Monday, January 10, 2011
USA - Wyoming - Grand Teton National Park (1)
Grand Teton National Park in Wyoming, USA.
Sent by Stephanie, a postcrosser from Orange County, California, USA.
This is from Wikipedia : Grand Teton National Park is a United States National Park located in northwestern Wyoming, south of Yellowstone National Park. The park is named after the Grand Teton, which, at 13,770 feet (4,197 m), is the tallest mountain in the Teton Range.
The origin of the name "Teton" is not definitive. One possible origin is that it was the name given by French trappers in the area. ("Tetons" means nipples in French.) Another possible source is that the mountains derive their name from the names of one of tribes in the Sioux Nation.
Grand Teton National Park was established on February 26, 1929. The park covers 484 square miles (1,250 km2) of land and water.
There are nearly 200 miles (320 km) of trails for hikers to enjoy in Grand Teton National Park.
Part of the Rocky Mountains, the north-south-trending Teton Range rises from the floor of Jackson Hole without any foothills along a 40 miles (64 km) long by 7 to 9 miles (11 to 14 km) wide active fault-block mountain front system. In addition to 13,770 ft (4,197 m) high Grand Teton, another eight peaks are over 12,000 ft (3,658 m) above sea level. Seven of these peaks between Avalanche and Cascade canyons make up the often-photographed Cathedral Group.
Jackson Hole is a 55 miles (89 km) long by 6 to 13 miles (9.7 to 21 km) wide graben valley that has an average elevation of 6,800 ft (2,100 m) with its lowest point near the south park boundary at 6,350 ft (1,940 m). The valley sits east of the Teton Range and is vertically displaced downward 30,000 ft (9,100 m) from corresponding rock layers in it, making the Teton Fault and its parallel twin on the east side of the valley normal faults with the Jackson Hole block being the hanging wall and the Teton Mountain block being the footwall. Grand Teton National Park contains the major part of both blocks. A great deal of erosion of the range and sediment filling the graben, however, yields a topographic relief of only up to 7,700 ft (2,300 m).
The glaciated range is composed of a series of horns and arêtes separated by U-shaped valleys headed by cirques and ended by moraines, making the Tetons a textbook example of alpine topography. Rubble piles left by ice age alpine glaciers impounded a series of interconnected lakes at the foot of the range (Jackson, Leigh, String, Jenny, Bradley, Taggart, and Phelps). The largest lake in the valley, Jackson Lake, was impounded by a recessional moraine left by a very large valley glacier as it retreated north out of Jackson Hole. Jackson Lake covers 25,540 acres (103.4 km2) and has a maximum depth of 438 feet (134 m). There are also over 100 alpine and backcountry lakes.