Coco Harbor is an estuary that extends west for 3 miles (4.8 km) from Baldy Bay, off Tlevak Strait, on the east coast of Dall Island, Alaska. Baldy Bay was first reported by E.F. Dickins in 1907, and Coco Harbor was first published on charts in 1914 by U.S. Coast and Geodetic Survey.

Dall Island is off the southeast coast of Alaska, just west of Prince of Wales Island. Alaska Natives are known to have inhabited coastal caves on the island 2,000-3,000 years ago. Dall Island was first called Quadra, after Juan Francisco de la Bodega y Quadra, until 1879, when it was renamed in honor of William Healey Dall, a naturalist employed by the U.S. Coast and Geodetic Survey. Dall Island was thought to be part of Prince of Wales Island as recently as 1903, but is separated by Tlevak Narrows. Today, Dall Island is economically important for commercial fishing and limestone quarrying.

Cape Muzon is the southernmost point of Dall Island, and the western terminus of the marine boundary between the state of Alaska and the Canadian province of British Columbia. The boundary was settled by the decision of an arbitration tribunal under the Alaska Boundary Treaty of 1903. This line is also the northern boundary of the waters known as the Dixon Entrance. Read more here and here. Explore more of Coco Harbor here: