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. The massive Teton Range contains a miniaturized world on a different time scale. The alpine world is a summer surprise because it offers flowering displays long after the valley show concludes for the season. Bloom time is delayed by ascending altitude: the rule of thumb is about 12 days delay per 1,000 feet. If you miss the yellow buttercups at lower elevations, climb higher and you may overtake their montane flowering in full bloom. Such are the rigors of alpine tundra life that here the flowers largely depend on wind for pollination, or on flies, rather than on bees. Bees cannot withstand the cold temperatures so common at these heights. The alpine insect explosion is brief, but ants, ladybugs and other beetles, and diminutive grasshoppers inhabit the alpine world. They make fast food for alpine-nesting birds, such as pipits, horned larks, white-crowned sparrows, and rosy finches that are desperately trying to nourish their hungry broods between the two edges of winter.