The Kingdom of Hawaii claimed the atoll in 1862, and the US included it among the Hawaiian Islands when it annexed the archipelago in 1898. The Hawaii Statehood Act of 1959 did not include Palmyra Atoll, which is now primarily privately owned by the Nature Conservancy with the rest owned by the US government and managed by the US Fish and Wildlife Service. These organizations are managing the atoll as a wildlife refuge. The lagoons and surrounding waters within the 12 nm US territorial seas were transferred to the US Fish and Wildlife Service and designated as a National Wildlife Refuge in January 2001. A new international climatology research station began development in 2005.
The high rainfall and resulting lush vegetation make the environment of this atoll unique among the US Pacific Island territories. It supports one of the largest remaining undisturbed stands of Pisonia beach forest in the Pacific.
The atoll is best known for an incident which took place in 1974, when a yachting couple who arrived at the atoll with supplies for a year's vacation, discovered another poorly-provisioned couple (one fleeing a prison sentence), who took their ship and apparently murdered them both. The crime was the subject of a book published in 1991.
Palmyra is equatorial and hot. It's located within the low pressure area of the Intertropical Convergence Zone (ITCZ) where the northeast and southeast trade winds meet, which has also contributed to its shores being littered with debris carried by Pacific currents. It is extremely wet with between 4,000-5,000 mm (160-200 in) of rainfall each year.
Palmyra consists of several low and nearly level sandy coral islands with narrow fringing reef that has developed at the top of a submerged volcanic mountain, rising steeply from the ocean floor. The islands are mostly connected (depending on the tide)
There is a 2000-meter unpaved airstrip on Cooper Island (the largest island, in the north), owned by the Nature Conservancy.
There are two moorings in the lagoon just off Cooper Island.
There is currently no economic activity on Palmyra Atoll.
There are no public accommodations on Palmyra Atoll; the limited facilities are for researchers' use only.