Editor's note: Yellowstone Caldera Chronicles is a weekly column written by scientists and collaborators of the Yellowstone Volcano Observatory. This week's contribution is from Michael Poland, geophysicist with the U.S. Geological Survey and Scientist-in-Charge of the Yellowstone Volcano Observatory.
Many of the monitoring sites in Yellowstone National Park are located in remote areas. When they go offline, a lot of preparation and effort is necessary to bring them back to functionality.
The continuous GPS station at White Like, designated WLWY (GPS stations are always given 4-character codes), is one of the most interesting in all of Yellowstone National Park. The station was installed in 1999 on the Sour Creek resurgent dome—one of two uplifted areas of Yellowstone caldera that formed due to magma accumulation shortly after the major caldera-forming eruption about 631,000 years ago (the other is the Mallard Lake dome, near Old Faithful).
The Sour Creek resurgent dome continues to deform to this day, rising and falling by a few centimeters (about an inch) per year. Since 2015 the area has been subsiding (sinking), but prior to that there have been periods of uplift, for example, during 2004–2009. This persistent deformation was the reason that one of the first remote GPS stations in Yellowstone was installed in the White Lake area. The station is located almost 13 kilometers (about 8 miles) to the east of Hayden Valley and roughly 1.5 kilometers (about 1 mile) southwest of White Lake at the top of a hill. The site provides great sky view, which is critical for GPS, because there are only a few trees in the area. The backcountry location is far from any roads or trails, so the only way to realistically reach the site is by helicopter.
In summer 2024, the WLWY station malfunctioned. The GPS receiver that logs the data was still reachable by the radio link, but the antenna was not seeing any satellites and no data were being collected. Something was clearly wrong, but was it the antenna? Or the cable that connects the antenna to the receiver? Or perhaps something with the receiver hardware? There are a lot of things that can go wrong at remote monitoring stations, and maintaining the sites is a big job.
Owing to fire responses and search and rescue operations that occupied the park’s helicopter, it was not possible to visit the site in 2024. So engineers from the EarthScope Consortium, which operates GPS stations throughout the USA and beyond, planned a trip for summer 2025—a trip that finally happened on September 17 thanks to support from the Yellowstone National Park helitack crew.
The engineers loaded the helicopter with all of the tools and equipment they would need to diagnose and repair any problem that might be present at the station, as well as additional gear to perform some helpful upgrades. Upon arrival, the problem quickly became clear—water had accumulated around a connection in the antenna cable, causing corrosion. The engineers replaced the cable, restoring connectivity between the receiver and the antenna. The major problem was solved!
The engineers also moved the GPS receiver to a new location, close to the hub of solar and battery power, and added a new battery to the power system. Then, they replaced the radio link, which had connected the site to a radio hub at Mount Washburn several miles to the north, with a cellular modem. The new modem is much faster and allows data to be collected at high rates and even downloaded in real time, if needed—something that wasn’t possible using the older radio connection. Finally, the engineers added meteorological sensors that log temperature, barometric pressure, and other conditions—useful information when trying to understand how apparent motion of the GPS station might be related to changing weather.
The improvements at WLWY should ensure that the site continues to provide high-quality ground deformation data from the Sour Creek resurgent dome for many years to come. Thanks to EarthScope engineers Brendan Hodge and Lia Lajoie for their excellent work!
For a video documenting the repair work, check out the Yellowstone Volcano Observatory October 2025 monthly update (https://www.youtube.com/
Stories about:
Story Categories:
A copy of National Parks Traveler's financial statements may be obtained by sending a stamped, self-addressed envelope to: National Parks Traveler, P.O. Box 980452, Park City, Utah 84098. National Parks Traveler was formed in the state of Utah for the purpose of informing and educating about national parks and protected areas.
Residents of the following states may obtain a copy of our financial and additional information as stated below:
- Florida: A COPY OF THE OFFICIAL REGISTRATION AND FINANCIAL INFORMATION FOR NATIONAL PARKS TRAVELER, (REGISTRATION NO. CH 51659), MAY BE OBTAINED FROM THE DIVISION OF CONSUMER SERVICES BY CALLING 800-435-7352 OR VISITING THEIR WEBSITE. REGISTRATION DOES NOT IMPLY ENDORSEMENT, APPROVAL, OR RECOMMENDATION BY THE STATE.
- Georgia: A full and fair description of the programs and financial statement summary of National Parks Traveler is available upon request at the office and phone number indicated above.
- Maryland: Documents and information submitted under the Maryland Solicitations Act are also available, for the cost of postage and copies, from the Secretary of State, State House, Annapolis, MD 21401 (410-974-5534).
- North Carolina: Financial information about this organization and a copy of its license are available from the State Solicitation Licensing Branch at 888-830-4989 or 919-807-2214. The license is not an endorsement by the State.
- Pennsylvania: The official registration and financial information of National Parks Traveler may be obtained from the Pennsylvania Department of State by calling 800-732-0999. Registration does not imply endorsement.
- Virginia: Financial statements are available from the Virginia Department of Agriculture and Consumer Services, 102 Governor Street, Richmond, Virginia 23219.
- Washington: National Parks Traveler is registered with Washington State’s Charities Program as required by law and additional information is available by calling 800-332-4483 or visiting www.sos.wa.gov/charities, or on file at Charities Division, Office of the Secretary of State, State of Washington, Olympia, WA 98504.
INN Member
The easiest way to explore RV-friendly National Park campgrounds.
Here’s the definitive guide to National Park System campgrounds where RVers can park their rigs.
Our app is packed with RVing- specific details on more than 250 campgrounds in more than 70 national parks.
You’ll also find stories about RVing in the parks, tips helpful if you’ve just recently become an RVer, and useful planning suggestions.
