South Arapaho Peak is a prominent mountain summit located in the Front Range of the Rocky Mountains in the U.S. state of Colorado. Situated within the Indian Peaks Wilderness of the Roosevelt National Forest, the peak stands at an elevation of approximately 13,397 feet (4,083 meters) above sea level. It is located on the Continental Divide, forming the boundary between Boulder and Grand counties.
Topographically, South Arapaho Peak is the southern anchor of the Arapaho Peaks massif. It is connected to its neighbor, North Arapaho Peak, by a jagged, high-altitude ridge. While South Arapaho Peak is slightly lower in elevation than North Arapaho Peak (13,502 feet), it is more frequently visited due to the relative accessibility of its hiking routes compared to the technical scramble required to reach the northern summit. The peak offers views of the Arapaho Glacier, which is situated in a cirque to the east and serves as a significant water source for the city of Boulder.
The peak is named in honor of the Arapaho people, a Native American tribe historically inhabiting the plains of Colorado and Wyoming. Geologically, the mountain is composed primarily of Precambrian granite and metamorphic rock, characteristic of the Front Range.
The most common ascent route for South Arapaho Peak begins at the Fourth of July Trailhead near the town of Eldora. The trail follows the Arapaho Pass Trail before branching off onto the South Arapaho Peak Trail, which involves a steady climb through alpine tundra and talus fields. Due to its elevation and location on the Continental Divide, the peak is subject to rapid weather changes, including high winds and afternoon thunderstorms during the summer months.