VOLCANIC
SPRINGS

Shoshone Geyser Basin, Little Giant Group

The first thermal features you come across if you enter the basin from the north are belonging to Little Giant Group. On the left side of the trail an exposed, nearly 1 m (3 feet) high sinter cone of the Sulphur Springs welcomes the hiker like a petrified butler.

Sulphur Springs, Shoshone Basin Yellowstone
Sulphur Springs

A short distance farther south the Horse Trail Springs show up next to the trail. One of them, SLGGNN006, the feature closest to the trail, is a weak but frequent spouter.

Horse Trail Springs and Trailside Geyser, Shoshone Basin Yellowstone
Horse Trail Springs SLGGNN006 (far left, erupting) and SLGGNN005 (left) and Trailside Geyser (center)

Horse Trail Springs, Shoshone Basin Yellowstone
Horse Trail Springs

Trailside Geyser, adjoining the Horse Trail Springs to the west, is slightly stronger than SLGGNN006 and erupts up to three times within 30 minutes.

Trailside Geyser, Shoshone Basin Yellowstone
Trailside Geyser

Trailside Geyser's runoff is home of some small vents, which may also erupt from time to time.

Geyser SLGGNN001, Shoshone Basin Yellowstone
The tiny geyser SLGGNN001 (erupting beyond the boulder) in the runoff area of Trailside Geyser

Next notable features along the trail are the two blue pools SLGGNN026 and SLGGNN027.

Hot springs SLGGNN026 and SLGGNN027, Shoshone Basin Yellowstone
SLGGNN026 (front) and SLGGNN027 (rear)

The bank of Shoshone Creek within Little Giant Group is occupied by further geysers. Namesake of the group is Little Giant Geyser. The last minor eruptions up to 6 feet height were reported in 2006, major eruptions ceased already shortly after the 1959 earthquake. The deep, ragged crater on the right (west) side of Little Giant's vent developed step by step since 2009. The washout indicates that forceful spouting activity must have taken place in summer 2013.

Little Giant Geyser, Shoshone Basin Yellowstone
Little Giant Geyser (the deep funnel in center) in 2013, the small crater on the lefthand side is SLGGNN031

On our visit in August 2015 Little Giant Geyser's new vent (possibly a new geyser of its own, as T. Scott Bryan describes it as UNNG-SHO-26) played very regularly at intervals of approximately 30 minutes. The play lasted 10 to 15 minutes. Possibly it is cyclic, but we didn't watch long enough to confirm this.

Little Giant Geyser, Shoshone Basin Yellowstone
Little Giant Geyser / UNNG-SHO-26 in 2015

Neighbor of Little Giant Geyser to the southeast is double-vent spring SLGGNN034, looking like a geyser but not known to erupt. Some feet farther east lies Double Geyser, a frequent spouter.

Double Geyser and SLGGNN034, Shoshone Basin Yellowstone
Double Geyser (left) and SLGGNN034 (just below center)

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