Alaska is a U.S. state situated in the northwest extremity of the North American continent. Bordering the state is Canada to the east, the Arctic Ocean to the north, and the Pacific Ocean to the west and south, with Russia (specifically, Siberia) further west across the Bering Strait. Alaska is the largest state in the United States by area, the 4th least populous and the least densely populated of the 50 United States. Approximately half of Alaska's 731,449 residents live within the Anchorage metropolitan area. Alaska's economy is dominated by the oil, natural gas, and fishing industries, resources which it has in abundance. Tourism is also a significant part of the economy.