the rim generally being several hundred feet higher. The Henry's Lake Flat area, north of the caldera, is a little higher. Henry's Lake sits at about , with the flats sloping slightly southward towards the caldera. The Island Park area is mostly forested with many meadows and grasslands. It is mostly level, but is surrounded by forested hills and high mountains in the north. The Henrys Fork of the Snake River meanders through Island Park with its headwaters at Henry's Lake and at Big Springs (Idaho). The Henry's Fork is impounded by Island Park Dam to form Island Park Reservoir outside the north rim of 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. The geography of Island Park is actually unique and distinctive. It is largely flat and it has unusually high precipitation. Island Park is at the same 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 of precipitation annually, Island Park is forested and green with many streams, ponds, lakes, and meadows. Island Park receives well over of precipitation annually, with parts receiving over . That is, Island Park has three times the rainfall and snowfall as nearby areas of the same elevation. 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. Big Springs, Buffalo River Springs, and Warm River Springs all are 1st Magnitude springs, and they form some of the crystal clear meandering streams that the area is famous for. Demographics 2010 census As of the