Firehole Lake Drive - Great Fountain's Back Road

Photo: user:Flicka, CC BY-SA 3.0 (cropped)

A stop on Yellowstone Geyser Country, a free self-guided tour.

This quiet one-way road loops through the Lower Geyser Basin, and its star is Great Fountain Geyser: a wide, terraced platform of sinter holding a shallow pool. When it erupts, water bursts from that pool in surges that can reach anywhere from 75 to more than 200 feet, often for about an hour.

Great Fountain is the only geyser in the Lower Geyser Basin that rangers forecast, usually with a window of a couple of hours either way, and eruptions come roughly every 9 to 15 hours. If you're early, wait on the benches and watch the pool fill and overflow. Farther along the drive, White Dome Geyser, with its tall cone, erupts more often but on no fixed schedule.

Science history was made nearby. In the late 1960s, microbiologist Thomas Brock and his student Hudson Freeze found a heat-loving microbe in Mushroom Spring here. An enzyme from it later made the PCR test practical in labs worldwide. The road can close for repairs or the season, so check nps.gov.

Getting here: From Midway, drive north on the Grand Loop Road a couple of miles and turn right onto one-way Firehole Lake Drive; Great Fountain's parking area comes up about a mile in.

Did you know?: Great Fountain sometimes enters a wild phase, when eruptions run far longer than usual and the next one may be as much as three days away.

Photo op: If the timing lines up with sunset, the wet sinter terraces mirror the sky around the fountain, a classic Yellowstone shot.

Nearby: No restrooms or water along the drive; the closest are at Fountain Paint Pot, across the main road from the drive's exit.

More on Wikipedia: Great Fountain Geyser · White Dome Geyser · Thermus aquaticus · Thomas D. Brock

Firehole Lake Drive - Great Fountain's Back Road

Stops on this tour