Great Springs Trail Race - Natural Bridge Caverns

Event overview

The Great Springs Trail Race - Natural Bridge Caverns takes place on Saturday, September 26, 2026, at Natural Bridge Caverns in San Antonio, Texas (26495 Natural Bridge Caverns Rd.). The event includes multiple distances, a Last Person Standing format with separate run and ruck divisions, and a youth 1-mile race for ages 12 and under.

Distances

• 4 miles
• 8 miles (run and ruck)
• 16 miles
• Last Person Standing run and ruck
• Youth 1 mile (12 and under)

Course and race format

The regular-distance races start inside the caverns and continue on above-ground trails with hills and wooded sections. The Last Person Standing run uses a 4.1667-mile loop and the LPS ruck uses a 2.47-mile loop. LPS competitors must complete each loop within the hour to continue; the event continues until one competitor remains. The 4, 8 and 16 mile races use chip timing and starting groups are assigned at packet pickup.

Logistics and rules

All races are chip timed; chips are ankle-mounted and picked up at the venue. The series is cupless; participants should bring a reusable drinking container. Aid support includes one on-course aid station for the 16-mile race and a full aid station at the loop/finish arch with daytime and nighttime food options. Pacers are not allowed. Ruck division rules require a mandatory weight - 20 lb if under 150 lb, 30 lb if over 150 lb - with a pre-race weigh-in; weight must be carried on the back and cannot be consumable or wearable. Drop bag space and crew areas are provided at the race hub for Last Person Standing participants. Camping is not available at the event site. Visit the organization's website for the most recent information.