File:Lakeshore Geyser (29 August 2011) 01.jpg

English: Geysers are hot springs that episodically erupt columns of water. They occur in few places on Earth. The highest concentration of geysers anywhere is at the Yellowstone Hotspot Volcano (northwestern Wyoming, USA).

Lakeshore Geyser is located in the Lower Group of Yellowstone's West Thumb Geyser Basin - it can be closely observed from the modern tourist boardwalk. During part of the spring and much of the summertime, this feature is submerged by Lake Yellowstone (see elsewhere in this photo album). The cold lake water prevents the geyser from erupting. At other times, the lake's water level is often low enough to permit eruptions, but it is often dormant anyway.

Lakeshore Geyser consists of two main vents atop a low geyserite mound that is approximately 6 to 7 meters by 4 meters in size. The smaller eastern vent is subcircular and about 0.5 to 0.75 meters in diameter. The larger western vent has a rounded subquadrate shape and is about 1 x 1.4 meters in size. Moderately tall major eruptions from the eastern vent were reported in the early 1900s. The most recent reported major eruption was in 1970.

Observed activity from the western vent on 1 August 2016 ranged from frequent periods of relative calm to light roiling-boiling-spitting to very low to moderately low erupting. The eastern vent usually had energetic events every 4 to 6 minutes. Many resulted in minor eruptions that reached about half-a-meter high. Some events involved overflow and no eruption.

A temperature of 92 degrees Celsius and a pH of 7.3 were measured at Lakeshore Geyser in 2001. Thermal imaging on 1 August 2016 showed a temperature of 95 degrees Celsius in the western vent.