A frothy, green layer of muck recently coated a miles-long stretch of water on the Lower Snake River in southeast Washington, and scientists have warned people and their pets to stay away.

The Whitman County Health Department issued an alert on Oct. 6 that a blue-green algal bloom released toxins into the water between Wawawai Landing and Central Ferry State Park, making a roughly 30-mile stretch of the river temporarily hazardous for humans, pets, and livestock.

LINK (via The Spokesman-Review)