This environmental assessment considers the biological, environmental, and socioeconomic effects of a proposal to establish a self-sustaining population of whooping cranes (Grus americana) separate from the two existing populations. This action has been recommended by the Whooping Crane Recovery Team to contribute to the long-term recovery of the endangered whooping crane. Alternatives considered in this environmental assessment include: (1) No Action; (2) establish a nonessential experimental migratory population of whooping cranes in the eastern United States with introduction of cranes to Wisconsin and migration to a wintering site at Chassahowitzka National Wildlife Refuge in Florida (Preferred Alternative); (3) establish a migratory population of whooping cranes, classified as endangered, in the same locations; (4) establish a nonessential experimental migratory population of whooping cranes with initial reintroduction to Seney National Wildlife Refuge in Michigan and migration to a wintering site at Chassahowitzka National Wildlife Refuge in Florida. Regions 2, 3, 4, 5, and 6 of the U. S. Fish and Wildlife Service are cooperating in this endeavor.