Seismograph Pool
Seismograph Pool in Yellowstone N.P.
Seismograph Pool Close-up
Seismograph is Blue in Color
Bubbles in the Pool
Photo Credit: VacationIdea

Seismograph and Bluebell Pools are located at the West Thumb Geyser Basin in Yellowstone National Park. The two pools are blue in color. The Seismograph pool occasionally collects mud from nearby mudpots.

Seismograph and Bluebell Pools can be viewed from the outer loop of the West Thumb Geyser Basin Trail. A steep grade connects the outer loop boardwalk with the inner loop. The two pools are located next to that grade. The bright blue color is due to extremely high temperatures, usually around 165 degrees F.

Nearby hydrothermal features include the Black Pool, Fishing Cone and the Abyss Pool. Read more about West Thumb Geyser Basin.