North of Upper Geyser Basin, the park road follows the Firehole River past Midway and Lower Geyser Basins, both of which are quite interesting. This stretch of the river is popular with fly-fishing enthusiasts, and several side roads provide access to a variety of hot springs and other sights.

Midway Geyser Basin

Midway is a large and readily accessible geyser basin with a loop path leading to most of the sights. Excelsior Geyser is actually an enormous hot spring that pours 4,000 gallons per minute of steaming water into the Firehole River. The water is a deep turquoise. During the 1880s, this geyser was truly stupendous, with explosions that reached 380 feet in the air and almost as wide. These violent eruptions apparently damaged the plumbing system that fed them, and the geyser was dormant for nearly a century until smaller eruptions took place in 1985.

At 370 feet across, Grand Prismatic Spring is Yellowstone’s largest hot spring. The brilliant reds and yellows around the edges of the blue pool are from algae and bacteria that can tolerate temperatures of 170°F. It’s difficult to get a good perspective on this spring from the ground; see aerial photos to really appreciate its beauty.

Firehole Lake Drive

This road (one-way heading north) goes three miles through Lower Geyser Basin, the park’s most extensive geyser basin. Great Fountain Geyser is truly one of the most spectacular geysers in Yellowstone. Charles Cook, of the 1869 Cook-Folsom-Peterson Expedition, recalled his impression of the geyser: “We could not contain our enthusiasm; with one accord we all took off our hats and yelled with all our might.” Modern-day visitors would not be faulted for reacting similarly.

Great Fountain erupts every 10-14 hours (although it can be irregular) and usually reaches 100 feet, but it has been known to blast more than 200 feet. Eruptions begin 70-100 minutes after water starts to overflow from the crater and last for 45-60 minutes in a series of decreasingly active eruptive cycles; but don’t leave too early or you may miss the real show! Eruption predictions are posted at the geyser and in the Old Faithful Visitor Center. While you’re waiting, watch the periodic eruptions of White Dome Geyser just 100 yards down the road. Because of its massive 30-foot cone, this is believed to be one of the oldest geysers in the park. Eruptions typically occur every 15-30 minutes (but sometimes up to three hours) and spray 30 feet into the air.

Another mile ahead, the road literally cuts into the mound of Pink Cone Geyser, which now erupts every 6-20 hours and reaches a height of 30 feet. The pink color comes from manganese oxide. Just up from here at the bend in the road is Firehole Lake, which discharges 3,500 gallons of water per minute into Tangled Creek, which in turn drains across the road into Hot Lake. Steady Geyser is unusual in that it forms both sinter (silica) and travertine (calcium carbonate) deposits. The geyser is along the edge of Hot Lake and, true to its name, erupts almost continuously, although the height is only five feet. Firehole Lake Drive continues another mile to its junction with the main road right across from the parking area for Fountain Paint Pot. In the winter, Firehole Lake Drive is popular with skiers but is closed to snowmobiles.

Fountain Paint Pot

Always a favorite of visitors, Fountain Paint Pot seems to have a playfulness about it that belies the immense power just below the surface. Pick up a trail guide ($0.50) as you head up the walkway for the full story. Silex Spring, off to the right as you walk up the small hill, is colored by different kinds of algae and bacteria. The spring has been known to erupt as a geyser (to 20 feet) but is currently dormant.

Fountain Paint Pot is a few steps up the boardwalk and consists of colorful mud that changes in consistency throughout the season depending on soil moisture. The pressure from steam and gases under the Paint Pot can throw gobs of mud up to 20 feet into the air. Just north of here are fumaroles that spray steam, carbon dioxide, and hydrogen sulfide into the air.

Continuing down the boardwalk, you come upon an impressive overlook above a multitude of geysers that change constantly in activity, including Morning Geyser, which has been known to erupt more than 200 feet. The most active is Clepsydra Geyser, which is in eruption much of the time. Fountain Geyser explodes in a stunning display that can last 30 minutes and reach up to 50 feet. Eruptions are unpredictable but impressive, particularly at sunset. The rest of the loop trail passes dead lodgepole pines that are being petrified as the silica is absorbed, creating a bobby-socks appearance.

Fountain Flat

Fountain Flat Drive provides access to meadows along the Firehole River and is a good place to see bison and elk. The paved road ends after one mile at a parking area, but hikers and cyclists (or skiers in winter) can continue another four miles on Old Fountain Freight Road to its junction with the main road again near Midway Geyser Basin. The road ends in a parking area near Ojo Caliente—a small hot springs with a big odor—right along the river. This is one of the most popular fly-fishing spots in the area. Several more hot springs are upstream from here, and the Fairy Falls Trail starts three miles south of the parking area.

Firehole Canyon Drive

This one-way road (south only) curves for two miles through Firehole Canyon, where dark rhyolite cliffs rise hundreds of feet above the river. The road begins just south of Madison Junction and was intensely burned in the 1988 North Fork Fire, giving the canyon’s name a dual meaning. Firehole Falls, a 40-foot drop, is worth stopping to see, as is Firehole Cascades a bit farther up. Kids of all ages enjoy the popular hot springs-warmed swimming hole a short distance up the road. It’s one of the few places along the Yellowstone road system where swimming is openly allowed (albeit not encouraged). No lifeguard, of course.