One of countless small holes in the thin layer of earth covering underground hot springs in Yellowstone.
The water is boiling temperature. The ground above this boiling water is thin. This is why is it is important to be extremely careful about where one walks in a Yellowstone thermal area.

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Any and/or all usage or copying of this image, without express written permission from the photographer, is prohibited by law. Copyright 2006, Elizabeth Bickel. All Rights Reserved