Turquoise Pool, Hot spring in Midway Geyser Basin, Yellowstone National Park, Wyoming, US.

Turquoise Pool is a hot spring in the Midway Geyser Basin of Yellowstone National Park, Wyoming, with water between 142 and 160 °F (61 and 71 °C). It sits among the basin's other thermal features, and its name was given by members of the Hayden Expedition of 1878.

Members of the Hayden Geological Survey named and documented this feature during their 1878 expedition, which systematically mapped thermal features across Yellowstone. This early scientific work established how the geothermal landscape was understood and studied.

The name comes from the Hayden Expedition of 1878, whose members recorded the pool during their survey of the Midway Geyser Basin. The water measures between 142 and 160 °F (61 and 71 °C), and the pool sits among the basin's other thermal features along the boardwalk circuit.

Access to the pool is via marked boardwalks that keep visitors at a safe distance from the hot water and thermal features. Stay on the designated paths at all times to protect both yourself and the fragile geothermal ecosystem.

The water color shifts throughout the year as temperature changes alter which heat-loving bacteria thrive in the pool. These seasonal color changes offer visitors a chance to observe how living organisms shape the appearance of geothermal features.