in SE end of Chugach Mts., trends SW to head of Glacier River, 12 mi. NW of Whittier, Chugach Mts.
Local name reported on recent U.S. Geological Survey (USGS) maps; derived from nearby Twentymile River.
Blackstone Bay, Emerald Bay, Hollow Bight, Passage Canal, Poe Bay, Shotgun Cove, Smitty's Cove, Squirrel Cove,
Capes:Bur Point, Decision Point, Gradual Point, Neptune Point, Squirrel Point, Strong Point, Trinity Point,
Cities:Glaciers:Billings Glacier, Byron Glacier, Glacier G211176E60873N, Glacier G211226E60788N, Glacier G211235E60779N, Glacier G211254E60750N, Glacier G211360E60891N, Harriman Glacier, Lake George Glacier, Learnard Glacier, Lowell Glacier, Pigot Glacier, Portage Glacier, Roaring Glacier, Seth Glacier, Shakespeare Glacier, Stairway Glacier, Surprise Glacier, Twentymile Glacier, Whittier Glacier,
Islands:Lakes:Carmen Lake, Divide Lake, Glenn Lake, Portage Lake,
Mine:Mountains:Baird Peak, Bard Peak, Begich Peak, Boggs Peak, Mount Luther Kelly, Maynard Mountain, Shakespeare Shoulder,
Parks:Decision Point State Marine Park,
Mountain Passes:Peaks:Finch Peak, Learnard Peak, Lowell Peak, Mismapped Mountain, Pass Out Peak, Passage Peak, Pico España, Roost, Vigesimal Peak, White Crown,
Rivers:South Fork Upper Carmen River, Upper Carmen River,
Streams:Billings Creek, Cove Creek, Placer Creek, Whittier Creek,
Routes:Byron Glacier Trail, Portage Pass Trail,
Valleys: