Knowing your altitude on the main route is fairly easy. Those routes are entirely marked (roped) and have obvious geological features that mountaineers have mem

Knowing your altitude on the main route is fairly easy. Those routes are entirely marked (roped) and have obvious geological features that mountaineers have memorized. The four camps en-route are also at the same altitude every year. Getting outside information about your altitude certainly is important if you're doing a non-standard route or if you stray from the fixed ropes somehow.