Black Sand Basin

Black Sand Basin is where some of the most thermal scenery in the Park exists. The name was derived from black volcanic glass (obsidian) from eruptions. Other features in this area include Black Sand Pool, Iron Creek, Opalescent Pool, Spouter Geyser, Cliff Geyser, Green Spring, Rainbow Pool, and Emerald Pool.

Cliff Geyser is located on the edge of Iron Spring Creek and is an unpredictable geyser. It frequently erupts 25 - 33 feet in varying durations from 10 minutes to 2 - 3 hours.