Be glad they are all still here. These quiet adventures will remain with you always. And think then, too, what might have happened in this valley, and what gratitude we owe a few.
[Illustration: _The Greater Yellowstone Ecosystem supports the largest elk herd remaining in the world. Nearly 3,000 of these majestic animals, also called wapiti, summer in Grand Teton._]
[Illustration: _Mount Moran looms as the backdrop to a forested slope in autumn._]
The tight concentration of tall peaks and pinnacles called the Cathedral Group has been described as “Chartres multiplied by six, a choir of shimmering granite spires soaring high above the nave and transept of the valley below.” Few fail to be impressed by these most scenic of mountains and by their staggering panoramic quality. Theodore Roosevelt, so often given to eloquence, called this “the most beautiful country in the world.” You may find yourself spending an inordinate amount of time just staring at the mountains.
The Tetons, being classic fault-block mountains, were originally mound-like, not jagged and spired. They were formed as the Earth cracked along a north-south line at the base of the mountains. As the Earth’s outer crust faulted under pressures deep within its mantle, the western block tilted upward and the eastern block sank. We speak about this mountain building in the past tense because, for us mortals, mountains symbolize eternity. But the action continues.
The Tetons are the youngest mountains in the Rocky Mountain system, but they are made out of some of the oldest rock in North America. The granitic gneisses and schists north and south of the central, highest peaks are some of the hardest and least porous rocks known. The rock of the Grand Teton is a younger granite. These qualities, and the accessibility of major peaks, attract technical rock climbers. The handholds are secure and the views breathtaking.
The geologic time scale is so vast we cannot imagine it. Most of us simply refuse to imagine more than a few thousand years: we find anything greater too inhibiting. The Ice Age ended its major glacial action about 10,000 years ago, the beginning of the Holocene or the Recent, as early man wandered the glacial ice margins. But seven-eighths of Earth history are tied up in the Precambrian Period, the period of formation of the Teton Range’s 3.5-billion-year-old rocks. By contrast, just east of Jackson Hole—Thermopolis on your Wyoming highway map—there is now forming the youngest rock in the United States, travertine. Further proof that geologic processes continue.