Yellowstone National Park is the last area in the U.S. which features free-roaming bison. Each year, however, an average of 250 Yellowstone Bison are slaughtered by the Interior Department when those animals cross an invisible line into the plains in search of food during the winter. In an effort to protect the Yellowstone bison, Congressman Rahall (D-WV) offered an amendment to the 2004 Interior appropriations bill which would have barred the Interior Department from killing bison (ironically, the mascot of the Interior Department's is a bison). Progressives argued that a major goal of the Interior department is the protection of species, not their destruction, and they voted in support of Rahall's amendment to prevent the further slaughter of bison. Despite support from Progressives, the Rahall amendment was defeated 199-220.