Top visitor questions about Yellowstone's thermal areas (Yellowstone Monthly Update - June 2026)

Summer is here, and millions of people will be visiting Yellowstone National Park. People with questions. What is this scat I’m seeing? How does a geyser erupt? What makes Yellowstone so special?

Where’s the bathroom?

We asked Yellowstone interpretive rangers to tell us the most common questions they hear every summer. Those questions and their answers are part of this month's video update!

Some of the most common questions are about the temperature of the water. Geysers are all boiling, but the temperature of hot springs can vary from lukewarm to almost boiling. Mammoth Hot Springs has no boiling water because the water takes a very long journey from the heat source beneath the caldera. So there are no geysers in Mammoth Hot Springs because there's no boiling water.

Acidity also varies by thermal area. Mud Volcano is more acidic than features found in Upper Geyser Basin. The acidity is not concentrated so it's not enough to burn you; the danger is the water temperature.

There are also a lot of questions specific to geyser basins. At Mammoth Hot Springs, many visitors ask about the amazing terraces. This is a mineral called travertine, which forms as the hot water rises to the surface and then loses the carbon dioxide that's dissolved in the water, which triggers the precipitation of the travertine.

At Old Faithful, common questions relate to how geyser predictions are made. These predictions are based on the statistics of preceding eruptions - how intense or long they were.

In Norris Geyser Basin, visitors often ask about the blue color of some of the hot springs. That's caused by silica dissolved in the water. And where is Norris Geyser? There actually is no such geyser. The basin itself is named for the second superintendent of Yellowstone National Park, and it encompasses a huge area that actually encloses four subbasins.

Finally, how does the Park Service know where to put the boardwalks? That's a collaborative effort between geologists and engineers looking for cool ground based on thermal and ground cover data.

There you have it – the top questions asked of Park interpreters every summer. Enjoy your trip!

During the month of May 2026, the University of Utah Seismograph Stations, which monitors and operates the Yellowstone seismic network, located 45 earthquakes. The largest was a Magnitude 2.0. There has been no significant uplift or subsidence of the caldera since January 2026. Echinus Geyser had two water eruptions, on May 6 and 26. Black Diamond Pool had two events, on May 5 and 11. Yellowstone volcano remains at normal, background levels of activity.

For questions, email yvowebteam@usgs.gov

Read Caldera Chronicles https://www.usgs.gov/volcanoes/yellowstone/caldera-chronicles

Visit Yellowstone Volcano Observatory website https://www.usgs.gov/volcanoes/yellowstone