A helicopter flying over the Great Salt Lake last winter was looking for something that should have been hard to find: fresh water hiding under one of the saltiest places in the American West. What turned up was a sharper picture of an underground system that may be far larger than scientists once thought. Using airborne electromagnetic surveys over Farmington Bay and part of Antelope Island, University of Utah researchers found signs that freshwater-saturated sediments lie beneath the lake’s hypersaline surface and may extend down 3 to 4 kilometers, or roughly 10,000 to 13,000 feet. That does not mean a giant new water supply is ready to be tapped. But it does suggest the eastern margin of the Great Salt Lake holds a deep and surprisingly extensive freshwater zone beneath a thin saline layer, a finding that could matter for dust control, water planning, and future lake-wide surveys. The work appears in Scientific Reports and is part of a broader state-funded effort led by the University of Utah’s Department of Geology & Geophysics to understand …