The uninhabited, rocky island has a land area of 3.5 acres (1.4 hectares).

[1] Deadman Island is an oystercatcher nesting site and is also a seal haulout.

As of 2008[update] it was being considered a possible location for the reintroduction of the Golden Paintbrush plant.

[2] The island is owned by the Nature Conservancy and public visitation is generally not allowed.

It is used as a research site by the Friday Harbor Laboratories.