails, and 'round-the-clock aid stations, culminating in a lively post-race celebration with music, food, and refreshments.
What to expect
- Run through the beautiful Hill Country on well-marked trails across a sprawling thousand-acre ranch.
- Benefit from 'round-the-clock aid stations approximately 3.5 miles apart.
- Enjoy a post-race celebration with music, food, and refreshments.
Standout details
- Finisher buckles for 100K ultra participants
- Scenic routes through pristine natural landscapes
- Generous cut-off times for 100K
- Overnight tent camping and boondocking available
Perks & features
- After-Party
- Awards
- Chip Timed
- Food & Drink
- Shirt
From the public listing — confirm on the official site.
Auto-drafted from the public listing — confirm details on the official event page before signing up.
Distances & registration
7 optionsRegistration for all distances is through the official signup link above.
- 1K
Sat, Oct 10, 11:00 AM CDT · From $32.80
Opens Nov 5, 2025, 7:00 PM CST · Closes Sep 18, 2026, 7:59 PM CDT
- 5K
Sat, Oct 10, 9:00 AM CDT · From $59.30
Opens Nov 6, 2025, 6:59 PM CST · Closes Jul 21, 2026, 7:59 PM CDT
- 10K
Sat, Oct 10, 8:30 AM CDT · From $69.90
Opens Nov 6, 2025, 6:59 PM CST · Closes Jul 21, 2026, 7:59 PM CDT
+ 4 more optionsHide
- 25K
Sat, Oct 10, 7:30 AM CDT · From $91.10
Opens Nov 6, 2025, 6:59 PM CST · Closes Jul 21, 2026, 7:59 PM CDT
- 50K
Sat, Oct 10, 7:15 AM CDT · From $122.90
Opens Nov 6, 2025, 6:59 PM CST · Closes Jul 21, 2026, 7:59 PM CDT
- 100K
Sat, Oct 10, 7:00 AM CDT · From $165.30
Opens Nov 6, 2025, 6:59 PM CST · Closes Jul 21, 2026, 7:59 PM CDT
- 100K
Sat, Oct 10, 7:00 AM CDT · From $0.00
Opens Nov 6, 2025, 6:59 PM CST · Closes Oct 10, 2026, 7:59 PM CDT
Vibe Check
Push Potential
Trail course, longer distance
- Mostly trail
Partial data — terrain or weather signals missing.
The course
- Trail
- Timed race
From the organizer
Get ready for The Mammoth Race Glen Rose FALL migration. This multi-distance trail run welcomes families and runners of all skill levels. Enjoy the Hill Country that surrounds this stunning ONE THOUSAND acre ranch. We can't wait to see you out there!
The Mammoth - Glen Rose, TX is a multi-distance trail running event located on the trails High Hope Ranch and Eco-Retreat . Distances offered are 100K, 50K, 25K, 10K, 5K and The Mighty Mammoth 1K FUN RUN. There will be two sections of the course: a 3.5-mile loop and a 7-mile loop. Both loops combined equal a 10.5 mile lap. The event will run from 7 am on Saturday morning until 9 am on Sunday morning. The starting line and Main Race Hub will be the main lodge on the Ranch. There are two aid stations on course: the main lodge at the starting line, and Matazamo ranch house. Aid stations are approximately 3.5 miles apart. RACE CATEGORIES:
100K - 26hr Cut-off time 50K 25K 10K 5K Mighty Mammoth 1K Fun Run - NON-CHIP TIMED EVENT . RACE HIGHLIGHTS:
Finisher Shirts and Medals Generous Cut Off times - Cut off time for 100K only! Finisher BUCKLES for 100K Ultra Scenic routes through pristine natural landscapes Well-marked trails and 'round the clock aid stations Exclusive sites for tent camping and boondocking (no hook-ups) Post-race celebration. Music, food and refreshments! ADDITIONAL INFO:
PETS ARE NOT ALLOWED. USATF sanctioned event policy does not allow for animals to participate in competitions. The Mammoth is an Enviro-Friendly Event - B.Y.O.B (Bring Your Own Bottle) RAIN or SHINE. In the event of inclement weather that would threaten the safety of the racers, the event or courses may be altered or the event may be delayed or canceled.
RACE DAY SCHEDULE
100K - 07:00am 50K - 07:15am 25K - 07:30am 10K - 07:45am 5K - 08:00am 1K - 10:00am CLASSIC SWAG
All participants will receive a Mammoth Race OFFICIAL Race shirt and a Finisher's Medal. Finisher BUCKLES for 100K ULTRAS AWARDS
NO PLACE FINISHER AWARDS. BRAGGING RIGHTS ONLY PACKET PICK-UP
RACE DAY on site PARKING
Price INCLUDES Entrance and Parking OVERNIGHT CAMPING
$10 per PERSON. NOT included in registration. Max 6 people per site. PAYABLE AT THE GATE REFUNDS/TRANSFERS
Race Entry Fees are NON-REFUNDABLE, however TRANSFERS to another Person, Category or Mammoth Event are allowed. COURSE MAPS - Viewable HERE
Also in this area
Similar vibe nearby
Races nearby with a similar atmosphere.
Easier options nearby
Lower-difficulty races in the same state.