Silencing the Thunder

When temperatures drop in Montana, wild bison migrate to lower elevations outside the boundaries of Yellowstone National Park. But once outside, they run the risk of being killed because some carry a chronic disease called brucellosis that ranchers fear could spread to cattle. When temperatures drop in Montana, wild bison migrate to lower elevations outside the boundaries of Yellowstone National Park. But once outside, they run the risk of being killed because some carry a chronic disease called brucellosis that ranchers fear could spread to cattle. When temperatures drop in Montana, wild bison migrate to lower elevations outside the boundaries of Yellowstone National Park. But once outside, they run the risk of being killed because some carry a chronic disease called brucellosis that ranchers fear could spread to cattle. When temperatures drop in Montana, wild bison migrate to lower elevations outside the boundaries of Yellowstone National Park. But once outside, they run the risk of being killed because some carry a chronic disease called brucellosis that ranchers fear could spread to cattle.