Fortress Island is one of the

San Juan Islands The San Juan Islands are an archipelago in the Pacific Northwest of the United States between the U.S. state of Washington and Vancouver Island, British Columbia, Canada. The San Juan Islands are part of Washington state, and form the core of ...

San Juan County, Washington San Juan County is a county located in the Salish Sea in the far northwestern corner of the U.S. state of Washington. As of the 2020 census, its population was 17,788. The county seat and only incorporated city is Friday Harbor, located on Sa ...

USA The United States of America (U.S.A. or USA), commonly known as the United States (U.S. or US) or America, is a country Continental United States, primarily located in North America. It consists of 50 U.S. state, states, a Washington, D.C., ...

. Located in Lopez Sound, the uninhabited, rocky island has a land area of and is almost completely devoid of vegetation. It is part of the Turtleback complex, a series of intrusive rocks in Lopez Sound formed out of crystallized molten magma that also includes Bird Rock, Low Island, and others. Fortress Island is part of the

San Juan Islands National Wildlife Refuge The San Juan Islands National Wildlife Refuge is in the San Juan Islands of the Salish Sea, north of Puget Sound, in the State of Washington. Created in 1976, it comprises 83 small, uninhabited islands, scattered throughout the San Juans, with a c ...

and is managed by the

U.S. Fish and Wildlife Service The United States Fish and Wildlife Service (USFWS or FWS) is an agency within the United States Department of the Interior dedicated to the management of fish, wildlife, and natural habitats. The mission of the agency is "working with oth ...

. As with almost all of the islands in the refuge, human access is prohibited and boats may not approach to within .

References

{{reflist San Juan Islands Uninhabited islands of Washington (state)