Livingston, MT- AUGUST 19:Fly fishers remove their boat from the Yellowstone River  near Livingston, MT on August 19, 2016. Montana Fish, Wildlife, and Parks has closed 183 miles of the Yellowstone River  to all recreation due to a fish die off caused by a parasite, proliferative kidney disease, that has killed thousands of whitefish and has the potential to kill the Yellowstone's world famous trout fishery.  Low river flow and high river temperatures have caused the proliferation of the parasite. (Photo by William Campbell-Corbis/Getty Images)