Marie Byrd Land (MBL) is an unclaimed region of Antarctica. With an area of , it is the largest unclaimed territory on Earth. It was named after the wife of American naval officer Richard E. Byrd, who explored the region in the early 20th century. The territory lies in West Antarctica, east of the Ross Ice Shelf and the Ross Sea and south of the Pacific Ocean portion of the Antarctic or Southern Ocean, extending eastward approximately to a line between the head of the Ross Ice Shelf and Eights Coast. It stretches between 158°W and 103°24'W. The inclusion of the area between the Rockefeller Plateau and Eights Coast is based upon Byrd's exploration. Overview Because of its remoteness, even by Antarctic standards, most of Marie Byrd Land (the portion east of 150°W) has not been claimed by any sovereign state. It is by far the largest single unclaimed territory on Earth, with an area of (including Eights Coast, immediately east of Marie Byrd Land). In 1939, United States President Franklin D. Roosevelt instructed members of the United States Antarctic Service Expedition to take steps to claim some of Antarctica as United States territory. Although this appears to have been done by members of this and subsequent expeditions, these do not appear to have been formalized prior to 1959, when the Antarctic Treaty System was set up. Some publications in the United States have shown this as a United States territory in the intervening period, and the United States Department of Defense has stated that the United States has a solid basis for a claim in Antarctica resulting from its activities prior to 1959. The portion west of 150°W is part of Ross Dependency claimed by New Zealand. Five coastal areas are distinguished, which are listed from west to east: Exploration Marie Byrd Land was first explored from the west where it could be accessed from the Ross Sea. The far western coast of Marie Byrd Land was seen from the decks of Robert Falcon Scott's ship Discovery in 1902. He named the peninsula adjacent to the Ross Sea King Edward VII Land and the scattered outcrops that were within sight, the Alexandra Mountains. In 1911, during Roald Amundsen's South Pole expedition, Kristian Prestrud led a sledge party that visited these isolated outcrops (nunataks) in the region bordering the eastern Ross Sea and Ross Ice Shelf. At the same time