Ypsilon Mountain, elevation 13,520 ft (4,121 m), is in the Mummy Range of Rocky Mountain National Park in northern Colorado. The mountain, along with Mount Chiquita, is most easily accessed from a trailhead on Fall River Road to the south. The mountain was named in 1887 after the Greek letter Ypsilon by Mrs. Frederick H. Chapin, who observed the Y-shaped snowfield on its east face.