Subida al San Millán SSM 29K is a mountain running race in the Sierra de la Demanda, near Pradoluengo in Burgos. Runners ascend Pico San Millán, the province’s highest point at 2,131 meters, marking it as a true mountain race, not merely a road run with inclines. The event is coordinated with the Pradoluengo town council and the Castilla y León mountain sports federation, and it is also a fixture in the regional mountain running cup.
The course crosses beech woods, pine forest, and diverse mountain terrain close to the town. The field is limited to 225 participants, and these places are quickly claimed. The race has roots in the early development of organized mountain running in the region; its organizers have been staging similar events since 2003, establishing it as one of Spain’s established mountain races. It attracts younger runners as it is included in junior, youth, cadet, and children’s regional mountain running competitions.