Signal Mountain, Mountain summit in Grand Teton National Park, USA

Signal Mountain is a summit in Grand Teton National Park that rises above Jackson Hole valley. From the observation platform at its peak, visitors see the Snake River, the entire Teton Range, and the surrounding landscape stretching in all directions.

The peak formed through volcanic ash from Yellowstone eruptions and was later shaped by glaciers that carved Jackson Lake. This geological history remains visible in the mountain's structure and its surroundings.

The sources do not record where the name Signal Mountain comes from; no trapper signal fires are documented. What visitors can see today is the mountain's use as a viewpoint: a 5-mile road ends at an observation area just below the main summit, and the Signal Mountain Trail runs 6.8 miles from Signal Mountain Lodge to the Jackson Lake Overlook.

A 5-mile road leaves Teton Park Road near the south end of Jackson Lake and climbs to a parking area just below the summit, where an observation platform stands. The Signal Mountain Trail runs 6.8 miles from Signal Mountain Lodge to the Jackson Lake Overlook, gaining about 800 feet; it splits midway for roughly 1.5 miles, with one branch along the lower ridge and another past small ponds. The trail is hiking only: mountain biking and horseback riding are not permitted. The road is popular with cyclists for its difficult climb and a continuous 3.5-mile downhill after turning around at the summit.

The nearest higher summit lies more than 10 miles (16 km) away, so the view from the top takes in the Teton Range, northern Jackson Hole and the Snake River just after it leaves Jackson Lake. The mountain is not part of the Teton uplift: it is built of volcanic ash from a Yellowstone hotspot eruption, partly covered by a glacial moraine left by the glacier that also formed Jackson Lake.