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National Park of American Samoa

American Samoa · Established October 31, 1988

Rainforest cliffs, coral reefs and flying foxes at the edge of Polynesia

Area
8,257 acres
Established
October 31, 1988
Recreation visits
43,258 / yr
State
American Samoa
Highest point
Lata Mountain, Taʻū, 3,170 ft (966 m)
Lowest point
Sea level (Pacific Ocean)

American Samoa Weather Forecast

The National Weather Service gridded forecast does not cover American Samoa. See the park's current conditions.

Seven-day outlook at the park's reference point (-14.229, -169.850). Elevation changes everything in the mountains — expect colder, windier and wetter conditions on high ground.

Map of National Park of American Samoa

Shaded relief map of National Park of American Samoa with the park boundary and major features
National ParkAmerican Samoa
020 mi
Shaded relief · Copernicus DEM · NPS boundary (dashed)Open in the Park Atlas →

The Park

The National Park of American Samoa is the only U.S. national park south of the equator, spread across three volcanic islands in the South Pacific: Tutuila, Ofu and Taʻū. Its land is not owned by the federal government but leased from Samoan villages, so the park protects both a living culture and a landscape of steep rainforest, white-sand beaches and fringing coral reefs.

Here the forest belongs to the Old World tropics, a paleotropical rainforest whose flowers and fruits are pollinated and dispersed largely by flying foxes, the large fruit bats Samoans call peʻa. Offshore, reefs host hundreds of species of fish and some 200 kinds of coral. On Taʻū, sea cliffs rise more than 3,000 feet from the ocean to the cloud forest of Lata Mountain, the highest point in American Samoa.

Geography

American Samoa lies about 2,600 miles southwest of Hawaiʻi, between the equator and the Tropic of Capricorn. The park covers roughly 8,257 acres across three units, a substantial part of it coral reef and ocean.

The Tutuila unit stretches along the rugged north coast of the territory's main island, above the village of Vatia, rising to Mount ʻAlava above Pago Pago Harbor and including tiny, cliff-bound Pola Island. About 60 miles east, the Manuʻa Islands hold the other two units: a beach and lagoon on the south shore of Ofu, and much of the eastern and southern part of Taʻū, from the coast near Saua up to Lata Mountain.

All the islands are high, deeply eroded volcanoes with narrow coastal flats, and nearly all of the land is steep. Fringing reefs hug their shores, and on Ofu a sheltered lagoon protects some of the healthiest corals in the territory.

Landmarks

  • Mount ʻAlavaPeak · 1,610 ftA forested ridge summit in the Tutuila unit looking down over Pago Pago Harbor.
  • VatiaCoastA village on Tutuila's north coast, surrounded by the park and facing Pola Island.
  • Pola IslandIslandA sheer volcanic sea stack where seabirds nest on vertical cliffs.
  • Vaiʻava StraitCoastThe narrow channel between Tutuila and Pola Island, framed by towering cliffs.
  • Ofu unit beach and lagoonCoastThe park unit on the south shore of Ofu, where a white-sand beach fronts a coral lagoon beneath the island’s steep slopes.
  • TaʻūIslandThe easternmost high island of the Samoan chain, a shield volcano whose southern flank is edged by huge sea cliffs.
  • Lata MountainPeak · 3,170 ftThe highest point in American Samoa, crowned by misty cloud forest.
  • SauaCoastA rocky coastal site on Taʻū revered in Samoan tradition as a place of deep cultural significance.

Geology

The Samoan Islands are the tops of enormous shield volcanoes built from the floor of the Pacific. Like Hawaiʻi, they are thought to have formed as the Pacific Plate moved over a hotspot, and the islands generally grow older to the west. The hotspot's current activity is believed to lie beneath Vailuluʻu, an active submarine volcano about 45 kilometers east of Taʻū.

The three park islands are geologically young. On Ofu, volcanic breccias and plugs of the Pliocene Asaga Formation are among the oldest rocks in the park. Tutuila was built largely by the Pago Volcanics, lava flows and tuffs of Pliocene to Pleistocene age, along with later trachyte plugs, dikes and pumice. Taʻū is the youngest, with Pleistocene lavas of the Lata Formation that erupted in and after the collapse of its summit caldera, pāhoehoe flows of the Luatele Formation, and Holocene flows of the Fitiʻuta Formation.

Erosion has been relentless. Heavy tropical rain has carved deep valleys and knife-edged ridges, and waves have cut sea cliffs that on Taʻū's south side rise more than 3,000 feet, among the tallest in the world. As the volcanoes cooled and slowly subsided, fringing coral reefs grew along their shores.

The volcanic system is not finished. The last eruption on Tutuila is estimated at 1,700 to 1,400 years ago, a submarine eruption broke the sea near Olosega in 1866, and Vailuluʻu has built a new cone called Nafanua inside its summit crater.

Deep time

  1. PlioceneVolcanic breccias and plugs of the Asaga Formation form on Ofu, among the oldest rocks in the park.
  2. Pliocene to PleistoceneLava flows and tuffs of the Pago Volcanics build the island of Tutuila.
  3. PleistoceneTaʻū's shield grows; lavas of the Lata Formation erupt within and after its summit caldera.
  4. HoloceneLava flows of the Fitiʻuta Formation erupt on Taʻū.
  5. About 1,700 to 1,400 years agoTutuila experiences its most recent volcanic eruption.
  6. 1866A submarine eruption about 2 miles southeast of Olosega hurls jets of water and ash into the air for at least a week.
  7. Early 2000sScientists document a new volcanic cone, Nafanua, growing inside the crater of Vailuluʻu seamount east of Taʻū.

The rocks

  • Asaga FormationPliocene
    Volcanic breccias and plugs on Ofu, among the oldest exposures in the park.
  • Pago VolcanicsPliocene to Pleistocene
    The lava flows, tuffs and dikes that make up most of Tutuila.
  • Lata FormationPleistocene
    Intra-caldera and post-caldera lava flows forming the high interior of Taʻū.
  • Luatele FormationPleistocene
    Smooth, ropy pāhoehoe lava flows on Taʻū.
  • Fitiʻuta FormationHolocene
    The youngest lava flows on Taʻū, near its northeastern coast.
  • Fringing coral reefsHolocene to present
    Living reefs growing on the volcanic shelves of Tutuila, Ofu and Taʻū.

Trees, Plants & Ecosystems

  • 590vascular plant species recorded
  • Coral reefs and lagoonsShallow waters off all three islands
    Fringing reefs and Ofu's lagoon host some 200 coral species, giant clams, sea turtles and reef sharks.
  • Coastal and littoral forestBeaches, rocky shores and sea cliffs
    Salt-tolerant trees like futu, fetau and puʻa, with beach morning glory on the sand and seabirds on the cliffs.
  • Lowland rainforestCoastal slopes and valleys
    Tall paleotropical forest of tava, asi and banyans pollinated and seeded by flying foxes and fruit doves.
  • Montane rainforestRidges and upper slopes of Tutuila and Taʻū
    Wetter, shorter forest rich in tree ferns, climbing ʻieʻie and epiphytes.
  • Cloud forestSummit of Lata Mountain on Taʻū, up to 3,170 ft
    Constantly misty, moss-draped forest at the highest elevations in American Samoa.

Trees

  • TavaPometia pinnataA dominant canopy tree of lowland rainforest with edible fruit favored by flying foxes.
  • AsiSyzygium inophylloidesA tall rainforest tree in the myrtle family, important in Samoan forests.
  • Maota mamalaDysoxylum samoenseA native mahogany-family canopy tree of lowland and montane forest.
  • Aoa (banyan)Ficus prolixaA strangler fig whose aerial roots form massive, cathedral-like trunks.
  • ʻAuʻauliDiospyros samoensisA native ebony-family tree of coastal and lowland forest.
  • Futu (fish-poison tree)Barringtonia asiaticaA coastal tree with large, box-shaped floating fruits and showy night-blooming flowers.
  • FetauCalophyllum inophyllumA spreading shoreline tree with glossy leaves and fragrant white flowers.
  • Puʻa (Chinese lantern tree)Hernandia nymphaeifoliaA littoral tree whose fruits sit inside lantern-like cups.
  • Puʻa vaiPisonia grandisA soft-wooded coastal tree often associated with nesting seabirds.
  • AfaNeonauclea forsteriA native tree of lowland forests and valley bottoms.
  • TavaiRhus taitensisA fast-growing native tree that colonizes gaps after storms.
  • Olioli (tree fern)Cyathea lunulataA tree fern of wet montane and cloud forests.

Wildflowers, shrubs & other plants

  • Fasa (screwpine)Pandanus tectoriusA stilt-rooted coastal plant whose leaves are woven into Samoan mats.
  • ʻIeʻieFreycinetia storckiiA climbing pandan that festoons rainforest trees and is pollinated by flying foxes.
  • Laugapapa (bird's nest fern)Asplenium nidusA large epiphytic fern forming green rosettes on tree trunks.
  • Gase (king fern)Angiopteris evectaA giant fern with fronds several meters long in wet ravines.
  • Saua (false staghorn fern)Dicranopteris linearisForms dense thickets on open, disturbed ridges.
  • LaufaoHeliconia laufaoA native heliconia with paddle-shaped leaves in forest openings.
  • Fau (beach hibiscus)Hibiscus tiliaceusA coastal tree-like shrub whose bark fiber was traditionally used for cordage.
  • NonuMorinda citrifoliaA shrub with lumpy fruit valued in traditional Samoan medicine.
  • Toʻitoʻi (beach naupaka)Scaevola taccadaA salt-tolerant shrub stabilizing beaches with half-moon white flowers.
  • Beach morning gloryIpomoea pes-capraeA trailing vine with pink flowers creeping over sand.
  • Fue vaoMerremia peltataA fast-growing vine that can smother forest canopy after storms.
  • Philippine ground orchidSpathoglottis plicataA purple-flowered orchid of roadsides and open slopes.
  • Koster's curseClidemia hirtaAn invasive shrub that crowds out native understory plants.
  • Pulu mamoe (Panama rubber tree)Castilla elasticaAn invasive tree the park works to remove from native rainforest.

Wildlife

  • 10mammals
  • 39birds
  • 10reptiles
  • 1amphibians
  • 600fish

Mammals

  • Samoan flying fox (peʻa vao)Pteropus samoensisA day-flying fruit bat that soars over the forest and pollinates many native trees.
  • Pacific flying fox (peʻa fanua)Pteropus tonganusA mostly nocturnal fruit bat that roosts in large colonies.
  • Humpback whale (tafola)Megaptera novaeangliaeVisits Samoan waters to breed and calve during the Southern Hemisphere winter.
  • Spinner dolphinStenella longirostrisPods leap and spin offshore of the islands.
  • Polynesian rat (isumu)Rattus exulansA small rat carried across the Pacific by early voyagers.
  • Feral pig (puaʻa)Sus scrofaAn introduced animal that damages native forest by rooting up the understory.

Birds

  • Pacific imperial pigeon (lupe)Ducula pacificaA large pigeon that swallows whole fruits and spreads rainforest seeds.
  • Crimson-crowned fruit dove (manutagi)Ptilinopus porphyraceusA small green dove whose cooing fills the forest.
  • Many-colored fruit dove (manuma)Ptilinopus perousiiA strikingly patterned dove closely tied to fig trees.
  • Samoan starling (fuia)Aplonis atrifuscaA large, dark starling endemic to the Samoan archipelago.
  • Samoan myzomelaMyzomela nigriventrisA tiny red-and-black honeyeater that sips nectar from flowering trees.
  • Polynesian wattled honeyeater (iao)Foulehaio carunculatusA loud, common nectar-feeder of forests and gardens.
  • Blue-crowned lory (sega)Vini australisA small, bright green parrot feeding on flowers in coastal trees.
  • Samoan shrikebillClytorhynchus vitiensisA quiet forest songbird with a heavy, hooked bill.
  • Pacific kingfisher (tiʻotala)Todiramphus sacerA blue-and-white kingfisher perching along forest edges and shores.
  • Purple swamphen (manu aliʻi)Porphyrio porphyrioA large, purple rail of wet lowlands and plantations.
  • White-tailed tropicbird (tavaʻesina)Phaethon lepturusLong streaming tail feathers flash along the sea cliffs.
  • White tern (manu sina)Gygis albaAn ethereal white seabird that lays its egg directly on a bare branch.
  • Great frigatebird (atafa)Fregata minorSoars high on long, angular wings over the coast.
  • Pacific reef heronEgretta sacraStalks prey along reef flats and rocky shores.

Reptiles & amphibians

  • Pacific boa (gata)Candoia bibroniA harmless, forest-dwelling boa and the only land snake in Samoa.
  • Samoan skink (pili lape)Emoia samoensisA large skink of the rainforest floor and tree trunks.
  • Azure-tailed skinkEmoia cyanuraA small skink with a bright blue tail, common in sunny coastal areas.
  • Mourning gecko (moʻo)Lepidodactylus lugubrisA small gecko found on trees and buildings, able to reproduce without males.
  • Polynesian geckoGehyra oceanicaA larger gecko of forests and coastal trees.
  • Green sea turtle (fonu)Chelonia mydasGrazes seagrass and algae on the reefs and nests on remote beaches.
  • Hawksbill sea turtleEretmochelys imbricataA critically endangered turtle that feeds on sponges in coral reefs.
  • Cane toad (lage)Bufo marinusThe only amphibian in the park, a nonnative species introduced to the islands.

Fish

  • Bumphead parrotfishBolbometopon muricatumA giant parrotfish that crunches coral and produces sand.
  • Humphead wrasseCheilinus undulatusA massive, long-lived reef fish rare across much of its range.
  • Ornate butterflyfishChaetodon ornatissimusA brightly striped butterflyfish that feeds on coral polyps.
  • Convict tangAcanthurus triostegusA striped surgeonfish that grazes algae in schools on the reef flat.
  • Blacktip reef sharkCarcharhinus melanopterusA small shark patrolling shallow lagoons and reef edges.
  • Whitetip reef sharkTriaenodon obesusRests in reef caves by day and hunts at night.

Species totals are the park's certified NPSpecies checklist (occurrence: present).

Climate & When to Visit

American Samoa has a hot, humid tropical climate with warm temperatures all year and frequent rain. Showers may last only a few minutes or settle in for an entire day. Rainfall varies enormously with elevation and exposure, from about 125 inches a year in the drier lowlands to as much as 300 inches on the highest mountains.

The year divides into a long, wet and hotter season from October through May, when tropical storms and cyclones are more likely, and a slightly cooler, drier season from June through September, when southeast trade winds blow more steadily. Because the islands lie in the Southern Hemisphere, the drier months coincide with the northern summer.

  • Spring (March to May)
    The tail end of the wet season, still hot and humid with frequent showers and some tropical storm risk.
  • Summer (June to August)
    The coolest and driest part of the year, with steadier trade winds, the most comfortable hiking, and humpback whales offshore.
  • Autumn (September to November)
    A transition back to the wet season, which begins in October with increasing rain and humidity.
  • Winter (December to February)
    The heart of the wet season: hot, very humid, rainy, and the most likely time for tropical cyclones.
Weather hazards
Tropical cyclones
Monitor forecasts during the October to May wet season, when tropical storms are most frequent.
Flash floods and landslides
Heavy downpours on steep terrain can swell streams and loosen slopes; avoid stream crossings during intense rain.
Strong currents and reef hazards
Swim only in calm, protected areas, as reef channels can carry strong currents and waves break hard on the reef edge.
Heat and humidity
Hike early, drink plenty of water and expect trails to be muddy and slippery.
Earthquakes and tsunamis
These islands sit in a seismically active region; if you feel strong shaking near the coast, move to high ground.

American Samoa Questions

When is the best time to visit the National Park of American Samoa?

June through September is the slightly cooler and drier season, with steadier trade winds and fewer tropical storms. It is also when humpback whales visit. The park can be visited year-round, but October through May is wetter and more humid.

What is the weather like in American Samoa?

Expect warm to hot temperatures, high humidity and frequent showers all year. Annual rainfall ranges from about 125 inches in drier areas to 300 inches on the mountains, and tropical storms are most likely from October to May.

What are peʻa?

Peʻa are flying foxes, large fruit bats. The Samoan flying fox often flies by day over the rainforest, while the Pacific flying fox is mostly active at night. Both are vital pollinators and seed dispersers for the park's forests.

How were the islands of American Samoa formed?

They are the tops of large shield volcanoes built by eruptions from the ocean floor, likely over a hotspot now located beneath Vailuluʻu seamount east of Taʻū. Rain and waves have since carved deep valleys and towering sea cliffs, and coral reefs have grown along the shores.

Can you snorkel in the National Park of American Samoa?

Yes. The lagoon along Ofu's south shore is known for clear water and vibrant corals, and reef flats elsewhere offer good snorkeling in calm conditions. Respect village customs, ask permission where needed, and watch for currents.

Why does the park lease its land?

In Samoan tradition, land is communally held by families and villages. The park operates under a long-term lease from village councils, so it protects both natural resources and faʻasamoa, the Samoan way of life.

More parks in the Pacific Islands

← Acadia National Park Arches National Park →

Sources: www.nps.gov · www.nps.gov · www.usgs.gov · en.wikipedia.org · irmaservices.nps.gov · developer.nps.gov · Official NPS site