Prudhoe Bay, Alaska, is a US port on the Beaufort Sea (about 250 miles / 400 km north of the Arctic Circle) that is known for its nearby oil reserves.

The entire developed area covers about 350 sq. miles / 900 sq. km of the North Slope - a flat, tundra plain that extends north from Alaska's Brooks mountain range to the Arctic Ocean and west from the Canadian border to the Chukchi Sea.

Prudhoe Bay oil does not lie in underground "pools". The liquid is trapped with gas in the pores of the rocks and it flows under its own pressure. It's like opening a bottle of pop - when the cap is popped, the gas escapes upward and brings liquid with it. The gas also brings up oil and water.

Once oil is processed, it is sent to pump stations at the beginning of the Trans Alaska Pipeline. The pipleine crosses the entire state of Alaska, from Prudhoe Bay on the Beaufort Sea to Valdez on the Gulf of Alaska.

All wellheads and pumping stations are built on gravel pads to prevent damage to the tundra, and great concern is taken to not damage the fragile Arctic environment. However, accidents happen - in 1989, the tanker Exxon Valdez spilled nearly 11 million gallons / 42 million liters of North Slope oil into the waters of Prince William Sound.

As the Arctic opens up to industry, great care will have to be taken to assure that pollution does not damage the environment even more, and that pristine areas stay that way.