(BILLINGS, MT) – A disease known to decimate wildlife populations in the Yellowstone area has been found in a Montana cattle herd. Federal livestock officials confirmed Thursday that a case of brucellosis has been found in Madison County, Montana. The county borders Fremont County, Idaho to the north. Yellowstone bison and elk are the most common carriers of the disease, which Montana authorities have worked hard to eradicate. The infected cow was tested only a year ago and was clean at that time. They believe this is an isolated incident, and has not impacted other livestock in the region.