Alitak Lagoon lies 1 mile (1.6 km) northeast of Cape Alitak on Tanner Head at the southern end of Kodiak Island, 93 miles (150 km) southwest of the community of Kodiak, Alaska. The lagoon is 4 miles (6.5 km) long and located approximately 3 miles (4.8 km) west of Alitak Bay. The name is derived from Cape Alitak and was first published in 1934 by the U.S. Coast and Geodetic Survey.

Cape Alitak is a point of land on Tanner Head, an island approximately 4.2 miles (6.8 km) long, connected to Kodiak Island by a 4.3-mile (6.9 km) barrier beach. The island was named after Lieutenant Commander Zera Luther Tanner in 1900 by Jefferson F. Moser of the U.S. Navy, who commanded the Albatross. Cape Alitak is an extension of Tanner Head, separated by Rodman Reach, which is part of Alitak Lagoon, except for a barrier beach on the west. The cape is bounded by Alitak Bay to the east, the southern end of Shelikof Strait to the west, and Sitkinak Strait to the south, which separates Kodiak Island from the Trinity Islands.

The cape is renowned for its remarkable collection of prehistoric petroglyphs, which depict a diverse array of shapes, including animals, humans, and seemingly abstract geometric figures. In 2011, archaeologists from the Alutiiq Museum in Kodiak conducted a detailed survey of the area. They identified 13 different petroglyph locations and found evidence of prehistoric habitation. This petroglyph site was subsequently listed on the National Register of Historic Places in 2013. Read more here and here. Explore more of Alitak Lagoon and Tanner Head here: