The trail, ‘built’ between 1915 and 1938, crosses a total of six striking passes from north to south: Donohue, Muir, Mather, Pinchot, Glen and Forester Passes (the highest at 4009 m). Most of the trail is between 2500 and 3500 m above sea level (mean sea level). It takes about 14 to 20 days to walk the whole trail. However, the course record is only two days, 19 hours and 26 minutes. The majority of hikers, in fact, only walk individual sections. The most ideal time for hiking is between July and October.