Historically, the Eyak roamed approximately 300 miles, by the shores of the Gulf of Alaska coast. Their territory ranged from Pt. Whitshed along the Heney and Eccles Ranges; to Cordova, Eyak Lake, and the Copper River Delta; and all the way down to Yakutat Bay and east to the Italio River. They also traveled south down the Alaskan coast and into California. Elder Mae Lange, born and raised in Katalla, recalls stories of traveling in a large open skin boat from Katalla to Middleton Island. At one time the Eyak expanded their territory west to Port Gravina.

The Eyak were a tribe distinct in language and culture from the neighboring Chugach Eskimo on the west, Tlingit tribes to the east, and the Athabascan (Ahtna) tribes of the Copper River Basin to the north. However, they interacted with the Tlingit and Athabascan, sharing the Gulf Coast and Copper River territory, and they acted as middlemen between the Chugach and the Athabascan. The settlement of Cordova in 1909 and the completion of the Copper River & Northwestern Railroad in 1911 (which ran between the Cordova and the Kennecott copper mines) deeply impacted the Eyak peoples. Diseases introduced by Europeans decimated the Eyak population. At one point, the Eyak language was lost to all but one fluent speaker, Marie Smith. It has been documented and preserved through the work of Dr. Michael Krauss of the Alaska Native Language Center and the Eyak people.