The water levels at the Great Salt Lake have hit a historic low, a grim milestone for the largest natural lake west of the Mississippi River that comes as a megadrought grips the region.

On Saturday, the US Geological Survey announced average daily water levels had dropped about an inch below the previous record of 4,191.4ft (1,278 meters) above sea level, which was set in 1963.

The new record comes months earlier than when the lake typically hits its lowest level of the year, indicating water levels could continue to drop even further, said Candice Hasenyager, the deputy director of Utah’s division of water resources.

Receding waters are already affecting a nesting spot for pelicans, which are among the millions of birds dependent on the lake. Sailboats have been hoisted out of the water to keep them from getting stuck in the mud. As more dry lakebed is exposed, arsenic-laced dust blows into the air that millions breathe.

People for years have been diverting water from rivers that flow into the lake to water crops and supply homes. Because the lake […]