Byrdbreen is, at about 40 miles (64.4 km) long and 11 miles (17.7 km) wide, the largest glacier flowing northwest between Mount Bergersen

Mount Bergersen

Mount Bergersen is a large mountain rising to 3,170 m, standing at the west side of Byrdbreen in the Sor Rondane Mountains. It was mapped by Norwegian cartographers in 1946 from air photos taken by the Lars Christensen Expedition, 1936–37, and named for Ambassador Birger Bergersen, chairman of the...

 and Balchen Mountain

Balchen Mountain

Balchen Mountain is a mountain, high, standing at the east side of Byrdbreen in the Sør Rondane Mountains. It was mapped by Norwegian cartographers in 1957 from air photos taken by U.S. Navy Operation Highjump, 1946–47, and named for Bernt Balchen, famous Norwegian polar aviator and chief pilot...

 in the Sør Rondane Mountains. It was mapped by Norwegian cartographers in 1957 from air photos taken by U.S. Navy Operation Highjump, 1946–47, and named for R. Admiral Richard E. Byrd, U.S. Navy, commander of U.S. Navy Operation Highjump.