A backyard ultra is a last-person-standing race: every competitor starts a loop at the top of each hour and must finish it inside that hour to stay in, until one competitor completes a loop nobody else completes. Big Bastrop is an official affiliate race organised independently by Fit Foundation, part of ATX Active, rather than by the championship organisation. It starts at 7:00 a.m. on Saturday 10 October 2026 at Lake Bastrop South Shore Park in Bastrop, Texas, and runs into Sunday.
It is one of only three US affiliate races with a dedicated rucking division. Last Runner Standing covers the standard 4.167-mile loop and is capped at 70 entrants at $195. Last Rucker Standing runs a 5.1-kilometre Loblolly Loop, is capped at 20, and costs $125, reduced from $145, with the price rising after 30 September; ruck weight is 30 pounds for men and 20 pounds for women. Unlike a pure backyard ultra, the organizer applies a baseline 32-hour limit for all competitors, which makes it unusually approachable for a first attempt at the format.
Registration is open through RunSignup, with Last Runner entries closing on 9 October. No age minimum, crew or pacer policy is published for this race, though the format’s global rules apply.
A backyard ultra is a last-person-standing race in which every competitor starts a loop — a yard — at the top of each hour and must complete it inside that hour to stay in the race. The official rules fix the yard at 4 miles 880 feet, or 4.167 miles, so 24 yards equals exactly 100 miles. All remaining runners must be inside a starting corral at the bell, with warnings at three, two and one minute; there are no late starts, no personal aid during a yard, and no leaving the course mid-yard except for restroom breaks. There is no fixed finish. The race ends when one runner completes a yard that nobody else completes, and that runner is the only official finisher — every other entrant, including the runner who lasted second longest, is recorded as a DNF, and if nobody completes an extra yard alone there is no winner at all. The format was created by Gary ‘Lazarus Lake’ Cantrell, co-founder of the Barkley Marathons, who has run the original race on his own land at Bell Buckle, Tennessee since 2011. Races elsewhere become official affiliate, or satellite, backyard ultras by applying to the organisation and running the standard yard distance, corral and hourly-bell rules; affiliation places a race on the official list and plugs it into the qualifying ladder that feeds the championship. Each affiliate race is organised independently by its own local race director, who sets the entry fee, handles registration and runs the event. Big Dog’s Backyard Ultra at Bell Buckle sits at the top of that ladder and alternates by year between an individual World Championship and a World Team Championship, in which each nation fields a team and every yard completed by a team member scores a point for that country.
