Emerald Pool is a large steaming pool with thin, solidified sinter around the edge of the pool. Orange thermophiles line the bottom of the pool and throughout the outwash channel. Emerald Pool was once blue with some yellow thermophiles that caused its waters to appear green, hence its name. But like other pools in Black Sand Basin, a drop in water temperatures have resulted in the loss of the bright pools, with them being replaced with orange, murky pools.

Emerald Pool has an average temperate of 136.3°F (58°C), an average pH of 9, and an average conductivity of 2216 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.

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.