Its assets are in the huge Prudhoe Bay Oil Field and at the end of 2006 the Trust claimed to have proved reserves of 85.1 million barrels of crude oil .
The huge Prudhoe Bay Oil Field is the largest oil field in North America .
Its assets are in the huge Prudhoe Bay Oil Field , the largest oil field in North America , and at the end of 2006 the Trust claimed to have proved reserves of 85.1 million barrels of crude oil .