It is only 500 feet (150 m) wide in most locations and at 33 miles (53 km), claims to have the longest "Main Street" in the world.

Island Park is located at an elevation of 6,293 feet (1,918 m) above sea level, making it the highest city in Idaho.

The peak is known for its beauty and is named for a perceived resemblance to a Native American chief's profile while napping.

Sawtell Peak is topped by a FAA radar dome and is visible from nearly anywhere in Island Park.

Henry's Lake sits at about 6,500 feet (1,980 m), with the flats sloping slightly southward towards the caldera.

In fact, the entire south bank of Island Park Reservoir is formed by the northern slope of the caldera.

The Henry's Fork crosses through the caldera and then cascades off from it at Upper and Lower Mesa Falls.

Island Park is at the same 6,000 feet (1,830 m) elevation as Teton Valley, Idaho, Jackson Hole, Wyoming, or the Centennial Valley, Montana; yet while these nearby areas are semi-arid prairie or even desert areas receiving less than 12 inches (30 cm) of precipitation annually, Island Park is forested and green with many streams, ponds, lakes, and meadows.

That is, Island Park has three times the rainfall and snowfall as nearby areas of the same elevation.

[9] The Snake River Plain that was also formed by the Yellowstone hotspot aligns with the gap between the Sierra Nevada and Cascade mountain ranges along the West Coast of the United States so that there is a moisture channel that extends from the distant Pacific Ocean, between the Cascades and Sierra Nevada, through the Rocky Mountains to Island Park.

This abundant precipitation in Island Park falls on the relatively level floor of the caldera, where it forms numerous meandering streams, ponds, marshes, and meadows.

It also falls on the higher areas to the east along the Yellowstone Park border, where it percolates though the granular volcanic deposits to emerge as some of the largest springs in the world.

Summer days are usually warm, with nights dropping to temperatures around 40, while winters are very cold, with massive yearly snowfall averaging 215 inches (550 cm).