Fly Geyser

Fly Geyser is a small, colourful geyser in Washoe County, Nevada, about 32 kilometres north of the town of Gerlach, near the Black Rock Desert. It is roughly 1.5 metres high and 3.7 metres wide, counting the mound it sits on, though other parts of the mound are taller.

It is not completely natural. It formed after people drilled wells looking for water, and the minerals in the hot water slowly built coloured cones around the opening. The geyser stands on private land that is now owned by a non-profit group. Only limited public access has been allowed since 2018.

How did it form?

The first geyser here appeared in 1916 when a well was drilled for irrigation water. The water was almost boiling, so the well was abandoned, and a calcium carbonate cone about 3 metres high grew around it.

In 1964 a geothermal energy company drilled a second well nearby. The water was not hot enough to make electricity. The company capped it, but the seal failed, and the new geyser took over from the old one. Minerals such as calcium carbonate and silica have piled up ever since.

Why the colours?

Heat-loving microbes called thermophilic bacteria and archaea thrive in the hot, wet mounds, colouring the rocks in greens and reds.

The water can exceed 93 degrees Celsius. A scientist who studied it reported a very high amount of silica, which has formed quartz inside it unusually fast. The Burning Man Project bought Fly Ranch in 2016, and offered limited public access from 2018.

On the globe

Find it on the globe in northwestern Nevada and zoom in to open its card.