In 1997 an American salvager made a claim to Navassa to the Department of State based on the Guano Islands Act. On March 27, 1997, the Department of the Interior rejected the claim on the basis that the Guano Islands Act applies only to islands which, at the time of the claim, are not “appertaining to” the United States. The department’s opinion said that Navassa is and remains a U.S. possession “appertaining to” the United States and is “unavailable to be claimed” under the Guano Islands Act.
A 1998 scientific expedition led by the Center for Marine Conservation in Washington, D.C. described Navassa as “a unique preserve of Caribbean biodiversity.” The island’s land and offshore ecosystems have survived the 20th century virtually untouched.
In September, 1999, the United States Fish and Wildlife Service established the Navassa Island National Wildlife Refuge, which encompasses 1,344 acres of land and a 12 nautical mile radius of marine habitat around the island. Later that year, full administrative responsibility for Navassa was transferred from the Office of Insular Affairs to the U.S. Fish and Wildlife Service.
Due to hazardous coastal conditions, and for preservation of species habitat, the refuge is closed to the general public. Visitors need permission from the Fish and Wildlife Office in Boquerón, Puerto Rico to enter its territorial waters or land.
Since it became a National Wildlife Refuge, amateur radio operators have repeatedly been denied entry. In October 2014 permission was granted for a two-week DX-pedition in February 2015. The operation made 138,409 contacts.