The Beaufort Sea lies off the coast of Alaska and the Canadian territories of Yukon and North-West. The exact course of the border is still disputed between Canada and the USA. It received its name from the hydrographer Sir Francis Beaufort. As part of the Arctic Ocean, the Beaufort Sea, which covers about 476,000 km² and is up to 4,683 m deep, is frozen most of the year. Despite the cold, whales, crustaceans and various plankton species inhabit the lake. Polar bears are frequently sighted on the shore. There is also a rich supply of resources such as oil and natural gas. With the beginning of offshore drilling of oil and natural gas, some settlements were established around the Beaufort Sea.