Glen Rose, Texas · Saturday, November 21, 2026
The Dinosaur Valley Endurance Run is a 5 miles, 25k, 50k, 100k, 100 miles, and running event held on Saturday, November 21, 2026. It is located at 101 Southwest Barnard Street in Glen Rose, Texas.
We are working to fight senior isolation and food insecurity in Hood County! All proceeds raised from Step Up for Seniors will go to the Hood County Senior Center, where we provide daily meals, activities, and social events for our Senior community as well as our Meals on Wheels program, which is able to provide over 1000 meals weekly to our Hood County Seniors in need.
Race t-shirts guaranteed to racers registered by September 4, 2025.
Bring the family-fun for all ages and fitness levels!
Registration Fees (thru Sept 4) :
5K - $30.00
1M- $15.00
Registration Fees (after Sept 4) :
5K- $40.00
1M-$20.00
Award Categories: All participants will receive a participation medal!
Age Divisions: Male & Female
9 & under, 10-14, 15-19, 20-29, 30-39, 40-49. 50-59,60-69, 70 and over
5K: Medals awarded for top three Male and Female in each age group.
1M: Award ribbons to all participant finishers in each age group.
Early Packet Pick-Up: 10/01/25-10/03/25
Hood County Senior Center
501 E. Moore Street
Granbury, TX 76048
Morning of the race
Hood County Senior Center
Race Day Schedule:
Walk up registration: 7:30-8:15am
5K Run @ 8:30 a.m.
1M: 8:35 a.m.
Pets are welcome and MUST be on a leash!
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
PACKET PICK-UP
PARKING
OVERNIGHT CAMPING
REFUNDS/TRANSFERS
COURSE MAPS - Viewable HERE
The ICE AGE 5K is BACK in 2026 to kickoff the WINTER-GUEST TOURISM SEASON alongside VISIT GRANBURY in the Celebration Capital of Texas!
RUN, WALK or STROLL your way to the finish thru the heart of the BEST Historic Small Town in America
All Ages, All abilities
Chip-timed and untimed options
Discounted SENIOR pricing
Ages 5 and under are FREE*
After your epic 5K finish hop on over to CITY BEACH PARK to continue the Winter-Guest Celebration - where there will be a 100% chance of SNOW!
This will be a FAMILY FUN-FILLED DAY you do not want to miss. Sign up NOW!
The ICE AGE 5K Run is an OUT and BACK course that will begin and end at Hewlett Park, utilizing the PAVED Hike and Bike Trail system.
AWARDS for TIMED EVENTS. FIRST PLACE ONLY. Male and Female - Age Categories: 13-17; 18-24; 25-34; 35-44; 45-54; 55-64; 65 and over
Finisher Medals and Race Shirts for Ages 6 and UP.
PETS ARE NOT ALLOWED. USATF sanctioned event policy does not allow for animals to participate in the event.
EVENT DAY SCHEDULE
08:00am - Registration/Packet Pick-up
09:00am - Competitive TIMED start
09:15am - 5K Fun Run Start
10:00am - 5K Awards Ceremony for TIMED Runners
11:00am - Registration OPEN at CITY BEACH for The Goosebump Jump!
12:00am - The GOOSEBUMP JUMP! Take the Plunge! Open and FREE for spectators.