"We spent months of computation time doing the imaging with our new techniques," Thorne said.

Why does the ice exist?

Rock glaciers differ from conventional glaciers because their ice sits hidden under a cover of loose rock. In Utah's Wasatch and Uinta ranges, these formations are widespread. Similar features appear on the Colorado Plateau in the La Sal Mountains near Moab.

Researchers propose that the mountains themselves create the ice. Falling rock debris covers persistent snow in upper sections of the glaciers, shielding it from sun and warm air. Over thousands of years, repeated rockfalls build up debris layers that preserve the snowpack beneath.

"In the Wasatch, the mountains themselves are eroding and burying the snow, and that's why the rock glaciers exist," said Leif Anderson, a glaciology professor who co-led the studies.

The team's mathematical model suggests Utah's rock glaciers formed long after the Ice Age, which peaked 21,000 to 18,000 years ago. They developed during the thousands of years after large ice-age glaciers disappeared from the region.

How much water could Utah's rock glaciers hold?

Satellite imagery has identified 836 rock glaciers across Utah. Using the area-to-volume relationship established at Timpanogos, the researchers estimate these features may collectively hold about 1 gigaton of water, roughly 815,000 acre-feet. One acre-foot covers one acre of land under one foot of water, about 1,233 cubic meters.

"There's a lot of ice that's hidden in Utah's mountains," Anderson said. "When we are high in the mountains and walking across loose rocks or rubble, you don't realize there could be 120 feet of ice buried beneath your feet."

The estimate carries uncertainty. Rock glaciers in different climates may have very different ice-to-rock ratios. Direct measurements exist for only a handful of sites worldwide.

Could similar ice stores exist elsewhere?

Approximately 50,000 rock glaciers have been cataloged globally. Applying the Utah scaling relationship, the team estimates they may collectively contain about 48 gigatons of water. One gigaton equals one cubic kilometer, enough to fill 400,000 Olympic swimming pools.

The global estimate is preliminary, the researchers caution. The 83% ice fraction measured at Timpanogos may not apply to drier or warmer regions.

Where can I read the studies?

The first paper, "Mass Addition to Timpanogos Rock Glacier: Debris-Covered Snow and the Importance of Interannual Variability in Headwall Erosion and Climate," appeared in Geophysical Research Letters on April 2, 2026. Stanford undergraduate Isaiah Davies led that work during a 2023 summer at the University of Utah.

The second paper, "The Internal Ice Content of Timpanogos Rock Glacier, Utah, USA From 3-D Bayesian Inversion of Gravity Data," was published in the Journal of Geophysical Research on August 26, 2026. Funding came from the U.S. Geological Survey, the National Science Foundation, the University of Utah's Wilkes Center for Climate Science & Policy, and other university programs.