In the late 1980s, U.S. park rangers began finding bear carcasses missing only gallbladders and paws. Initially, it was considered that occasional hunters were the cause, but investigations uncovered evidence that large commercial organizations were dealing in poaching and smuggling. During a three-year operation (Operation SOUP) ending in 1999, 52 people were arrested and 300 gallbladders seized in Virginia. Another investigation in Oregon led police to bring racketeering charges against an organisation that poached an estimated 50 to 100 bears per year for a decade. It was estimated in 2008 that in North America, 40,000 American black bears are illegally poached for their gallbladders and paws each year.