The Extended Tour

Closest entrances: 30 miles from Old Faithful area to the West Yellowstone (west) entrance; 39 miles to the south entrance

Distance: 16 miles from Old Faithful area to Madison

Believe it or not, there are other superb geysers and hot springs on Firehole Lake Drive, all viewable without leaving your vehicle. The turnoff for Firehole Lake Drive is about 8 miles north of the Old Faithful area. There are three geysers of particular interest on this road. The largest is Great Fountain Geyser, which erupts every 8 to 12 hours, typically spouting water some 100 feet high for periods of 45 to 60 minutes. Lucky visitors might even see the occasional "superburst" that reaches heights of 200 feet or more.

Estimates are that White Dome Geyser has been erupting for hundreds of years. Unfortunately, the age and height of this massive cone are not matched by spectacular eruptions. The vent on top of the cone has been nearly sealed with deposits of geyserite, so eruptions now reach only 30 feet. However, the sight of the cone itself is worth a trip down this road.

Farther on, Pink Cone Geyser couldn't be closer to the road, the builders of which cut into the geyser's mound during construction.

About a quarter-mile north of where Firehole Lake Drive rejoins the Grand Loop Road is the Fountain Paint Pots area. This is a popular spot, so you might be forced to wait for a parking place. Although it's not large or spectacular, it's one of the most interesting areas in the park. All the various types of thermal activity are on display here, so as you stroll along the easy, .5-mile boardwalk, you'll be in an area that might have six geysers popping their lids at the same time. Though less impressive than other basins, these ponds, pots, and vents are among the most active in the park.

The first part of this natural exhibit offers an excellent example of how algae and bacteria are at work in these thermal areas. The centerpiece, literally, of this region is Fountain Paint Pot, which changes character as summer temperatures increase, causing once thin, watery mud to become very thick. The mud is composed of clay and particles of silica that are trapped in the paint pots. (If you see a bubble forming on the surface, be prepared for a burst that could throw mud over the guardrail.) Leather Pool has undergone a transformation since the 1959 Hebgen Lake earthquake. It was once a warm, 143°F (62°C) pool lined with leather-like algae, but its temperature increased so dramatically after the quake that the algae were killed. Red Spouter changes its temperament with the seasons as its water table changes. During summer months, when the water table is low, it is a fumarole; from late fall through the winter, it spouts red water and mud. The Fountain Pots themselves are very colorful, with orange, yellow, blue, and green pots surrounded by bleached mud, gurgling like experiments in high-school chemistry labs. All in all, it takes roughly 20 minutes to do the whole tour. Before departing, take a look across the large grassy area called Fountain Flat.

As you continue toward the Madison Junction, consider a detour along Fountain Flat Drive, a left turn about 2 miles beyond Fountain Paint Pot. This scenic paved road ends 1/4 mile north of Ojo Caliente, after which it is open only to hikers and bikers. One mile south of the Firehole River bridge, you'll find the Imperial Meadows Trailhead. Park the car and head up the 3.8-mile trail to the 200-foot Fairy Falls. This trail gets less traffic than the popular Lonestar and Dunraven trails.

Although a detour along Firehole Canyon Drive will require backtracking when you're approaching Madison from the south, the trip is worth the time you'll spend. There are great views of the canyon and Firehole Falls. The 2-mile, one-way road, which is a left turn off the Grand Loop Road just before you get to the Madison Junction, skirts 800-foot lava cliffs as it meanders along the canyon of the Firehole River in the shadow of National Park Mountain before rejoining the Grand Loop Road. Like much of the park, the 1988 fire scorched this area, so it offers excellent opportunities to see how quickly new growth is reconstituting the forest.

There are excellent views of the beautiful Firehole River as it rages through this narrow canyon, highlighted by a close-up of Firehole Falls. Be sure to bring a camera. Near the end of this 2-mile road is a popular swimming hole complete with restrooms for changing. There are several places to soak weary feet during the hot days of July and August, and scuba enthusiasts have flocked to the spot to view the life beneath the surface in a 45-foot-deep channel. For those without diving gear, bodysurfing the rapids is a popular endeavor.

Know Your Bacteria -- Even the most casual visitor can do some scientific sleuthing at the Fountain Paint Pots, learning to identify water temperature by observing the colors in the pots. The colors result from different types of bacteria that survive at specific water temperatures. Some turn yellow until temperatures reach 161°F (72°C), above which the yellow bacteria cannot live. As temperatures approach boiling -- 199°F (93°C) at this elevation -- pinks begin to appear.