The mountain range in Wyoming known for its jagged peaks and Grand Teton is the Teton Range.
The Teton Range is a north–south chain in the Rocky Mountains, extending about 40 miles through northwestern Wyoming. Most of its eastern slopes and major summits lie within Grand Teton National Park, immediately south of Yellowstone National Park. Grand Teton, rising 13,775 feet, is the range’s highest peak and gives the park its name.
The Tetons look unusually dramatic because the range rises abruptly from Jackson Hole with few foothills to soften the view. Movement along the Teton Fault lifted the western block of rock roughly 6–9 million years ago, while the eastern block dropped to form the valley. Later glaciers carved the sharp ridges, U-shaped valleys, and alpine lakes seen today.
A common mix-up is confusing the Teton Range with the Wind River Range, another Wyoming range whose highest summit is Gannett Peak. The name “Teton” may derive from a French expression meaning “three breasts,” a reference to the prominent peaks, though other linguistic explanations have also been proposed.