The Eyak occupied a small coastal area surrounding the Copper River Delta. They are linguistically related to the Athabaskans but constitute a separate branch of the Athabaskan-Eyak language family.
Living in a different environment from the boreal forest, the Eyak adapted some of the customs of their Alutiiq Eskimo neighbors to the west and their Tlingit neighbors to the east. The Eyak depended on the ocean and Copper River Delta for most of their food. Salmon was their chief food. In addition, they fished for halibut with hooks and lines from canoes, hunted seals and sea otters, and collected clams from the beaches. They netted eulachon from the Copper River between February and April. In the fall, they hunted ducks, geese, and swans. Grouse and ptarmigan were hunted year-round. Dogs aided in hunting for brown and black bears. Beaver, fox, lynx, marten, muskrat, and weasel were taken with deadfalls and snares.
The Eyak had several permanent settlements and several summer camps. The permanent settlements had rectangular houses with walls of vertical planks set into horizontal grooved poles at the top and bottom. Central smokeholes in the roofs of such structures, reached by ladders, provided ventilation and access.
Their central location between three larger Native groups allowed the Eyak to serve as go-betweens in trade between the Chugach Eskimos of Prince William Sound, the Tlingit of Southeast Alaskan, and the Athabaskans of the Interior.