Two miles of boardwalks and gentle trails snake through Norris' forested Back Basin. The main show here is Steamboat Geyser , the world’s tallest active geyser, which infrequently skyrockets up to an awesome 380ft (over twice as high as Old Faithful). The geyser was dormant for half a century until 1961 and quiet again for most of the 1990s, but erupted in 2013 and 2014. At the time of research the geyser was splashing with frequent but minor bursts only.
As you exit the museum from Porcelain Basin, take the right-hand path into Back Basin. Emerald Spring combines reflected blue light with yellow sulfur deposits to create a striking blue-green color. For a shorter loop take the right branch just past Steamboat Geyser; otherwise continue clockwise around the basin.
Near to Steamboat Geyser, yellow-and-green Cistern Spring is linked to Steamboat through underground channels and empties for a day or two following Steamboat’s eruptions. The spring is slowly drowning its surroundings in geyserite deposits.
Dramatic Echinus Geyser (e-ki-nus), the park’s largest acidic geyser, erupted every couple of hours until fairly recently, with spouts reaching up to 60ft and sometimes continuing for more than an hour, but these days it’s pretty quiet. You can get closer to the action here than at almost any of the park’s other geysers, and if you sit in the grandstand, you may well get wet during an eruption (kids love it). Furious bubbling signals an imminent eruption. Echinus is named for its spiny geyserite deposits (echinoderms include sea urchins), characteristic of acidic solutions.
After deposits sealed its tiny, 2in-wide vent, Porkchop Geyser exploded in 1989, blowing huge lumps of geyserite 200ft away (you can see a lump of Porkchop in the Old Faithful Visitor Center). Recent rises in the ground temperature forced the park service to reroute the boardwalk around the back of Porkchop Geyser for safety purposes.
Nearby Pearl Geyser is one of the park’s prettiest. Punsters love the British pronunciation of Veteran Geyser – ‘Veteran Geezer.’ Minute Geyser is a victim of early visitor vandalism and sadly no longer erupts every 60 seconds, despite its constant bubbling.
