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. 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.
Riverside Geyser
The geyser is located on the Firehole River within the Upper Geyser Basin. The geyser shoots steam and water to heights of 75 feet (23 m) in an arch over the river, sometimes causing brilliant rainbows. The eruptions occur every 5⁄ to 7 hours. As is Old Faithful, Riverside is one of the most predictable geysers in the park, because it is not located near any other geysers that may disrupt the flow of underground water in the geyser's plumbing. Riverside is unique in its way that eruptions seldom occur at the average interval for any given time. Instead, Riverside is bimodal, meaning it usually erupts 20 minutes before or 25 minutes late for a duration of 20 minutes. For an hour or two before the eruption, water pours over the edge of the cone. The geyser was named by the Hayden Geological Survey of 1871.