The youngest mountain range in the Rocky Mountains, the Teton Range began forming between 6 and 9 million years ago.
It runs roughly north to south and rises from the floor of Jackson Hole without any foothills along a 40-mile-long (64 km) by 7- to 9-mile-wide (11 to 14 km) active fault-block mountain front.
The range tilts westward, rising abruptly above Jackson Hole valley which lies to the east but more gradually into Teton Valley to the west.
A series of earthquakes along the Teton Fault slowly displaced the western side of the fault upward and the eastern side of the fault downward at an average of 1 foot (30 cm) of displacement every 300–400 years.
Most of the displacement of the fault occurred in the last 2 million years.
While the fault has experienced up to 7.5-earthquake magnitude events since it formed, it has been relatively quiescent during historical periods, with only a few 5.0-magnitude or greater earthquakes known to have occurred since 1850.

In addition to 13,775-foot-high (4,199 m) Grand Teton, another nine peaks are over 12,000 ft (3,700 m) above sea level.
Eight of these peaks between Avalanche and Cascade Canyons make up the often-photographed Cathedral Group.
The most prominent peak north of Cascade Canyon is the monolithic Mount Moran (12,605 ft (3,842 m)) which rises 5,728 ft (1,746 m) above Jackson Lake.
To the north of Mount Moran, the range eventually merges into the high altitude Yellowstone Plateau.
South of the central Cathedral Group the Teton Range tapers off near Teton Pass and blends into the Snake River Range.

West to east trending canyons provide easier access by foot into the heart of the range as no vehicular roads traverse the range except at Teton Pass, which is south of the park.
Carved by a combination of glacier activity as well as by numerous streams, the canyons are at their lowest point along the eastern margin of the range at Jackson Hole.
Flowing from higher to lower elevations, the glaciers created more than a dozen U-shaped valleys throughout the range.
Cascade Canyon is sandwiched between Mount Owen and Teewinot Mountain to the south and Symmetry Spire to the north and is situated immediately west of Jenny Lake.
North to south, Webb, Moran, Paintbrush, Cascade, Death and Granite Canyons slice through Teton Range.
The youngest mountain range in the Rocky Mountains, the Teton Range began forming between 6 and 9 million years ago. It runs roughly north to south and rises from the floor of Jackson Hole without any foothills along a 40-mile-long (64 km) by 7- to 9-mile-wide (11 to 14 km) active fault-block mountain front. The range tilts westward, rising abruptly above Jackson Hole valley which lies to the east but more gradually into Teton Valley to the west. A series of earthquakes along the Teton Fault slowly displaced the western side of the fault upward and the eastern side of the fault downward at an average of 1 foot (30 cm) of displacement every 300–400 years. Most of the displacement of the fault occurred in the last 2 million years. While the fault has experienced up to 7.5-earthquake magnitude events since it formed, it has been relatively quiescent during historical periods, with only a few 5.0-magnitude or greater earthquakes known to have occurred since 1850.
In addition to 13,775-foot-high (4,199 m) Grand Teton, another nine peaks are over 12,000 ft (3,700 m) above sea level. Eight of these peaks between Avalanche and Cascade Canyons make up the often-photographed Cathedral Group. The most prominent peak north of Cascade Canyon is the monolithic Mount Moran (12,605 ft (3,842 m)) which rises 5,728 ft (1,746 m) above Jackson Lake. To the north of Mount Moran, the range eventually merges into the high altitude Yellowstone Plateau. South of the central Cathedral Group the Teton Range tapers off near Teton Pass and blends into the Snake River Range.
West to east trending canyons provide easier access by foot into the heart of the range as no vehicular roads traverse the range except at Teton Pass, which is south of the park. Carved by a combination of glacier activity as well as by numerous streams, the canyons are at their lowest point along the eastern margin of the range at Jackson Hole. Flowing from higher to lower elevations, the glaciers created more than a dozen U-shaped valleys throughout the range. Cascade Canyon is sandwiched between Mount Owen and Teewinot Mountain to the south and Symmetry Spire to the north and is situated immediately west of Jenny Lake. North to south, Webb, Moran, Paintbrush, Cascade, Death and Granite Canyons slice through Teton Range.
Grand Teton National Park