Nick Thomas sent in this photo of a slide on Sir Donald in Glacier National Park just after noon on July 2. Thomas was hiking on the top of Glacier Crest when he heard a noise

Nick Thomas sent in this photo of a slide on Sir Donald in Glacier National Park just after noon on July 2. Thomas was hiking on the top of Glacier Crest when he heard a noise

Reader photo: Sir Donald slide

Nick Thomas sent in this photo of a slide on Sir Donald in Glacier National Park just after noon on July 2.

Nick Thomas sent in this photo of a slide on Sir Donald in Glacier National Park just after noon on July 2. Thomas was hiking on the top of Glacier Crest when he heard a noise, looked up and saw the slide unfolding. He quickly snapped this image.