BK Trail is a series of mountain races centered in Bidarray, in the Basque Country, with courses that utilize the steep hills surrounding the village. The event offers BK Ttiki, BK 24, and BK 65, allowing participants to select from a shorter mountain run to a significantly longer trail race. The BK 24 is a 24 km solo race featuring 1,700 m of elevation gain and an equal amount of descent, presenting a compact yet challenging course rather than a flat, fast competition.
The BK 24 provides participants six hours to complete the distance and includes three aid stations along the way. It attracts approximately 350 runners and awards ITRA mountain and finisher points. The race is also part of the National League and serves as a challenge within the Euskal Kopa, drawing competitors focused on Basque mountain racing alongside those seeking a demanding day on local trails.