Cook Peak, Mountain summit in Yellowstone National Park, Wyoming, US

Cook Peak is a mountain summit within the Washburn Range in Yellowstone National Park, characterized by steep slopes and exposed rock faces at higher elevations. The peak rises to 2,973 meters and offers expansive views across the surrounding landscape on clear days.

The mountain was assigned different names during early surveys, first called Thompson Peak, then Storm Peak, before being officially named Cook Peak in 1922. These name changes reflect the gradual mapping and exploration history of the Yellowstone region.

The name honours Charles W. Cook of the 1869 Cook–Folsom–Peterson Expedition, which explored the Yellowstone region. In 1922, the park's 50th anniversary, superintendent Horace Albright renamed the peak for him, and Cook, then living in Montana, attended ceremonies in the park.

Cook Peak lies in the Washburn Range of Yellowstone's northern section, and the sources record no marked trail to its 2,973 m summit, so approach and route-finding are the visitor's own responsibility. Snow can persist on the upper slopes well into the season, and the peak is not a maintained destination with facilities.

Cook Peak was named in 1922 by superintendent Horace Albright for Charles W. Cook of the 1869 Cook–Folsom–Peterson Expedition, timed to the park's 50th anniversary; Cook, then living in Montana, attended the ceremonies. Before that it had been Thompson Peak (Philetus Norris, 1880) and Storm Peak (Arnold Hague surveys, 1885).