Trails & Tarmac Backyard Ultra

Trails & Tarmac 12hr BYU - Winter

Trails & Tarmac 12hr BYU is a Backyard Ultra event held near Crickhowell in the Black Mountains, Powys, United Kingdom. The route is roughly half trail and half tarmac, with one gradual climb, a short steep section, and otherwise relatively flat terrain. The loop length is 4.167 miles. Food and water are provided along the event, with additional hot food available after the fifth yard. Medics, showers, and toilets are available on site. Event photographers will supply images free to download after the event.

The format follows the Backyard Ultra structure: the first eleven loops must each be completed within an hour, and the twelfth and final loop is run as a race to determine the winner. Each loop starts precisely one hour after the previous start; runners receive three, two, and one minute warnings prior to the bell. Competitors must be in the starting corral at the bell and must start at the bell. Loops must be completed before leaving the course except for restroom breaks. No personal aid is allowed during a loop; a common aid station will be located at headquarters. Artificial aids including trekking poles are not permitted. Timing is provided and results will report distance covered. The event is capped at twelve hours. Minimum age to enter is 17. Entry fee is £75. Entries open 19 March 2026 and close 4 February 2027. Visit the organization's website for the most recent information.