The jet crosses the Brooks Range and descends through the clouds above the Arctic's flat coastal plain. The winter world lingers into April. The ground is like the clouds, white and rumpled like a sheet, and it is hard to discern where sky and tundra meet. And then Prudhoe Bay appears. It was the first major oil field developed on the North Slope of the Brooks Range in the late 1960s and is still the most productive field in the United States.
Nobody knows how much oil is buried beneath the refuge.
The opponents of drilling in the refuge point out that it would not save the nation from dependence on foreign oil, but would supply only a few months or years of crude. The United States produces 6.2 million barrels a day and uses 18.9 million barrels, making it the world's leading consumer. The United States has only 2 or 3 percent of the world's known oil reserves. Yet the possible reserves in ANWR are not trivial. Alpine, the largest discovery in a decade in the United States, contains 500 million barrels.