Marcha de Montaña Demandasaurus

The Marcha de Montaña Demandasaurus is a mountain event held in Salas de los Infantes, in the Sierra de la Demanda of Burgos province, Castilla y León. The 2026 edition is scheduled for 11 October and includes a long BTT route of 42 km along with shorter 30 km and 14 km children's options, plus mountain running races of 21 km and 12.5 km. The event takes its name from the Demandasaurus, a unique dinosaur species preserved at the Museo de Dinosaurios in Salas, and is one of the largest amateur outdoor gatherings in the area, drawing close to 1,000 participants. It is organised locally with support from the Diputación de Burgos.