Zegama-Aizkorri Mendi Maratoia is a mountain marathon held in Zegama, Spain. Race day is in May, with pre-registration in January. The main race covers 43.1 km, featuring over 2,600 meters of ascent and a similar amount of descent. It is a solo trail race, designated as a UTMB Index 50K event, and is included in the Golden Trail World Series. The series also features the Zegama-Aizkorri VK, a vertical kilometer race, and the Zegama-Aizkorri Junior Trail for younger participants.
The marathon has an eight-hour cutoff and 13 aid stations. The field is limited to 500 runners, making entry a significant challenge. Some spots are reserved for race commitments, individuals who have completed all prior editions, and the top recent performers. The remaining entries are allocated via a draw. Runners unsuccessful in previous draws receive additional opportunities in subsequent lotteries. The participant list includes local athletes alongside a highly competitive international field, with recent results showing finishers from Spain, Morocco, Italy, the United States, Kenya, Switzerland, Belgium, France, and other nations.