Sponge Geyser is located on Geyser Hill in the Upper Geyser Basin of Yellowstone. Sponge was active in October 1998 but it is not very impressive. Sponge has an interval of few minutes. The pool rises and falls with some splashing on the edge nearest the boardwalk.
Sponge Geyser:
All images copyright 1998, Michael Frazier. All rights reserved.