The devastating fungal disease that has already killed nearly seven million bats has struck Cumberland Gap National Historical Park in Kentucky. Since a caver first documented white-nose syndrome in a cave in upstate New York in 2006, the epidemic has spread to a total of 19 states and at least four Canadian provinces.

“The arrival of white-nose syndrome in yet another national park is the latest chapter in this tragedy, which is threatening the very existence of several bat species,” said Mollie Matteson, a bat advocate at the Center for Biological Diversity. “This is the 10th national park in the United States now at risk of losing its bats — and all the services they provide to the places where they live.”

The bat disease, named for the white fuzz often found on the muzzles of sick bats, has been documented as far north as Ontario, as far south as Alabama and as far west as Missouri. Last week a bat suspected of having white-nose syndrome was found for the first time on Prince Edward Island, Canada. Park Service officials in Great Smoky Mountains National Park suspect that white-nose syndrome has struck hibernating bat populations in that park, as well. Bats at Great Smoky have been flying outside their hibernating sites this winter, a tell-tale symptom of the disease.

Biologists believe bats are a vector for the disease, but strong evidence also points to humans as a vector, particularly over long distances beyond the typical dispersal distance of bats; there is compelling evidence that people accidentally imported the disease from Europe. Cumberland Gap Park closed most of its caves to human access several years ago, to reduce the risk of spread by people, but Gap Cave remains open for tours.

The Center has been a strong proponent of measures to protect bats from the disease, including restricting nonessential human access to federal caves and mandating decontamination of gear if cave entry does occur. Diminished visitation reduces the risk of fungal spread and lessens disturbance of disease-stressed bats. No cure exists yet for the disease, which may eventually threaten roughly two dozen bat species.

In 2011 scientists estimated that the value of bats’ pest-control services to American farmers was $23 billion per year. Without bats, farmers may be forced to turn to chemical insecticides to keep insect pests at bay. Bats also eat insects that are pests on trees, and through their sheer numbers provide a crucial food source, with their droppings and their bodies, to other cave-dwelling species. Scientists worry that some of the rare and unusual cave organisms that depend on bats for their survival will also be at risk if bats disappear from large swaths of North America.

The Center for Biological Diversity is a national, nonprofit conservation organization with more than 450,000 members and online activists dedicated to the protection of endangered species and wild places.