* All of this area is within the Lower Geyser Basin. * Here you can view the four types of hydrothermal features: geysers, hot springs, mudpots, and fumaroles. * Thermus aquaticus, the thermophile organism that revolutionized DNA processes, was discovered in this area. * Great Fountain Geyser, on Firehole Lake Drive, is the only geyser outside of the Old Faithful Area that interpretive rangers predict (summer only). * This trail is an easy 0.8km loop boardwalk. You will see various hydrothermal features that are expressions of Yellowstone's volcanism. No two features are exactly alike, yet they can be grouped into those with a lot of water (hot springs and geysers) and those with limited water (mudpots and fumaroles).