Place

Stop 4: Footbath Spring

Remnants of a wooden structure near a volcanic mudpot.
Footbath Spring

NPS

This spring is quite acidic with a pH value of between 1.7 and 3. For comparison, lemon juice has a pH of 2.2, and battery acid has a pH of 1. The temperature of this spring has been measured at about 75 degrees F and at 103 degrees F only a few weeks apart. Water properties in this spring change frequently! We don’t know for sure why, but we could hypothesize that the changes may be due to what is happening weatherwise. Has there been a lot of rain or snow contributing cool water with a neutral pH to the hot acidic water from deep underground?

Footbath Spring can be dry when it hasn’t rained for a while. But you can always hear the gas escaping if you listen quietly from a distance.

Valles Caldera National Preserve

Last updated: December 12, 2024