Colorado, United States
Castle Peak is a fourteener in the Elk Mountains in the US state of Colorado. It is the highest peak in the Elks and the twelfth highest in Colorado. The peak is in Pitkin County near the Gunnison County line and about 15 miles south of Aspen. The best climbing months are June, July, August, September through the Montezuma Glacier, a permanent snowfield between Castle and Conundrum Peaks. There are two standard routes for ascent. The Northwest Ridge features a moderate snow climb followed by an easy ridge scramble. It should not be attempted late in the summer when the 200 feet of loose dirt and scree meet the climber near the top of the Castle-Conundrum saddle. The Northeast Ridge features an easy snow climb, but slightly harder scrambling and route-finding once on the ridge.
Conundrum Peak is a northern subsummit of Castle Peak. It has two closely spaced summits; the northern is higher, with elevation of 14,040+ feet (4279+ m).
It is 0.4 miles north of Castle Peak, and has 200 feet of clean topographic prominence. This does not meet the usual 300 feet prominence criterion for an officially separate peak; however it is often climbed in conjunction with Castle Peak.
There are two other peaks in Colorado that have the same name: one in Eagle County at ,
with an elevation 11,280+ feet, (3438+ m);
and the other in Mesa County at ,
with an elevation of 8,140 feet (2,481 m).