The Arctic National Wildlife Refuge is one of the last great wilderness areas in the USA, but oil-company officials and Alaskan politicians are pushing hard to open up this 1.5-million-acre refuge to oil and gas drilling. For visitors the main attraction here is the profuse wildlife; the sheer numbers have been compared to those of the Serengeti Plains in East Africa. The park is home to wolves, polar bears, grizzlies, muskoxen, Dall sheep, the vast herd of Porcupine caribou and thousands of migratory birds. It's also the habitat of the world's northernmost population of black bears, which makes it the only place where all three North American bear species are present. The landscape stretches from lagoons, beaches and salt marshes to coastal plain, alpine tundra, and the tall spruce, birch, and aspen of the boreal forest.