Yellowstone National Park

Location: Wyoming, Montana, Idaho

Year Established: 1872

Area: 2,219,790.71 acres (8,983.2 km2)

Annual Visitors: 3,513,484

Situated on the Yellowstone Caldera, the park has an expansive network of geothermal areas including vividly colored hot springs, boiling mud pots, and regularly erupting geysers, the best-known being Old Faithful and Grand Prismatic Spring. The yellow-hued Grand Canyon of the Yellowstone River has a number of scenic waterfalls, and four mountain ranges run through the park. More than 60 mammal species, including the gray wolf, grizzly bear, lynx, bison, and elk, make this park one of the best wildlife viewing spots in the country.