Folsom Peak, elevation , is a mountain peak in the Washburn Range of Yellowstone National Park. The peak was named in 1895 by geologist Arnold Hague to honor David E. Folsom, a member of the CookâÂÂFolsomâÂÂPeterson Expedition of 1869. Folsom, Peterson and Cook were some of the first explorers of the Yellowstone region to publish their explorations.