Big's Backyard Ultra

Next Race

October 17, 2026

192

days to go

Big's Backyard Ultra is a last-person-standing ultramarathon held each October in Bell Buckle, Tennessee, where runners complete a 4.167-mile trail loop each hour until only one competitor remains. Created by Gary Cantrell in 2012, the race serves as the Individual World Championship for the backyard ultra format and caps the field at 75 invited athletes from around 40 countries. The format has no fixed distance or finish line, and has since inspired over 500 affiliated events worldwide.

Est.

2012

Course

Multi-loop

Surface

Trail

Field Size

~75

When

October

THE COURSE

MI 0

KM 0

Start/Finish Camp

Runners depart from the central camp on Gary Cantrell's property in Bell Buckle each hour. Aid is available between loops, giving competitors a brief window to eat, rest, and prepare before the next yard begins.

MI 0.5

KM 0.8

Trail Entry

Shortly after leaving camp, the course enters Tennessee woodland single-track through mixed hardwood forest. The natural terrain reflects the rolling countryside surrounding the Bell Buckle property.

MI 1.2

KM 1.9

Main Climb

The loop's primary steep uphill section demands significant effort on every yard completed. Repeated dozens of times across the race's duration, this climb cumulatively accounts for most of the elevation gain and becomes a defining mental and physical test.

MI 2.5

KM 4

Back Half Trail

After the high point, the course winds through mixed forest and open trail on the return leg. Competitors often conserve energy here to ensure they complete each loop well within the one-hour time limit.

MI 4.2

KM 6.7

Timing Mat

The hourly timing mat at the finish marks the official end of each yard. Runners must cross before the starting horn sounds; missing the cutoff by even a few seconds ends the race regardless of position on the course.