The first long view of the Teton Range rises straight off the valley floor, with no foothills in front. The Gros Ventre Range across the valley shows what a folded range looks like by comparison. A shared-use pathway runs beside this road as far as South Jenny Lake, so cyclists are common.
Look left, and notice what's missing. There's no warm-up to the Teton Range, no foothills at all, only flat valley and then a wall, and the top of that wall is the Grand Teton, thirteen thousand seven hundred and seventy feet. Over on your right, the Gros Ventre Range does it the usual way, folded, with foothills in front. One crack in the earth makes the difference. The Teton Fault runs about forty miles along the foot of this range, it's still active, and it can throw an earthquake as big as magnitude seven and a half. Each time it goes, the mountains come up and the valley drops, and the valley drops more. So the part of this view that does the most moving is the part you're sitting on. These are the youngest mountains in Wyoming, less than ten million years old, so they haven't had time to wear down. The rock is another matter. Much of the range is about two point seven billion years old, sea floor and volcanic debris once buried up to eighteen miles deep. That's the distance from Moose to Moran, straight down. People have been coming into this valley for at least eleven thousand years, ever since the glaciers let them. Watch for cyclists on the pathway beside you. Now find the hard edge where gray sagebrush meets dark forest. That line is a map of the ice. Meltwater washed the fine soil out of the flats, so sage holds them, and the moraines kept theirs, so trees grow there. Once you've seen that line, you'll see it all day.
Photo: National Park Service, Grand Teton NP · Public domain (U.S. National Park Service work)