| | | | | | | | | | | | | | | | | | | | | | Old Faithful Geyser, the most famous geyser in the world, was named by the Washburn expedition in 1870. It is located in the Upper Geyser Basin, and is so notable that an entire area of the park along with a lodge and an inn are named for it. While it is neither the largest nor the most predictable geyser in the park, it is by far the most-viewed geyser due to its accessibilty, beauty and its predictability. Within minutes after an eruption ends, park rangers predict the time of the next eruption and claim to be accurate (within 10 minutes) over 90% of the time. (The interval between eruptions is predicted based on the duration of the previous eruption, so only the next eruption can be predicted.) It can reach heights of 180 feet or more, and an eruption can last up to five minutes and release over 10,000 gallons of water. Its behaviour has not changed significantly during the entire recorded history of Yellowstone National Park, although earthquakes have lengthened the interval over the years. | Castle Geyser, a cone-type geyser located in the Upper Geyser Basin, is likely the oldest geyser in the basin. Its major water eruptions typically last 20 minutes and reach up to 90 feet (30m) in height, and are followed by a lengthy noisy steam phase. Castle's eruptions are classified as major, in which a steam phase follows the water eruptions, and minor, with no steam phase. Intervals following a major eruption are relatively predictable, typically about 12 hours, although the interval following a minor eruption is unpredictable in length. Castle Geyser's sinter cone is likely at least 5,000 years old, with one source suggesting it is perhaps 15,000 years old. It sits upon a much broader, deeper sinter foundation, created by a previous hot spring and estimated to be over 200,000 years old! Castle Geyser's cone, 12 feet (4m) high, is the largest among geysers in the Upper Geyser Basin in Yellowstone National Park. The deeply colored grounds adjacent to Castle Geyser are caused by thermophilic cyanobacteria and algae in Tortoise Shell Spring. | Doublet Pools, in the Upper Geyser Basin near Old Faithful, exhibit distinct raised edges as a result of many years of mineral deposition. At intervals of about twenty minutes, the pools will beat like a drum, with the water surface visibly vibrating and accompanied by a audible thumping noise and ground vibration surrounding the pools, as a result of collapsing steam bubbles far below. | Steam rises from the many geysers, springs and pools on Geyser Hill near Old Faithful, just after sunrise | Emerald Pool, Black Sand Basin | Grotto Geyser, located in the Upper Geyser Basin, is named for its oddly-shaped sinter cone, possible formed around old tree stumps. Grotto Geyser erupts with intervals of approximately eight hours, and eruptions span from two to more than 24 hours with initial heights of 30-40 feet (10-13m) and sustained heights of 10 feet (3m) or more. Grotto Geyser is a fountain-type geyser, erupting through a pool contained within its sinter cone. Observers have noted two principal eruption modes for Grotto Geyser: short and long. Short mode eruptions are typically associated with, and terminated by, activity at neighboring Rocket Geyser. Long mode eruptions are more often associated with activity at nearby Spa Geyser as well as a sinking water level at Marathon Pool. Indeed, these associations are due to underground connections between these features, along with several other geysers, which together form the Grotto Geyser Group. The Grotto Geyser Group is easily reached on the flat 1.5 mile walk from Old Faithful Inn to Morning Glory Pool. | Old Faithful Geyser erupting, viewed from Geyser Hill with unidentified pool in foreground | Blue Star Spring, located in the Upper Geyser Basin, is a near-boiling pool found on the Geyser Hill walk near Old Faithful. During the winter of 1996/1997, a careless (stupid?) young bison fell into Blue Star Spring, quickly cooking itself and briefly turning the spring into a big boiling basin of bubbling bison bouillabaisse. | Firehole Spring, located on the Firehole Lake Drive in the Lower Geyser Basin, is in almost continuous eruption. It is known as a “perpetual spouter” among geyser watchers. Firehole Spring is named not for the nearby Firehole River or Firehole Lake, but for the flaming color of bubbles as they emerge from the submerged vent and head for the surface of the spring. It is easily reached by car, literally a few steps from the roadside. | New Blue Spring is among the Mammoth Hot Springs Terraces in the northwestern part of Yellowstone National Park. The travertine terraces are deposits of calcium carbonate, formed when limestone underneath the terraces is dissolved by mildly acidic heated groundwater, raised to the surface by the hot springs and solidifies there when it is exposed to air. During periods of high flow, individual terracettes can grow rapidly, as much as 8 inches per year. | Orange Spring Mound, located at Mammoth Hot Springs, was formed by mineral deposition but assumes a shape much different than the nearby travertine terraces, probably due to the slow flow of the springs at the top of the mound. It measures roughly 50 feet (16m) by 20 feet (7m). Thermophilic cyanobacteria – primarily the orange forms which thrive in waters cooler than those in the nearby travertine terraces – responsible for the streaks of color down the sides of the mound. Seasonal variations in temperature cause the mounds colors to vary. Orange Spring Mound's springs have been active since at least 1871 although one of the primary springs ceased flowing in 1924. | Orange Spring Mound, located at Mammoth Hot Springs, was formed by mineral deposition but assumes a shape much different than the nearby travertine terraces, probably due to the slow flow of the springs at the top of the mound. It measures roughly 50 feet (16m) by 20 feet (7m). Thermophilic cyanobacteria – primarily the orange forms which thrive in waters cooler than those in the nearby travertine terraces – responsible for the streaks of color down the sides of the mound. Seasonal variations in temperature cause the mounds colors to vary. Orange Spring Mound's springs have been active since at least 1871 although one of the primary springs ceased flowing in 1924. | Dragon's Mouth hot spring is a hot spring fronted by a pool churned by steam, carbon dioxide and hydrogen sulfide vapors roiling up through the pool formed in the spring's cavernous mouth. Mud Volcano area, Yellowstone National Park. | | Old Faithful Geyser, perhaps the singlemost feature that the public most closely associates with Yellowstone National Park. | Rustic Falls is located at the entrance to Golden Gate Canyon near Mammoth Hot Springs. | Yellowstone's historic 1988 fires destroyed vast expanses of forest. Here scorched, dead stands of lodgepole pine stand testament to these fires, and to the renewal of these forests. Seedling and small lodgepole pines can be seen emerging between the dead trees, growing quickly on the nutrients left behind the fires. Southern Yellowstone National Park. | | The Artist Paint Pots area of Yellowstone National Park holds steaming pools, mud pots (roiling mud mixed with sulfuric acid and steam) and paint pots (mud pots colored with dissolved minerals). | | Elk are common throughout Yellowstone. This elk's antlers are growing rapidly during summer as the mating season approaches. Note the velvet covering the antlers -- the velvet will be shed when the antlers have reached full size. |
