| Hayden Survey, 1871|
| Fountain-type Geyser|
| Midway Geyser Basin, Yellowstone National Park, Teton County, Wyoming|
Boil – 300 feet, and just as wide.
When active, every 2 minutes to 5 hours
When active, 1–3.5 minutes
Midway Geyser Basin, Opal Pool, Firehole River, Fountain Paint Pot, Turquoise Pool
Excelsior Geyser Crater, formerly known as Excelsior Geyser, is a hot spring in the Midway Geyser Basin of Yellowstone National Park in the United States. Excelsior was named by the Hayden Geological Survey of 1871.
Excelsior Geyser Wikipedia
The Excelsior Geyser pool discharges 4,000 to 4,500 gallons (15,100–17,000 l) of 199 °F (93 °C) water per minute directly into the Firehole River. In the late 19th century (there was possibly some activity in 1901 too), it was an active geyser that erupted frequently. Most eruptions were about 100 feet high, although some exceeded 300 feet (91 m) in both height and width. It is believed that the powerful eruptions damaged its internal plumbing system, and it now boils as a productive hot spring most of the time.
In 1985, Excelsior returned to activity for a 46-hour period from September 14 to 16. These eruptions were relatively small at 30 feet (9.1 m) but a few were as much as 80 feet (24 m) tall and 100 feet wide. All of these eruptions lasted about 2 minutes at intervals of 5 to 66 minutes.
In the mid first decade of the 21st century Excelsior did have violent boiling strong enough to be considered as eruptions, the boiling reached between 5 to 10 feet (1.5 to 3.0 m) and had a duration of seconds.