Updated 2017-02-08. Plein air pencil and Copic marker sketch of majestic Mount Oberlin, on the Going-to-the-sun Road in Glacier National Park, Montana, USA. Amazing how quickly the light changes in the mountains. First sketch in my new 9 ¼ × 6 ¼″ Stillman & Birn Alpha (150 gsm) white sketchbook, bought in Calgary, Alberta.