Oases in Navajo desert contained 'a witch's brew'

Cameron, Ariz. -- In all her years of tending sheep in the western reaches of the Navajo range, Lois Neztsosie had never seen anything so odd.

New lakes had appeared as if by magic in the arid scrublands. Instead of hunting for puddles in the sandstone, she could lead her 100 animals to drink their fill. She would quench her own thirst as well, parting the film on the water's surface with her hands and leaning down to swallow.

Despite the abundant water, an unexpected blessing, her flock failed to thrive. The birthrate dropped, and the few new lambs that did appear had a hard time walking. Some were born without eyes.