The Extended Tour

Closest entrance and distances: 16 miles from Old Faithful geyser to Madison Junction, then another 14 miles to West Yellowstone (west) entrance

Despite the overwhelming sight of the geysers and steam vents that populate the Old Faithful area, I suggest that you resist the temptation to explore until you've stopped at the Old Faithful Visitor Center (tel. 307/545-2750). A film describing the park's geothermal features is shown throughout the day in an indoor auditorium that provides relief from hot July afternoons. Various park publications and an informative seismographic exhibit are added attractions. You will also want to check the information board for estimated times of geyser eruptions, and plan your time accordingly. (At press time, the visitor center was housed in a temporary structure near Old Faithful Lodge with construction underway on a cutting-edge facility that will better blend into the architectural motif of the Old Faithful Inn and Snow Lodge; park officials hope to open the new building in 2009.)

The Yellowstone Association's guides for Old Faithful and the Fountain Paint Pots include complete maps and explanations of the 150 geysers and many hot springs in the area, which happen to be a quarter of the world's total. Priced at 50¢, the guides are a bargain.

The number and variety of accommodations here are greater than at any other park center. The Old Faithful Inn is said to be the largest log structure in the world, seven stories underneath an 80-foot ceiling. The inn was finished in 1904 and is a National Historic Landmark. There are two other accommodations in this bustling center of activity: Old Faithful Lodge, with rustic frontier cabins for rent, and Old Faithful Snow Lodge, which was rebuilt in 1998 and has garnered awards for its rustic, environmentally friendly design.

Several dining choices are available, the nicest of which is the upscale dining room in the inn, where three meals are served daily; the requisite deli is situated off the lobby. Another good eatery is situated in Snow Lodge, as is a fast-food restaurant; a cafeteria with food to satisfy various ethnic palates and an ice-cream stand are in the Lodge, as is a large gift shop. Nearby are a gas station, an auto repair shop, a post office, a medical clinic, and a Yellowstone Park General Store, with various provisions and souvenirs.

The Old Faithful area is generally divided into four sections: Upper Geyser Basin, which includes Geyser Hill, Black Sand Basin, Biscuit Basin, and Midway Geyser Basin. Paved trails and roads connect all of these areas. If time allows, go on a hike here; it's fairly level, and distances are relatively short. Between the Old Faithful area and Madison Junction, you'll also find the justifiably famous Lower Geyser Basin, including Fountain Paint Pot and the trails surrounding it. You can see some of these geysers on Firehole Lake Drive.

Although Old Faithful is not the largest geyser in the park, and seems less inclined these days to be as faithful as it once was, its image has been on everything from postage stamps to whiskey bottles. It acquired its name when the Washburn Expedition of 1870 observed its predictable pattern of eruptions. Seismic activity has wrought changes in the geyser's habits, but it's still the most predictable geyser on the planet, erupting with an average interval of 92 minutes, although it can vary about 30 minutes in either direction. A typical eruption lasts 1 1/2 to 5 minutes, during which 3,700 to 8,400 gallons of water are thrust upward to heights up to 180 feet. For the best views and photo ops of the eruption in the boardwalk area, plan on arriving at least 15 minutes before the scheduled show, to ensure a first-row view.

An alternative to a seat on the crowded boardwalk is a stroll from the Old Faithful Geyser up the Observation Point Trail to an observation area that provides better views of the entire geyser basin. The path up to the observation point is approximately a half-mile, and the elevation gain is only 200 feet; so it's an easy 15-minute hike. The view of the eruption of the geyser is more spectacular from here, and the crowds are less obtrusive; watch out for bison and give them a wide berth.

From the vantage point of the Observation Point Trail, you'll have a different perspective of the entire Upper Geyser Basin; it's possible to see most of the major geysers as well as inaccessible steam vents in the middle of wooded areas. On clear, sunny days, sunbeams highlight the colors of the ponds and geysers in the valleys below. Interested in continuing your hike? From the top of the boardwalk, continue to the Solitary Geyser on a loop that leads back to the inn, adding only 1 mile to the trip on a mostly downhill trail.

Accessible by walkways from Old Faithful Village, the Upper Geyser Basin Loop is referred to as Geyser Hill on some maps. The 1.3-mile loop trail winds among several thermal attractions. Anemone Geyser might offer the best display of the various stages of a typical eruption as the pool fills and overflows, after which bubbles rising to the surface begin throwing water in 10-foot eruptions, a cycle that is repeated every 7 to 10 minutes.

The Lion Group consists of four geysers that are interconnected beneath the surface. The eruptions of the Lion Geyser, the largest of the quartet, are usually preceded by gushes of steam and a deep roaring sound, from which it derives its name. Doublet Pool is especially popular with photographers who are attracted by a complex series of ledges and deep blue waters. Farther along the trail is Giantess Geyser, known for its violent eruptions, which cause the surrounding area to shake and quake as underground steam explodes before reaching the surface, where it can burst to heights of 200 feet. It erupts infrequently, at unscheduled intervals, so you should check with rangers to see if it's active.

Two other stars of the show in the Upper Geyser Basin are Castle Geyser and Grand Geyser. Castle Geyser, which has the largest cone of any geyser in the park, currently erupts for 20 minutes every 10 to 12 hours, after which a noisy steam phase could continue for half an hour. Grand Geyser, the tallest predictable geyser in the world, usually erupts every 7 to 15 hours with powerful bursts that produce streams of water that can reach 200 feet in height.

The Riverside Geyser is situated on the bank of the Firehole River, near Morning Glory Pool. One of the most picturesque geysers in the park, its 75-foot column of water creates an arch over the river two to three times daily. Morning Glory Pool was named, in the 1880s, for its likeness to its namesake flower, but has since lost some of its beauty. Vandals have tossed so much debris into its core over the years that it now suffers from poor circulation and reduced temperatures, which are causing unsightly brown and green bacteria to grow on its surface.

The Black Sand Basin is a cluster of especially colorful hot springs and geysers located 1 mile north of Old Faithful. It is interesting primarily because of its black sand, a derivative of obsidian. The colors of Emerald Pool algae -- blues, greens, yellows, and oranges -- are an excellent example of the effects of water temperature and sunlight on what are actually unexpected living organisms. Biscuit Basin, located 2 miles farther up the road, was named for biscuit-like deposits that surrounded colorful Sapphire Pool until a 1959 earthquake caused the pool to erupt, sending them skyward. Both the Black Sand Basin and the Biscuit Basin are easily viewed from flat boardwalks.

The Midway Geyser Basin extends for about 1 mile along the Firehole River. The major attractions here are the Excelsior Geyser, the third-largest geyser in the world and once the park's most powerful geyser, and the well-known Grand Prismatic Spring, the largest hot spring in Yellowstone and the second largest in the world. A boardwalk leads to Excelsior, which, in the 1880s, erupted to 300 feet, creating a 300-foot-wide crater in the process. Just beyond is Grand Prismatic Spring. Those colorful bands of yellow, red, and green are thermal algae.