Alaska (//) is a state in the United States, situated in the northwest extremity of the North American continent, with the international boundary with Canada to the east, the Arctic Ocean to the north, and the Pacific Ocean to the west and south, with Russia 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; it has these resources in abundance.
Alaska was purchased from Russia on March 30, 1867, for $7.2 million ($118 million adjusted for inflation) at approximately two cents per acre ($4.74/km²). The land went through several administrative changes before becoming an organized (or incorporated) territory on May 11, 1912, and the 49th state of the U.S. on January 3, 1959.
The name "Alaska" (Аляска) was already introduced in the Russian colonial period, when it was used only for the peninsula and is derived from the Aleut alaxsxaq, meaning "the mainland" or, more literally, "the object towards which the action of the sea is directed". It is also known as Alyeska, the "great land", an Aleut word derived from the same root.
Alaska has a longer coastline than all the other U.S. states combined. It is the only non-contiguous U.S. state on continental North America; about 500 miles (800 km) of British Columbia (Canada) separates Alaska from Washington state. Alaska is thus an exclave of the United States, possibly the largest exclave in the world. It is technically part of the continental U.S., but is often not included in colloquial use; Alaska is not part of the contiguous U.S., often called "the Lower 48". The capital city, Juneau, is situated on the mainland of the North American continent, but is not connected by road to the rest of the North American highway system.