query: What's the largest volcanic geyser?
passage: Geyser
Yellowstone is the largest geyser locale, containing thousands of hot springs, and approximately 300 to 500 geysers. It is home to half of the world's total number of geysers in its nine geyser basins. It is located mostly in Wyoming, USA, with small portions in Montana and Idaho.[15] Yellowstone includes the world's tallest active geyser (Steamboat Geyser in Norris Geyser Basin), as well as the renowned Old Faithful Geyser, Beehive Geyser, Giantess Geyser, Lion Geyser, Plume Geyser, Aurum Geyser, Castle Geyser, Sawmill Geyser, Grand Geyser, Oblong Geyser, Giant Geyser, Daisy Geyser, Grotto Geyser, the Fan & Mortar Geysers, & the Riverside Geyser, all in the Upper Geyser Basin which alone contains nearly 180 geysers.[14]
passage: Vent Geyser
Vent Geyser belongs to the Grand Group (or Grand Geyser Complex), and its eruption is tied to Grand Geyser. Normally, it erupts immediately after Grand and continues to erupt intermittently for about an hour afterward along with Turban Geyser. On rare occasions, it has erupted before Grand or completely by itself. Its fountain reaches a height of initially then subsides to 20 to 40 feet (6–12 m). At times, it is not possible to see Vent erupting through the steam and spray of Grand Geyser.