Baker Island National Wildlife Refuge, 20 miles north of the equator and 1,600 miles southwest of Honolulu, is a nearly level saucer-shaped 405-acre island surrounded by a narrow reef and 30,504 acres of submerged land. Most of the refuge is marine habitat, including extensive coral reefs and other inshore tropical ocean habitats. Uninhabited, it is low, flat, sandy, and vegetated only by grasses, prostrate vines, and low-growing shrubs due to the scant rainfall and intense sun. The refuge provides nesting and roosting habitat for about 20 species of seabirds and shorebirds. Threatened green sea turtles and endangered hawksbill sea turtles forage in the shallow waters of the reef with hundreds of species of fish, corals, and other invertebrates. Visitation is by special use permit only. The refuge is part of the Pacific Remote Islands National Wildlife Refuge Complex, whose office is in Honolulu.

The island is uninhabited, and entry is by permit only. U.S. Fish and Wildlife Service personnel visit Baker about every 2 years, though occasionally scientists and researchers team up to share transportation costs to the island more frequently. From Honolulu, it is only accessible by an 8-day ship voyage.