The National Park Service and U.S. Forest Service have confirmed plague as the cause of a prairie dog die off in Badlands National Park, Buffalo Gap National Grassland, and the greater Conata-Badlands ecosystem, in South Dakota based on a test result received 5/31.

The risk to humans remains low, however, plague is concerning. The disease has not been detected in Conata Basin since 2009, when it was responsible for killing more than 80 percent of the remaining population black-footed ferrets, one of the most endangered mammals in the world.