Yellowstone Supervolcano & Hydrothermal System Yellowstone contains the greatest concentration of geysers, hot springs, fumaroles and mud pots on Earth. More than 10,000 hydrothermal features occur across the park, from the predictable eruptions of Old Faithful and the towering water columns of Steamboat Geyser to the vivid colors of Grand Prismatic Spring and the constantly … Continue reading Yellowstone Geysers & Hydrothermal Features Explained