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

Added: 2026-06-02

[00:00:00]Summer is here, and with it, millions of people will be coming [music] to Yellowstone National Park. Most of those people will spend time in an iconic thermal area [music] like Mud Volcano or Norris Geyser Basin, and those people will have questions. We've asked Yellowstone interpretive rangers, "What are the top questions you're asked every [music] summer?" The number one question, you might even say the number one and the number two question, "Where is the bathroom?"

[00:00:23]Some of the most common questions are about the temperature and acidity of the water. Now, geysers are all boiling, but hot springs can vary from lukewarm to almost boiling, and it varies by geyser basin. A place like Norris is the hottest geyser basin in the park, but Mammoth Hot Springs has no boiling [music] water at all because the water has to take a very long journey from the center of the park to get up to the northern reaches. So, there are no geysers in Mammoth Hot Springs because there's no boiling water. Acidity also varies by thermal area. Mud Volcano, which is dominated by steam, is a more acidic environment than say Upper Geyser Basin, which is dominated by neutral waters. The acidity is not concentrated, though, so it's not enough [music] to burn you. The danger is really the water temperature.

[00:01:02]There's also a lot of questions that are specific to geyser basins. At Mammoth Hot Springs, the question is, "How do these amazing terraces [music] form?"

[00:01:09]This is a mineral called travertine, which forms as the hot water rises to the surface >> [music] >> and then loses the CO2, the carbon dioxide that's dissolved in the water, and that triggers the precipitation of the travertine into these gorgeous terraces. At Old Faithful, common questions relate to how geyser predictions [music] are made. This is really based on the statistics of preceding eruptions. For example, how intense or long [music] they were. Here in Norris Geyser Basin, visitors often ask about the blue color of some of the hot springs. That's caused by silica that's dissolved in the [music] water.

[00:01:39]And where is Norris Geyser? There actually is no such geyser. The basin itself is named for the second superintendent of Yellowstone National [music] Park, and it encompasses a huge area that actually encloses four sub-basins. Finally, a really good question, "How does the Park Service know where to put these boardwalks?"

[00:01:56]Well, that's a collaborative effort between geologists and engineers looking for cool ground based on thermal imagery or temperature measurements where these boardwalks can safely go.

[00:02:05]There you have it. Top interpreter [music] questions asked every summer here in Yellowstone National Park. Now, let's talk about the seismic activity, ground deformation, [music] and hydrothermal activity that occurred over the past month.

[00:02:16]>> Earthquake activity in the Yellowstone region remains at very low levels. The University of Utah seismograph stations located just 45 earthquakes during the month of May. They were spread throughout the region, no swarms, and the largest event was a magnitude 2.0 on the east side of the park. Turning now to ground deformation, this is vertical deformation at the Lake GPS site. That's on the east side of the caldera.

[00:02:39]This plot spans 2 years. Each one of these blue dots is 1 day of data.

[00:02:43]Downward trends are subsidence and upward trends indicate uplift. Since 2015, there's been overall subsidence of this particular [music] site in the caldera in general. It's interrupted in the summer months by a small amount of uplift due to groundwater recharge from spring runoff. But, since December or so of 2025, there has been no net deformation of the caldera. And since January 2026, there's been no net deformation on the north caldera rim.

[00:03:09]So, over the last several months, really no deformation to speak of in the Yellowstone region.

[00:03:14]Finally, now looking at geyser activity, no eruptions of Steamboat geyser, but there were two eruptions of nearby Echinus geyser in Norris Geyser Basin.

[00:03:23]This is the temperature in the runoff channel for Echinus geyser. These small spikes that occur sort of throughout the month are small overflows of the geyser, and then the eruptions occurred here on May 26th and earlier in the month on May 6th. There were also three eruptions of Black Diamond Pool in Biscuit Basin, relatively minor eruptions. This was the site of the major hydrothermal explosion back in 2024. So, Black Diamond also remains active. [music] Well, that does it for the monthly update of the Yellowstone Volcano Observatory. If you have any questions, feel free to leave us a comment or drop us a line. Our email address is YVOwebteam, [music] all one word, at usgs.gov.

[00:04:00]We'll be back next month, so until then, stay safe and stay healthy.

[00:04:03]Bye-bye.

[00:04:08]>> [music]