An Unintentional Creation
Fly Geyser is not a natural formation. Its existence is the result of two separate drilling attempts, nearly 50 years apart. The first occurred around 1916 when settlers drilled a well for irrigation water in Nevada's Hualapai Flat. They discovered geothermal water at a temperature of about 200°F (93°C), which was too hot for their crops, and abandoned the well. Over the following decades, dissolved minerals from the gushing water precipitated to form a calcium carbonate cone approximately 10 to 12 feet tall, which became known as "The Wizard."
In 1964, a geothermal energy company drilled a new test well a few hundred feet away. The water they found was still around 200°F, not hot enough for their energy production goals. The company attempted to cap the well, but the seal failed. Pressurized water escaped and created a new geothermal feature. This new spouter, Fly Geyser, diverted pressure from the original 1916 well, largely drying it up. The new, uncapped well has been releasing water continuously ever since, building the geyser we see today.
The Science of Color and Form
The Fly Geyser structure is a complex of multiple cones on a large mound. The main cones are about 6 feet (1.8 m) tall, and the entire formation rises 25 to 30 feet (about 9 m) from the desert floor. Water, heated by a deep pool of hot rock, constantly jets up to 5 feet (1.5 m) into the air.
The structure is composed primarily of travertine, a form of limestone (calcium carbonate) deposited by the mineral-rich water. The water also has a high concentration of silica, which allows quartz to form inside the geyser at an unusually rapid rate. The constant deposition of minerals causes the entire formation to grow by several inches each year. This mineral-laden outflow has created between 30 and 40 terraced pools across 74 acres.
The geyser's colors do not come from the minerals themselves. Instead, they are the product of thermophilic algae and cyanobacteria. These microorganisms are adapted to thrive in the hot, moist environment. Different species prefer different temperatures, creating distinct zones of color—reds, greens, and oranges—across the travertine surfaces.