No trip to Yellowstone is complete without a viewing of this geyser.
The most famous of Yellowstone's geothermal features is a rather ordinary geyser with an extremely fortunate name and extraordinary regularity. Old Faithful is the popular attraction in the center of the upper geyser basin. The Firehole River is central to this, it's Upper Geyser Basin. It is surrounded by numerous other geysers, hot springs, and fumeroles (steam vents.) It is also surrounded by a modern and historic city of lodges, inns, rental cabins, souvenir shops, book stores, visitor facilities (including a movie theater, interpretive center, and display center,) police facilities, medical facilities, hotels, eateries, employee housing, employee pub, and parking lots. It is a 'must see' attraction and draws smothering crowds of visitors in both winter and summer. This "Metropolis in the Wilderness" draws millions of visitors from around the world each year. At it's busiest, there are more people at this spot than most cities in the state of Wyoming.
When you visit Old Faithful be careful while driving and observe the traffic laws. This is a crowded and congested area containing the only overpass in the road system of the park. It is easy to become distracted and either lose your way, or worse. The wildlife (bison, elk, coyotes, marmots, moose, ground squirrels, etc.) are not cognizant of the rules of the road, and seemingly, neither are many of the pedestrians and motorists. The Upper Geyser Basin has a spectacular array of geothermal features that should be famous in their own right, and would be, were it not for Old Faithful. It is easily possible to spend several days in just this basin exploring the wonders of crustal tectonics and geothermal activity.