File:Twin Geysers.jpg

English: Twin Geysers, western Lower Group, West Thumb Geyser Basin, Yellowstone Hotspot, northwestern Wyoming, USA in August 2011 (looking ~SE).

Twin Geysers consists of the two water-filled vents shown above, surrounded by a low, irregularly-mounded geyserite that is partially stained reddish-brown and yellowish by iron oxides. Geyser eruptions here have been rare in recent decades, and occurred sporadically before then, including the 1910s, the 1930s, the late 1940s, the early 1950s, and the early to mid-1970s. The highest reported Twin Geysers eruption was about 200 feet high in 1910. Another significant eruption was about 120 feet high in 1934. Twin Geysers was most active from 1971 to 1973, with maximum water column heights of about 120 feet. During eruptions, water would spout from both vents, but essentially converge in the air.

Twin Geysers also erupted on two days in 1998 and 1999.