In 2010, Idaho released fluorescent dye into a well near Malad Gorge to map hidden groundwater routes; later tests traced it through domestic wells up to 3.1 miles away

In 2010, scientists poured fluorescent green dye into a domestic well in southern Idaho and tracked its underground movement. The experiment near Malad Gorge State Park showed that groundwater could move through the fractured volcanic rock of the Eastern Snake Plain Aquifer at speeds approaching 2,000 feet a day, giving researchers a rare glimpse into pathways that normally remain hidden beneath the surface.According to a report by the Idaho Department of Water Resources, the 2010 tracer test was carried out in cooperation with Idaho Power to investigate groundwater movement near Malad Gorge State Park. Researchers released fluorescein dye into the Hopper domestic well, located about 5,490 feet southeast of the gorge, and monitored springs along the river edge and selected domestic wells for traces of the dye. The experiment used a two-phase approach, first identifying the direction and distribution of groundwater movement and then measuring travel time.