The feature may have been seen by Amundsen in 1911 .
Feature was observed and partially mapped by the Byrd Antarctic Expeditions of 1928 -- 30 and 1933 -- 35 .
The feature may have been seen by Amundsen in 1911 , and it was observed and partially mapped by the Byrd Antarctic Expeditions of 1928 -- 30 and 1933 -- 35 .