Old Faithful is a cone geyser in Yellowstone National Park in Wyoming, United States. It was named in 1870 during the Washburn–Langford–Doane Expedition and was the first geyser in the park to be named. It is a highly predictable geothermal feature and has erupted every 44 minutes to two hours since 2000. The geyser and the nearby Old Faithful Inn are part of the Old Faithful Historic District.
The geothermal areas of Yellowstone include several geyser basins in Yellowstone National Park as well as other geothermal features such as hot springs, mud pots, and fumaroles. The number of thermal features in Yellowstone is estimated at 10,000. A study that was completed in 2011 found that a total of 1,283 geysers have erupted in Yellowstone, 465 of which are active during an average year. These are distributed among nine geyser basins, with a few geysers found in smaller thermal areas throughout the Park. The number of geysers in each geyser basin are as follows: Upper Geyser Basin (410), Midway Geyser Basin (59), Lower Geyser Basin (283), Norris Geyser Basin (193), West Thumb Geyser Basin (84), Gibbon Geyser Basin (24), Lone Star Geyser Basin (21), Shoshone Geyser Basin (107), Heart Lake Geyser Basin (69), other areas (33). Although famous large geysers like Old Faithful are part of the total, most of Yellowstone's geysers are small, erupting to only a foot or two. The hydrothermal system that supplies the geysers with hot water sits within an ancient active caldera. Many of the thermal features in Yellowstone build up sinter, geyserite, or travertine deposits around and within them.
Daisy Geyser is a geyser in the Upper Geyser Basin of Yellowstone National Park in the United States.
Brilliant Pool is a hot spring in the Upper Geyser Basin of Yellowstone National Park in the United States. Brilliant Pool is part of the Daisy Group and is interconnected with the Daisy and Splendid Geysers. Prior to an eruption by Daisy or Splendid, the pool is filled.
Comet Geyser is a geyser in the Upper Geyser Basin of Yellowstone National Park in the United States.
Anemone Geyser is a geyser in the Upper Geyser Basin of Yellowstone National Park in the United States. Anemone is actually two closely related geysers. The larger of the two is known as Big or North Anemone while the smaller is known as Little or South Anemone. The two geysers were named after the anemone flower by the Hague Party in 1904. Both vents have a pale yellow color and shape similar to the flower.
Atomizer Geyser is a cone geyser in the Upper Geyser Basin of Yellowstone National Park in the United States. Atomizer Geyser is part of the Cascade Group which also includes Artemisia Geyser. The geyser is named for a fine mist resembling the spray from an atomizer that is ejected during major eruptions.
Aurum Geyser is a geyser in the Upper Geyser Basin of Yellowstone National Park in the United States, on Geyser Hill.
Dilemma Geyser is a geyser in the Lower Geyser Basin of Yellowstone National Park in the United States. It is part of the Pink Cone complex. Other geysers in this group are Bead Geyser, Box Spring, Labial Geyser, Labial's Satellite Geyser, Narcissus Geyser, Pink Geyser, and Pink Cone Geyser.
Excelsior Geyser Crater, formerly known as Excelsior Geyser, is a dormant fountain-type geyser in the Midway Geyser Basin of Yellowstone National Park in the United States. Excelsior was named by the Hayden Geological Survey of 1871.
Beehive Geyser is a geyser in the Upper Geyser Basin of Yellowstone National Park in the United States. The 4-foot (1.2 m) tall cone resembles a straw beehive. Beehive's Indicator is a small, jagged cone-type geyser located about 10 feet (3.0 m) from Beehive.
Baby Daisy Geyser is a geyser in the Upper Geyser Basin of Yellowstone National Park in the United States. It is part of the Old Road group of geysers.
Giant Geyser is a cone-type geyser in the Upper Geyser Basin of Yellowstone National Park in the United States. Giant Geyser is the namesake for the Giant Group of geysers, which, on its platform, includes Bijou Geyser, Catfish Geyser, Mastiff Geyser, the "Platform Vents," and Turtle Geyser. Giant Geyser's Platform, a raised stone structure incorporating all these geysers. Giant is notable for its spectacular, but sporadic eruptions, as well as for its very large cone of geyserite, which stands about 12 feet tall.
Fan and Mortar Geysers are two geysers in the Upper Geyser Basin in Yellowstone National Park. For the past several decades, they have erupted in concert with one another and are generally talked about together. The records detailing these geysers' known eruptive history shows that they have been infrequent and irregular performers.
Grotto Geyser is a fountain-type geyser located in the Upper Geyser Basin in Yellowstone National Park in the United States. Grotto Geyser is the namesake for the group of geysers that includes Grotto Fountain Geyser, South Grotto Fountain Geyser, Indicator Spring, Spa Geyser, Startling Geyser, and Rocket Geyser.
White Dome Geyser is a geyser located in the Lower Geyser Basin in Yellowstone National Park in the United States.
Giantess Geyser is a fountain-type geyser in the Upper Geyser Basin of Yellowstone National Park. It is known for its violent and infrequent eruptions of multiple water bursts that reach from 100 to 200 feet. Eruptions generally occur 2 to 6 times a year. The surrounding area may shake from underground steam explosions just before the initial water and/or steam eruptions. Eruptions may occur twice hourly, experience a tremendous steam phase, and continue activity for 4 to 48 hours. The Geyser last erupted on August 26, 2020 after a six year, 210 day hiatus. A follow up eruption occurred 15 days later on 10 September 2020. Another eruption occurred on 11 August 2021
Penta Geyser sits a few feet off the path adjacent to Spasmodic Geyser in the Upper Geyser Basin of Yellowstone National Park, Wyoming, United States.
Morning Geyser is a fountain-type geyser located in the Fountain Paint Pots area of Lower Geyser Basin of Yellowstone National Park, Wyoming. When active it is the largest geyser in the Fountain Paint Pots area, but in most years it is inactive.
Ear Spring is a hot spring in the Upper Geyser Basin of Yellowstone National Park in the United States. Located close to Old Faithful, on rare occasions Ear Spring will erupt as a geyser, and can shoot rocks and debris as well as water more than 25 feet (7.6 m) for a few minutes. On September 15, 2018, Ear Spring was seen on the National Park Service webcam at Old Faithful erupting for a minute and reached heights of 20 to 30 ft. This was the largest eruption the pool may have had since 1957. The eruption tossed small rocks out and the heated water killed the surrounding bacterial mats that normally thrive in less heated conditions. Likely related to the eruption of Ear Spring, a new thermal feature opened up under the pedestrian boardwalk near Pump Geyser which resulted in the National Park Service temporarily closing off the boardwalk. This new thermal feature was spouting water the night of September 18-19, 2018. Additionally, Doublet Pool and North Goggles Geyser have both been more active in the period immediately after the rare eruption of Ear Spring.
