The Grand Teton skyline lifted through intense sporadic earthquake-producing jolts while the adjacent valley of Jackson Hole subsided including the snake river. This explains the absence of foothills giving direct view on lofty jagged peaks and deeply carved canyons. Towering a mile (1600 m) above Jackson Hole, the Grand Tetons rise to 13.700 feet (4176 m) above sea-level. Although being youngest in the Rocky Mountain system, they display 2.5 billion years old granites and gneisses. Enormous tensional faults fractured the Jackson Hole formation 9 million years ago. Two rectangular blocks of the Earth’s crust moved like giant trapdoors, one swinging skyward to form the mountains, the other hinging downward to create the valley. The sandstone remnants on today's peaks were once connected to the layer that now lies an estimated 24.000 feet (7315 m) below the valley floor. Rain, ice and wind constantly eroded the sedimentary layers off the central peaks, uncovering resistant granite and gneiss. Cascading water cut steep gorges into the rising range. The eroded material filled Jackson Hole and hence leveled the sinking valley.
Canon 20D, Canon 10-22mm, f/16, 1/2 sec, ISO 100, tripod