David Boston Photography

The Excelsior Geyser pool discharges 4,000 to 4,500 gallons of 199 °F water per minute directly into the Firehole River (Yellowstone NP).
Canon EOS 5D Mark II, EF24-105mm f/4L IS USM, 24 mm, ISO 100, 1/10 sec at f / 22, © 2014, David W. Boston