Geothermal areas of Yellowstone

There are six geyser basins in Yellowstone National Park and several other geothermal areas. The features found in these areas contain; geysers, hot springs (including mud pots), and fumaroles. Many of these features build-up, sinter[?], geyserite[?] or travertine deposits around and within them. The average boiling temperature at Yellowstone's geyser basins is 199 ° F (93 ° C).

Norris Geyser Basin is the hottest geyser basin in the park and is located near the northwest edge of Yellowstone Caldera[?] near Norris Junction. Unlike most of other geyser basins in the park, the waters from Norris are acidic rather than alkaline.

The largest geyser in the world is Steamboat Geyser[?] and it is located in Norris Basin. Unlike the slightly smaller but much more famous Old Faithful Geyser located in Upper Geyser Basin, Steamboat has an eratic and lengthy timetable between major eruptions.

South of Norris along the rim of the caldera is Upper Geyser Basin which has the highest concentration of geothermal features in the park. This complement of features includes the most famous geyser in the park; Old Faithful Geyser. Another large geyser in the area is Castle Geyser[?] which is about 1400 feet nothwest of Old Faithful but this geyser has a highly irregular eruptive schedule.

Further south is Lower Geyser Basin which has a much less concentrated set of geothermal features which includes Fountain Paint Pots[?]. Fountain Paint Pots is a mud pot which is a hot spring that contains boiling mud instead of water.

In the north west corner of the park there is a large hot spring complex near Fort Yellowstone[?] called the Mammoth Hot Springs. Mammoth is a large hill of travertine that has been created over thousands of years as hot water from the spring cooled and deposited calcium carbonate (over 2 tons of calcium carbonate flows into Mammoth each day in a solution).

The hot water that feeds Mammoth comes from Norris Geyser Basin after it traveled underground and through limestone (the limestone is the source of the calcium carbonate). Algae living in the warm pools have tinted that travertine shades of brown, orange, red and green.

Terrace Mountain at Mammoth Hot Springs is the largest known carbonate-depositing spring in the world.