7 mi. SE of Snettisham Peninsula, and 50 mi. SE of Juneau, Coast Mts.
Named for Sumdum Glacier on its southern flank and published in 1895 by U.S. Coast and Geodetic Survey (USC&GS).
Dry Bay, Endicott Arm, Holkham Bay, Sanford Cove, Tracy Arm, Williams Cove,
Capes:Point Astley, Rock Point, Whiting Point,
Glaciers:Islands:Bushy Islands, Harbor Island, Round Islet, Sumdum Island,
Lakes:Icefall Lake, Lower Sweetheart Lake, Taylor Lake, Upper Sweetheart Lake,
Locales:Mine:Mountains:Streams: