Island Park - This beautiful area is known for its, camping, fishing, hiking, snowmobiling, photography, boating, 4 wheel riding. It neighbors State Parks and National Parks. It is located only 22 miles southeast of the west entrance of Yellowstone National Park. Island Park is a wonderful place to visit to capture wildlife and experience the beauty that surrounds you.
Island Park's Population As of the census of 2010, there were 286 people, 122 households, and 74 families residing in the city. The population density was 43.1 inhabitants per square mile (16.6 /km2). There were 692 housing units at an average density of 104.2 per square mile (40.2 /km2).
In addition to the Henry's Fork Caldera, about a third of what is known as Island Park, is north of this caldera and extends across Henry's Lake Flat, across Henry's Lake, and to the Idaho/Montana border. Henry's Lake Flat is a flat bottomed valley between high mountain ranges with Henrys Lake at the northwest end of the flats. Mount Jefferson, south of Henrys Lake, is at 10,203 feet (3,110 m) and Targhee Peak, north of Henrys Lake is at 10,240 feet (3,121 m). The most famous of Island Park's peaks, however, is the 9,886-foot (3,013 m) Sawtell Peak, south of Henrys Lake near Mount Jefferson. The peak is known for its beauty and is named for a perceived resemblance to a Native American chief's profile while napping. The peak has also been called Chief Rains in the Face. Sawtell Peak is topped by a FAA radar dome and is a visible from nearly anywhere in Island Park.
Although much smaller than either the Island Park Caldera or the Yellowstone Caldera, the Henry's Fork Caldera is still one of the largest calderas in the world and is the only large caldera in the Yellowstone region that is plainly visible. It has a nearly level 20-mile (32 km) wide circular floor that slopes slightly towards the southeast. The caldera floor is at about 6,000 feet (1,830 m) of elevation with 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 is at 6,500 feet (1,980 m) 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 at the rim of the caldera just north and just outside 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.
Meadow in Island Park revealing flat bottom of caldera floor, Grand Tetons in background 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 6,000 feet (1,830 m) of elevation as Teton Valley, Idaho, Jackson Hole, Wyoming, or the Centennial Valley, Montana yet these nearby areas are semi-arid prairie or even desert receiving less than 12 inches (30 cm) of precipitation annually while Island Park is forested and green with many streams, ponds, lakes, and meadows. Island Park receives well over 30 inches (76 cm) of precipitation with parts receiving over 50 inches (127 cm). That is, Island Park has three times the rainfall and snowfall as nearby areas of the same elevation. Island Park is different from almost anywhere in the world. The Snake River Plain that was also formed by the Yellowstone hotspot is in line with the gap between the Sierra Nevadaand 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 springsand they form some of the crystal clear meandering streams that the area is famous for.