The U.S. Department of Interior just canceled grazing leases for hundreds of bison on federal land in Montana. The action halts the progress of a well-funded private group, American Prairie, that has been buying up land and acquiring leases in an ambitious conservation plan. The group often provides bison to tribes that work to revive bison herds. The canceled leases also indicate a change in federal policy away from accommodating bison in favor of domesticated cattle to make federal lands more agriculturally productive. Many tribes say such actions jeopardize efforts to restore the animal that is intrinsically associated with Native Americans from the Great Plains.