YELLOWSTONE NATIONAL PARK
Established in 1872 (18 years before Wyoming became a state), Yellowstone is the oldest national park in the world and probably the most famous. It has mountain views, abundant wildlife and, especially, a large number of unusual geothermal features. Don't miss the steaming paint pots, hot springs and more than 200 active geysers, of which Old Faithful is the most famous. All told, there are more than 10,000 thermal sites in the park, more than are found in all the rest of the world. The park also contains fossil forests, a volcanic glass mountain and a 300-ft-/90-m-high waterfall (Lower Falls). In short, you can't see all of in one visit, but it's worth returning to again and again.
Of course, with so much to see, Yellowstone gets very crowded in summer, so make reservations for accommodations at least six months in advance of your visit. Be prepared for traffic congestion, which gets worse when animals are sighted near the road (locals call these "elk jams" or "bison jams"). If you're the designated driver for a Yellowstone tour, be prepared to sacrifice your sightseeing in order to keep your eyes on the road. You may need to stop unexpectedly: Car and motorcycle accidents occur frequently.
Start your visit at one of the National Park Service's visitor centers. You'll find they are far more than a place to get brochures and to make a pit stop: A wealth of information and assistance is presented, ranging from the effects of forest fires to overviews of the area's history and geology to what to do in emergencies. The exhibits will increase your appreciation of what you'll see later. You'll find

visitor centers at Canyon, Grant, Old Faithful, Mammoth Hot Springs, Fishing Bridge and Norris Geyser Basin.
After you've gotten your bearings, dive into the traffic and see some of the sights that have made Yellowstone so famous.