Upper Geyser Basin, Cascade Group and Westside Group
On the way from Morning Glory Pool to Biscuit Basin you hike through the Cascade Group. The first and most important geyser along the trail is Artemisia Geyser. It got its name from the appearance of the widespread geyserite lining, whose color resembles the grayish-green of the sagebrush Artemisia tridentata. Artemisia's interval ranges between 9 and 34 hours. Eruptions last up to half an hour and reach 9 m (30 feet) height in maximum.
Beyond Artemisia the two small cones of Atomizer Geyser can be spotted. Its play is quite complex. Some hours after an overflow three to five minor eruptions occur about one hour apart, reaching up to 9 m (30 feet) height. 15 min to one hour after the last minor, the major eruption starts from the west cone, jetting a fine spray of water through a narrow aperture up to 15 m (50 feet) and lasting approximately 10 minutes. Meanwhile the smaller east cone does only release steam, but it starts emitting even finer spray than its neighbor when the west cone enters a steam phase near the end. The interval between major eruptions is typically near 15 hours.
With a little luck one may catch Artemisia Geyser and Atomizer Geyser in concerted eruption.
Upslope of Artemisia Geyser the trail gives access to the rusty orange Iron Spring and its quite similar neighbor. (Update 2017: the path to Iron Spring has been closed to public access)
150 m (165 yards) farther north the next cluster of springs around Gem Pool appears. Gem Pool itself is a deep blue, gorgeous spring, which is very well named.
The quiet Pinto Spring in direct vicinity discharges into Gem Pool.
Sprite Pool, a few feet to the north, is an intermittent spring, showing weak splashing occasionally.
Farther north the quiet Blue Femur Spring marks the junction between Cascade Group and Old Road Group.
The Continental Divide Trail between Daisy Group and Biscuit Basin provides the closest approach to those features of Cascade Group that line Firehole River and also to thermal features across the river, which are belonging to Westside Group. Here the meaning of "close" is relative because the trail always keeps a quite large distance to the features while the thermal groups themselves are closed to public access. So observation possibilities are limited to the rims of some springs you can spot from the shoulder of the trail and to eruption columns of geysers in this area, if you are lucky enough to witness an eruption.
The only feature next to the trail is the unnamed blue-green pool UWGNN009.
Across Firehole River an extended steam plume indicates the position of Seismic Geyser on top of the slope. It was created by the Hebgen Lake earthquake in 1959 and played up to 23 m (75 feet) high up until 1971, when a satellite vent opend up and the eruptions declined and finally ceased in the 1980s. Now Satellite Geyser owns the much larger pool in center, Seismic Geyser is located on its southeast side (on the picture on its right) and on the northeast side the pool of Aftershock Geyser adjoins. Latter developed its vent in summer 1997 and became apparent by eruptions from May 1999 onwards.
One of the most interesting geysers of the Westside Group, Fantail Geyser, lies down the slope a few feet above the water level of Firehole River and is hard to spot. If it would be accessible, the terraced arrangement of blue pools, each surrounded by delicate, beaded sinter rims, would make a great photo motif. The picture below, taken with a long telephoto lens, does no justice to the beautiful setting. In this case a view from above, for example by using Google Maps, gives a better impression of the arrangement. Fantail Geyser had major eruptions from two vents up to a height of 23 m (75 feet) during the 1980s.
A short way downstream on the east bank of Firehole River the bulged vent of Broken Cone Geyser can be seen. It plays only a few feet high at irregular intervals.
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