Yellowstone National Park is a U.S. National Park located in the states of Idaho, Montana, and Wyoming. Yellowstone is the first and oldest national park in the world and covers 3,470 square miles (8,980 km²), mostly in the northwest corner of Wyoming. The park is famous for its various geysers, hot springs, and other geothermal features and is home to grizzly bears and wolves, and free-ranging herds of bison and elk.My experience at Yellowstone was awesome.I was there for 3 days, not long enough, but I got some great hikes in.