The island is 4,162 sq. km (1,607 sq. miles) in size. The island is about 160 km (100 miles) long and 48 km (30 miles) wide. Its center is near 57°0' North 135°0' West. The island's largest town is Sitka.
Lumbering, trapping, fishing and fish processing are important industries on the island.
The first European settlement on island was established in 1741 by Russians. Baranov Island was the center of Russian activity in North America during the period from 1804–1867 and was the headquarters of the Russian fur-trading interest, the Russian-American Company.
The islands are the tops of the submerged coastal mountains that rise steeply from the Pacific Ocean.
All the islands are rugged, densely forested, and have an abundance of wildlife.
The Tsimshian people found on Annette Island are not originally from the area, having immigrated to the region from British Columbia in the late 19th century.