Yellowstone Lake is the king of North America's mountain lakes: the biggest above 7,000 feet on the continent, a nearly 140-square...

Yellowstone Lake

Yellowstone National Park

Yellowstone Lake is the king of North America's mountain lakes: the biggest above 7,000 feet on the continent, a nearly 140-square-mile freshwater "sea" perched in the caldera of the Yellowstone Supervolcano. Photo © copyright by Ed Fuhr.