Sapphire Pool

Photographer Frank Jay Haynes named the Sapphire Pool at Yellowstone National Park for its blue color. The pool historically had small occasional eruptions, but a 1959 earthquake transformed it into a geyser and muddied its waters. Additionally, the small “biscuits” shown on the edges of the pool were destroyed by the larger eruptions. The geyser last erupted in 1971, and the waters have since cleared.

Image: “Sapphire Pool, Yellowstone National Park” by the Detroit Photographic Company (1902). From Denver Public Library Special Collections