Beauty Pool shows its brightest colors when its water is hottest and is closely related to neighboring Chromatic Pool. During periodic energy shifts, the level of one spring rises as the other lowers. These pools were initially named due to their clear, hot, bright waters. In years since, most noticeably since 2002, the pools have cooled dramatically and colors have changed. Beauty Pool still quietly steams, but the shallow outer parts of the pool are filled with orange thermophiles that can thrive in the cooler waters.

Beauty Pool has an average temperate of 135.6°F (57.5°C), an average pH of 8.8, and an average conductivity of 2042 uS/cm.

Hot Springs

Hot springs are the most common hydrothermal features in Yellowstone. Their plumbing has no constrictions.

Superheated water cools as it reaches the surface, sinks, and is replaced by hotter water from below.

This circulation prevents water from reaching the temperature needed to set off an eruption.

Upper Geyser Basin

The majority of world’s active geysers are in the Upper Geyser Basin, including Old Faithful. Only four other places in the world have large concentrations of hydrothermal features: Russia (Kamchatka), Chile, New Zealand, and Iceland.

The heat for the hydrothermal features comes from Yellowstone’s volcano. Molten rock or magma may be as close as 3-8 miles (5-13 km) underground. Rain and snow supply water that seeps down several thousand feet (more than a kilometer) below the surface where it is heated.

Underground cracks form a natural plumbing system. Hot water rises through the plumbing to produce hot springs and geysers.

Use Caution in Hydrothermal Areas

• Stay on boardwalks and designated trails.
• Hydrothermal water can severely burn you.
• Never run, push, or shove.
• Supervise children at all times.
• Do not scratch hydrothermal mats.

You are responsible for your safety.

Think safety, act safely. Yellowstone is a dangerous place.