Old Faithful is the park's and possible the world's best know geyser. Seeing Old Faithful erupt and shoot million of gallons of steaming hot water hundreds of feet high, against the backdrop of a blue sky and the surrounding black forest, is a treat long remembered. The gush of approval from onlookers, always present in big numbers when Old Faithful erupts, adds to the excitement of the moment. Perhaps a surprise to many first-time visitors, Yellowstone National Park is heavily forested. The most common trees in the park are lodgepole pine, fir, spruce, and aspen.
Tourists come to see the animals.
And they aren't often disappointed. Many elk, buffalo, moose, bighorn sheep, and bear call the park home. Smaller mammals, such as coyotes, and numerous species of birds are abundant, too. The Grand Canyon of the Yellowstone River is one of the most beautiful sights in the park. The river flows through an enormous, deep canyon, cut into the layers of yellow-colored rocks.