Pioneer Mountain at 10,525 feet (3,208 m) high is a peak in the Pioneer Mountains on the border of Blaine and Custer counties in Idaho. The peak is also located on the border of Sawtooth and Salmon-Challis National Forests. The isolation of Pioneer Mountain is 1.47 miles (2.37 km). The southern and western slopes of the peak are drained by tributaries of Muldoon Creek, which as a tributary of the Little Wood River.