In 1968, oil was discovered at Prudhoe Bay in the North Slope, located in northern Alaska between the Brooks Range Mountains and the Beaufort Sea (part of the Arctic Ocean). A consortium of oil companies planning to produce the oil determined that a pipeline offered the best means to transport crude oil from the North Slope to a navigable port in southern Alaska where it could be shipped by tanker to refineries in the continental United States. The pipeline route would cover 800 miles from Prudhoe Bay to the port of Valdez, the northernmost ice-free port in the United States.