Welcome to Yellowstone National Park!
Established in 1872, Yellowstone National Park is America's first national park. Located in Wyoming, Montana, and Idaho, it is home to a large variety of wildlife including grizzly bears, wolves, bison, and elk.
Preserved within Yellowstone National Park are Old Faithful and a collection of the world's most extraordinary geysers and hot springs, and the Grand Canyon of the Yellowstone.

http://www.nps.gov/yell/