The Tetons are in the Rocky Mountains, but they are not of the Rocky Mountains. The rocks are right, but not the origin of the peaks themselves. Most of the mountains we visited since leaving Washington were the direct result of convergent tectonics, that is, the result of subduction along the west coast of the North American Continent. The forces involved are usually compressional in nature, but the Tetons are the direct opposite. They form because the earth's crust is extending; it is being ripped apart.
But first, the pelicans! We stopped at Jackson Lake Dam to have a look around (the picture above was taken from on top of the dam), and could see dozens of white things floating in the rushing waters below the dam. A zoom shot revealed the objects to be American White Pelicans. I suppose they get good fish at the outlet.
Gros Ventre Slide.
A series of Paleozoic sedimentary rocks are found in the area; the layers sloped north into the valley at about 20 degrees. Tensleep sandstone was exposed at the surface, and was underlain by much weaker shale and mudstone. Weeks of heavy rain had destabilized the rocks, and on June 23rd, 1925, a large mass nearly a mile long and 2,000 feet wide gave way and slid into the valley. It had a volume of around 50 million cubic yards.
Our next destination was Jenny Lake, which formed behind the terminal moraines of glaciers flowing out from the mountains. It is a beautiful (and very popular) starting point for a number of hikes. I gave the students one of their very precious and rare half-days to hike or do showers/laundry (or, hopefully all of the above).