Marie Byrd Land is the portion of West Antarctica lying east of the Ross Ice Shelf and the Ross Sea and south of the Pacific 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 the leading role of Rear Admiral Richard E. Byrd in the exploration of this area. The name was originally applied by Admiral Byrd in 1929, in honor of his wife, to the northwestern part of the area, the part that was explored in that year.