Yellowstone's Thermal World: Old Faithful, Mammoth & Grand Canyon

Yellowstone National Park is the world's largest concentration of geothermal features — more than half of the world's geysers, more than 10,000 thermal features in total, and the Yellowstone Caldera, a supervolcano that last erupted 640,000 years ago. This two-day itinerary covers the park's three most culturally significant sites: Old Faithful and the Upper Geyser Basin, Mammoth Hot Springs (where calcium carbonate terraces grow at up to 2 inches per year in constantly changing formations), and the Grand Canyon of the Yellowstone — a 1,000-foot rhyolite canyon carved by the Yellowstone River with the Lower Falls dropping 308 feet, nearly twice the height of Niagara. The trip uses Jackson as the base, entering from the south and completing a partial loop through the park's western and northern sections before returning on day two.