Dawes Glacier originates from the Stikine Icefield near the Alaska-Canada boundary and flows northwest for 20 miles (32 km) to tidewater in Endicott Arm, about 100 miles (161 km) northeast of Sitka and 80 miles (129 km) southeast of Juneau, Alaska. The glacier was named in 1891 by the U.S. Coast and Geodetic Survey after Henry L. Dawes, a Massachusetts lawyer and statesman known for the Dawes Act of 1887, which aimed to assimilate Native Americans by ending tribal government and communal land ownership. Originally, John Muir named it the Young Glacier in honor of Reverend S. Hall Young, his traveling companion in Southeast Alaska in 1880. Endicott Arm was named in 1889 by Lieutenant Commander Henry B. Mansfield of the US Coast and Geodetic Survey Ship Carlile P. Patterson, after William C. Endicott, the Secretary of War under President Grover Cleveland from 1885 to 1889. The Stikine Icefield derives its name from the Stikine River, or Stik-Heen, which means “Great River” in the Tlingit language. The bedrock geology of southeastern Alaska is a complex assembly of micro-terranes accreted onto North America during the late Mesozoic era. These terranes are bounded by strike-slip faults and are intruded by granitic plutons. The Stikine Icefield overlays three major micro-terranes, each representing distinct geological assemblages. East of Frederick Sound, and largely covered by the icefield, lie the high-grade metamorphic and intrusive rocks of the Coast Mountains Batholith. This batholith formed during the late Cretaceous and early Paleogene periods and primarily consists of hornblende-rich tonalites, quartz diorites, and granodiorites. These rocks intrude the surrounding medium- to high-grade metamorphic formations.

The Stikine Icefield is located in the Coast Mountains of southeastern Alaska and northwestern British Columbia, between Juneau and Wrangell. It is bordered on the north by the Taku River, on the east and south by the Stikine River, and on the west by the Inside Passage of the Pacific Ocean through the Alexander Archipelago. Near the ocean, peaks of the Coast Mountains rise between 4,900 and 12,000 feet (1,500 and 3,100 m), forming a barrier that intercepts moisture-laden clouds from the Gulf of Alaska. At these elevations, precipitation falls as snow, accumulating to form the icefield, which covers more than 8,400 acres (3,400 ha). Major glaciers originating in the Stikine Icefield include Dawes Glacier, 1,614 acres (653 ha), Sawyer Glacier, 986 acres (399 ha), South Sawyer Glacier, 1,688 acres (683 ha), Baird Glacier, 1,987 acres (784 ha), Patterson Glacier, 158 acres (64 ha), Muddy Glacier, 37 acres (15 ha), LeConte Glacier, 1,166 acres (472 ha), and Shakes Glacier, 198 acres (80 ha), all on the Alaska side. Glaciers on the British Columbia side of the mountains include Great Glacier, covering 435 acres (176 ha); Flood Glacier, 91 acres (37 ha); and Mud Glacier, 111 acres (45 ha). Many large westward-flowing glaciers end in deep, sinuous fjords, such as Endicott Arm, carved during successive Pleistocene glaciations. The largest glaciers in the region terminate in the ocean, losing substantial volumes of ice to calving. LeConte Glacier is the southernmost tidewater-calving glacier in the Northern Hemisphere. To the south and east in British Columbia, many glaciers end in moraine-dammed lakes.

The majority of glaciers in southeast Alaska and adjoining Canada are thinning, with many doing so rapidly. Significant ice losses in Southeast Alaska are occurring at tidewater glaciers like LeConte, South Sawyer, and Dawes. Tidewater glaciers become unstable when their terminus retreats from a protective shoal into a deep basin, triggering rapid calving. Although retreat may initially be triggered by climate, these calving retreats eventually become independent of it, following a tidewater glacier cycle. Once the retreat phase begins, positive feedback increases as surface slopes and flow velocities rise at the terminus and along the glacier, causing substantial drawdown of the parent ice field. Glaciers in Alaska and northwest Canada contribute disproportionately to global sea-level rise relative to their surface area. Glaciers rank among the largest contributors to sea level rise, following the Greenland and Antarctica ice sheets. The partitioning of glacier mass loss between land, lake, and tidewater (marine) terminating glaciers in this region has only recently been determined. Thinning rates reveal that the Stikine Icefield’s mass decreased at an average rate of 3.3 gigatons per year from 2000 to 2014. Marine-terminating glaciers, which comprise about 30% of the Stikine Icefield’s glaciated area, account for 45% of this mass loss. In contrast, land- and lake-terminating glaciers make up 50% and 20% of the surface area, respectively, and each contributes 27% to the mass loss. The four largest marine-terminating glaciers—North Sawyer, South Sawyer, Dawes, and LeConte—exhibit high terminus velocities compared to other glaciers in the icefield. This suggests that ice-mass loss, or ablation, at the terminus may partly explain the greater thinning observed in marine-terminating glaciers compared to land-terminating ice streams. Read more here and here. Explore more of Dawes Glacier and Endicott Arm here: