A quest for oil sparks a tribal sovereignty fight in Alaska

, the shallow ponds and spruce forests of the Yukon Flats, in Interior Alaska, stir with the flapping of scoters and scaups, the laugh-like yelps of white-fronted geese and the high-pitched whistle of wigeons. Up to 2 million birds arrive each year to nest in some of North America’s most productive waterfowl breeding grounds. Along with salmon, moose and other wildlife, they provide food for the human residents of the region, where a half-gallon of milk can cost $7.99.