Overview of US Minor Outlying Islands

Profile

United States Minor Outlying Islands is an ISO statistical classification referring to Wake Island, Midway Atoll, Johnston Atoll, Palmyra Atoll, Kingman Reef, Baker Island, Howland Island, Jarvis Island, and Navassa Island—nine islands (reefs) in total. Most are located in tropical waters near the equator, with a combined area of less than 40km². There are no residents, with only U.S. Fish and Wildlife Service (USFWS) staff, researchers, and U.S. military personnel stationed seasonally or rotationally. The islands are designated as national wildlife refuges, preserving unique seabird nesting sites and coral reef ecosystems found in remote oceanic islands. Meanwhile, Wake Island and Midway Atoll are known as fierce battlefields of World War II, with numerous historic sites remaining.

Official name: United States Minor Outlying Islands
Common name: US Minor Outlying Islands
Numeric code: 581
Alpha-3 code: UMI
Alpha-2 code: UM
Population: Permanent residents fewer than 300 (researchers, military personnel, etc.) (2023)
Population density: Less than approximately 9 people/km²
Primary languages: English
Major religions
National anthem: The Star-Spangled Banner (sharing United States national anthem)
Calling code: +1
Internet TLD: .um（2008年廃止）

History

The U.S. claimed these islands as part of the Guano Islands Act and Pacific expansion from the mid-19th century, utilizing them as military bases and communications stations.

In the 19th century, the U.S. enacted the Guano Islands Act (1856) to mine guano (bird droppings) valued as fertilizer, declaring sovereignty over many uninhabited islands. This led to the incorporation of Baker Island and Howland Island among others. In the early 20th century, they were developed as relay points for transpacific aviation and undersea telegraph cables, with Wake Island and Midway Atoll becoming battlegrounds between Japan and the U.S. during World War II. During the Cold War, Johnston Atoll was used for nuclear and chemical weapons storage and disposal, with the military withdrawing in 2005. Currently, most are national wildlife refuges, with natural recovery progressing under strict management.

Geography & climate

Most are low-lying coral reefs or small volcanic rock islands with elevations of a few meters. Characterized by lagoons and extensive coral reefs developed around island perimeters.

Tropical marine climate (hot and humid year-round, squall-pattern rainfall)

Area: Oceania / North America (including Caribbean islands) / 34 km²
Coastal status: Yes

Natural resources

Guano deposits, Abundant seabird nesting sites, Coral reef ecosystems, Tropical fish resources, Potential wind energy, Potential solar energy, Mangrove forests (Palmyra Atoll), Large migratory fish migration routes, Deep-sea biodiversity, Clear lagoon water quality

Politics

Government: Unincorporated territories of the United States (Palmyra Atoll only is incorporated territory)

Economy

Currency: United States Dollar (USD)

GDP (nominal):

GDP (PPP):

Language & timezone

Primary languages: English

Time zone: UTC−11 (Midway Atoll), UTC−05 (Navassa Island), UTC+12 (Wake Island)

Culture & customs

Ethnic groups

Stationed personnel (mostly U.S. nationals)

National sports

No sports culture particularly formed