Click on an image to see a larger version.
This spectacular fumarole area at Mount Lassen National Park is easily explored on a series of boardwalks.
Bumpass Hell, Lassen Volcanic NP, CA (1985).
A small but genuine geyser among the hot mineralized springs at the head of the Napa Valley.
Old Faithful Geyser, Calistoga, CA (1984).
The hot mineral springs at Calistoga have been utilized for therapeutic bathing (and mudbaths) for over a century.
Calistoga, CA (1989).
The extensive geothermal activity at Yellowstone is constantly showing up in new areas, including parking lots.
Biscuit Basin, Yellowstone NP, WY (1977).