They are located southeast of Attu Island and northeast of Agattu Island, near 52°44′06″N 173°59′28″E / 52.73500°N 173.99111°E / 52.73500; 173.99111.

The Semichi Islands are an important nesting area for red-faced cormorants and glaucous-winged gulls.

They also provides important habitat for waterfowl: The Aleutian subspecies of cackling goose nests on the islands in significant numbers, and common eider and emperor goose winter in the area.

Black oystercatchers are also found in significant numbers.

This article about a location in the Aleutians West Census Area, Alaska is a stub.