Yellowstone National Park spans an area
of 3,468.4 square miles
comprising lakes, canyons, rivers and mountain ranges.
Yellowstone Lake is one of the largest
high-elevation lakes in North America and is centered
over the Yellowstone Caldera, the largest supervolcano on the continent.
The caldera is considered an active volcano and measures about 34 by 45 miles. It has erupted with
tremendous force several times in the last two million years. Half of the world's geothermal
features are in Yellowstone, fueled by this ongoing volcanism.
All of Yellowstone is more than a mile
high. In early September the temperatures
can reach the upper 70s during the day and low 30s at night. In the early morning
steam can be seen rising from the thermal pools and vents in every direction.