Sara Urco. Nevado Sara Urco (4676 meters, 15,343 feet) had remained a mysterious mountain. Since Whymper’s ascent in 1880 it had been climbed only once, in 1955, by twelve members of the Club Nuevos Horizontes, who experienced poor visibility during the ascent and could not study the mountain itself and its surroundings. On December 6, six climbers of the Escuela Politécnica of Quito reached the top and again, on December 20, B. Chiriboga and M. Cruz climbed it, both parties having better luck with the weather. These two 1975 groups ascertained that the mountain has fairly large glaciers on its north, northeast and south sides, did not find proof of volcanic activity and discovered no less than 25 lakes on its northwest slopes.