20 miles long.
Aleut name published as Agataku by Reverend Coxe (1787, p. 50). The early Russians called the island Ostrov Kruglyy, meaning round island. The island probably was discovered September 21, 1741 (Old Style (O.S.) calendar) by the crew of the St. Paul, under the command of Captain A. I. Chirikov (Golder, 1922, v. 1, p. 307). Marcus Baker (1906, p. 82) indicates that Agattu may have been the island named St. Abraham by Vitus Bering, October 29, 1741 (Old Style (O.S.) calendar), but Golder (1922, v. 1, p. 202) attributes that distinction to Shemya Island.