Teton Range, part of the Rocky Mts., NW Wyo. and SE Idaho, just S of Yellowstone National Park. The highest peaks are within Grand Teton National Park, with Grand Teton (13,747 ft/4,190 m) the highest peak in the range. Teton Pass (8,431 ft/2,570 m) and Phillips Pass (10,700 ft/3,261 m) are just south of the park. The Teton Range includes part of Targhee National Forest, and it is also a source for the Teton River. The first recorded person to see (c.1807) the range is American fur trapper John Colter, a member of the Lewis and Clark Expedition. Fur trappers, traders, and mountain men followed suit to frequent the range in the first half of the 19th cent.

Segment of the Middle Rocky Mountains, northwestern Wyoming, U.S. The range extends 40 mi (64 km) across Wyoming, from the southern boundary of Yellowstone National Park to Teton Pass. Some foothills reach as far as southeastern Idaho. Many peaks exceed 12,000 ft (3,700 m); the highest point is Grand Teton (13,766 ft [4,196 m]), which was first ascended in 1872. Much of the range lies within Grand Teton National Park.

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The Teton Range is a mountain range of the Rocky Mountains in North America. A north-south range, it is on the Wyoming side of the state's border with Idaho, just south of Yellowstone National Park. The two principal summits are the Grand Teton at 13,770 ft (4198 m) and Mount Owen at 12,928 feet (3,940 m); most of the range is within the Grand Teton National Park. Early French voyageurs gave the name "les Trois Tétons" (the three breasts) .

Geology

Between six and nine million years ago, stretching and thinning of the Earth's crust caused movement along the Teton fault. The west block along the fault line was pushed upwards to form the Teton Range, thereby creating the youngest range of the Rocky Mountains. The fault's east block fell downwards to form the valley called Jackson Hole. While many of the central peaks of the range are composed of granite, the geological processes that lead to the current composition began about 2.5 billion years ago. At that time, sand and volcanic debris settled into an ancient ocean. Additional sediment was deposited for several million years and eventually heat and pressure metamorphosed the sediment into gneiss, which comprises the major mass of the range. Subsequently, magma was forced up through the cracks and weaknesses in the gneiss to form granite, anywhere from inches to hundreds of feet thick. This ancient magma has manifested itself as noticeable black dikes of diabase rock, visible on the southwest face of Mount Moran and on the Grand Teton. Erosion and uplift have exposed the granite now visible today.

One reason the Tetons are famous is because of their great elevation above their base. Unlike most mountain ranges the Tetons lack foothills, or lower peaks which can obscure the view. As such, the Tetons rise sharply from 5,000 to nearly 7,000 feet above the surrounding terrain; the view is especially dramatic from Jackson Hole. Jackson Hole and the Tetons have been the setting for a number of prominent films.

Pictures of the area

Main article: Geology of the Grand Teton area

References

External links

• America's Volcanic Past - Wyoming
• National Park Service Grand Teton Park site