Kingman Reef is an uninhabited, barren, coral atoll with a deep lagoon 5 miles wide and 9э miles long. Located about 1,000 miles southwest of Honolulu, this triangular reef has a land area of only 0.01 square miles. It became a U.S. naval reservation in 1934. Pan American Airways used the lagoon just before World War II as a station for seaplanes flying between Hawaii and Samoa. Kingman consists of coral reefs and submerged lands. The reef is wet or awash most of the time, with a maximum elevation of about 1 meter. Besides a spectacular diversity of coral reef fishes, corals, and other marine organisms, it provides roosting, feeding, and other essential habitat for migratory seabirds, and supports migratory shorebirds and threatened Pacific green sea turtles.

The reef is closed to the public.