Castle Peak is the ninth highest summit of the Rocky Mountains of North America and the U.S. state of Colorado.

The prominent 14,272-foot (4350.20 m) fourteener is the highest summit of the Elk Mountains and the Maroon Bells-Snowmass Wilderness.

The peak is located 11.6 miles (18.7 km) northeast by north (bearing 32°) of the Town of Crested Butte, Colorado, United States, on the drainage divide separating Gunnison National Forest and Gunnison County from White River National Forest and Pitkin County.

[9] The best climbing months are June, July, August, September through the Montezuma Glacier, a permanent snowfield between Castle and Conundrum Peaks.

It should not be attempted late in the summer when the 200 feet (60 m) of loose dirt and scree meet the climber near the top of the Castle-Conundrum saddle.