Glacier Bay National Park & Preserve

Alaska · Established December 2, 1980

Where tidewater ice gives way to forest in a single human lifetime

Area: 3,223,383 acres
Established: December 2, 1980
Recreation visits: 740,044 / yr
State: Alaska
Established: December 2, 1980 (national monument 1925)
Area: 3,223,383 acres (13,045 km²)

Glacier Bay Weather Forecast

Loading the National Weather Service forecast for Glacier Bay…

Seven-day outlook at the park's reference point (58.801, -136.841). Elevation changes everything in the mountains — expect colder, windier and wetter conditions on high ground.

Map of Glacier Bay National Park & Preserve

The Park

Glacier Bay is a landscape caught in motion. When Captain George Vancouver's crews sailed Icy Strait in 1794, the bay was little more than a notch in a wall of ice. Less than a century later John Muir paddled some 48 miles up newly opened water, and by 1916 the Grand Pacific Glacier had pulled back about 65 miles to the head of Tarr Inlet. Few places on Earth record faster glacial retreat.

What the ice left behind has become a living laboratory. Bare rock at the head of the bay gives way, mile by mile toward the mouth, to mats of mountain-avens, thickets of alder and willow, and finally mature forests of Sitka spruce and western hemlock. Humpback whales feed in the fjords, brown bears walk the tideflats, and the Huna Tlingit, whose homeland this is, still hold the bay close.

Geography

The park spans more than 3.2 million acres of Southeast Alaska between Icy Strait and the Canadian border. Its center is the Y-shaped fjord of Glacier Bay, whose West Arm reaches toward the Grand Pacific and Margerie glaciers while the East Arm, Muir Inlet, leads to glaciers that have now retreated onto land. To the west the Fairweather Range rises straight from the Gulf of Alaska to Mount Fairweather at 15,300 ft, one of the highest coastal mountains in the world.

Ice still covers much of the high country. The park counts 1,045 glaciers, seven of which reach tidewater: Margerie, Grand Pacific, McBride, Lamplugh, Johns Hopkins, Gilman and LaPerouse. On the outer coast, Lituya Bay is a steep-walled fjord famed for the giant wave of 1958, and in the park's northwestern corner the preserve takes in Dry Bay at the mouth of the Alsek River.

The monument was proclaimed in 1925, and Glacier Bay National Park and Preserve was established on December 2, 1980. It forms part of a World Heritage Site shared with neighboring parks in Alaska and Canada. Most visitors arrive by cruise ship or tour boat, while Bartlett Cove near Gustavus holds the park headquarters and lodge.

Landmarks

Mount FairweatherPeak · 15,300 ftThe park's highest summit, rising from the sea on the Alaska–British Columbia border.
Margerie GlacierGlacierA tidewater glacier at the head of the West Arm whose ice face calves thunderously into Tarr Inlet.
Johns Hopkins GlacierGlacierOne of the few glaciers in the park that has been advancing, in a narrow inlet crowded with harbor seals.
Lamplugh GlacierGlacierA broad tidewater glacier with a blue-banded face on the West Arm.
Reid GlacierGlacierA glacier in Reid Inlet whose snout now rests on a beach at low tide.
Muir GlacierGlacierOnce the grand tidewater glacier that drew Muir, it retreated onto land in the 1990s.
Brady GlacierGlacierA large glacier flowing south from the Brady Icefield toward Taylor Bay.
Tarr InletCoastThe northernmost reach of the West Arm, where tour boats pause before Margerie and Grand Pacific glaciers.
Muir InletCoastThe quiet East Arm, closed to motor vessels in parts and favored by kayakers.
Bartlett CoveCoastSite of park headquarters, the lodge and a mature spruce-hemlock rainforest near the bay's mouth.
South Marble IslandIslandA limestone island in the lower bay where Steller sea lions haul out and seabirds nest.
Lituya BayCoastAn outer-coast fjord where a 1958 earthquake-triggered rockfall sent water surging 1,720 feet up the opposite slope.
Mount CrillonPeakA heavily glaciated peak of the southern Fairweather Range.
Mount La PerousePeakA Fairweather Range summit named for the French navigator who reached Lituya Bay in 1786.

Geology

Glacier Bay sits where two great plates grind past each other. The Fairweather–Queen Charlotte fault system slices along the park's western edge, and the Pacific Plate slides northwest at roughly 50 millimeters a year, about the pace a fingernail grows. That motion has delivered four distinct slabs of crust, the Yakutat, Chugach, Wrangellia and Alexander terranes, and packed them against the continent in bands running northwest to southeast.

The rocks themselves are diverse. The west side of the bay holds a thick pile of Paleozoic limestone and argillite, from the Late Silurian Willoughby limestone to the Middle Devonian Black Cap limestone, and granite and other igneous rocks intrude them in many places. Continuing uplift has lifted the Fairweather Range into one of the steepest coastal escarpments on the planet.

Ice has been at work here for at least seven million years. About 20,000 years ago an ice sheet buried the entire region, and after a warm interval glaciers surged again during the Little Ice Age, filling the bay to its mouth by the late 1700s. Their rapid retreat since then has unloaded the crust, which is rebounding upward, and has exposed a sequence of fresh ground on which ecologists have watched soils and forests assemble from scratch.

Deep time

Silurian to Devonian periodsReef-building seas deposited the limestones now exposed along the West Arm.
At least 7 million years agoSnow began accumulating in the rising uplands and compacting into lasting glacial ice.
About 20,000 years agoAn ice sheet covered the whole Glacier Bay region.
1794Vancouver's expedition found Icy Strait choked with ice and the bay filled by a single great tidewater glacier.
1879John Muir found the ice had retreated roughly 48 miles up the bay.
1916Grand Pacific Glacier stood at the head of Tarr Inlet, about 65 miles from the bay's mouth.
July 9, 1958A major earthquake on the Fairweather fault triggered a rockslide into Lituya Bay and a wave that stripped forest 1,720 feet above the water.

The rocks

Willoughby limestoneLate Silurian
The oldest unit in the thick Paleozoic sequence on the west side of the bay.
Black Cap limestoneMiddle Devonian
The youngest limestone of that sequence, built from ancient marine sediment.
Alexander terranePaleozoic crustal block
An exotic slab of crust that forms much of the bay's eastern and central bedrock.
Wrangellia terranePaleozoic to Mesozoic crustal block
Part of a far-traveled volcanic arc sutured to Alaska.
Chugach terraneMesozoic crustal block
Scraped-off sea-floor sediments accreted to the continental margin.
Yakutat terraneCenozoic crustal block
The youngest terrane, still colliding with the coast along the Fairweather fault.

Trees, Plants & Ecosystems

530vascular plant species recorded

Fjords and marine watersSea level and below
Cold, nutrient-rich water stirred by tides and glacial runoff feeds plankton, herring, whales, seals and seabirds.
Newly deglaciated pioneer groundUpper bay near active ice
Bare till colonized first by mountain-avens, fireweed and mosses, whose nitrogen-fixing partners begin building soil.
Alder and willow thicketMid-bay slopes
Dense shrubs that follow the pioneers within decades and enrich the ground for conifers.
Coastal temperate rainforestLower bay and outer coast
Mature Sitka spruce and western hemlock forest carpeted with moss, blueberry and devil's club, as at Bartlett Cove.
Alpine tundra and icefieldsUpper slopes of the Fairweather Range
Heather meadows, rock and permanent snow above the forest, home to mountain goats and marmots.

Trees

Sitka sprucePicea sitchensisThe first large conifer to establish on land exposed by the ice, and the giant of the lower bay forests.
Western hemlockTsuga heterophyllaA shade-tolerant tree that eventually shares or takes over the canopy from spruce in older forest.
Mountain hemlockTsuga mertensianaGrows near treeline and in snowy subalpine hollows.
Black cottonwoodPopulus balsamifera ssp. trichocarpaColonizes outwash plains and river bars in the young landscape.
Red alderAlnus rubraA nitrogen-fixing tree of disturbed coastal ground.
Alaska yellow-cedarChamaecyparis nootkatensisA slow-growing, long-lived cedar of wet slopes and bog margins.
Shore pinePinus contortaA gnarled, stunted pine of muskeg bogs near the coast.

Wildflowers, shrubs & other plants

Drummond's mountain-avensDryas drummondiiA pioneer mat plant of fresh glacial till whose nodding yellow flowers turn to feathery seed heads.
FireweedChamerion angustifoliumMagenta spires on disturbed ground and young moraines.
Dwarf fireweedChamerion latifoliumLow, showy clumps on gravel bars and outwash.
Nootka lupineLupinus nootkatensisBlue-purple lupine of beach meadows and young slopes.
Sitka alderAlnus viridis ssp. sinuataThe shrub that forms dense thickets in mid-succession and adds nitrogen to thin soils.
Barclay's willowSalix barclayiOne of the common willows that cloak the recently deglaciated terrain.
Devil's clubOplopanax horridusA spiny, broad-leaved shrub of the moist rainforest understory.
SalmonberryRubus spectabilisPink-flowered cane shrub with orange-to-red berries along streams.
Alaska blueberryVaccinium ovalifoliumAn abundant forest shrub and a staple food for bears.
Yellow skunk-cabbageLysichiton americanusGlowing yellow hoods rise from forest bogs in early spring.
BunchberryCornus canadensisA tiny dogwood with white bracts that carpets the forest floor.
BuckbeanMenyanthes trifoliataA fringed-flowered plant of shallow pond margins and muskeg.
Lyngbye's sedgeCarex lyngbyeiA tall sedge of estuaries and salt marshes grazed by geese and bears.
Beach strawberryFragaria chiloensisCreeping wild strawberry of coastal dunes and beach edges.

Wildlife

42mammals
243birds
1amphibians
101fish

Mammals

Humpback whaleMegaptera novaeangliaeReturns each summer to feed on krill and small fish in the bay and Icy Strait.
Killer whaleOrcinus orcaPods travel through Icy Strait and occasionally enter the bay.
Harbor sealPhoca vitulinaHauls out and raises pups on floating ice near the tidewater glaciers.
Steller sea lionEumetopias jubatusCrowds rocky haulouts such as South Marble Island, roaring over the water.
Sea otterEnhydra lutrisOnce wiped out by the fur trade, now common again in the lower bay.
Harbor porpoisePhocoena phocoenaA small, shy porpoise of the bay's inshore waters.
Brown bearUrsus arctosForages on tideflats, sedge meadows and salmon streams.
Black bearUrsus americanusIncludes the rare blue-gray color form known as the glacier bear.
Mountain goatOreamnos americanusWhite specks on the steep cliffs above the fjords.
MooseAlces alcesA relative newcomer that moved into the willow thickets growing on deglaciated land.
Gray wolfCanis lupusPacks range the lower bay and outer coast.
WolverineGulo guloAn elusive traveler of icefields and high ridges.
Hoary marmotMarmota caligataWhistles an alarm from alpine boulder fields.
River otterLontra canadensisOften seen along saltwater shorelines as well as streams.

Birds

Bald eagleHaliaeetus leucocephalusNests in shoreline spruce and patrols beaches for fish.
Tufted puffinFratercula cirrhataNests in burrows on island slopes in the lower bay.
Horned puffinFratercula corniculataA less common puffin that nests in rock crevices.
Kittlitz's murreletBrachyramphus brevirostrisA rare seabird closely tied to glacier-fed waters, and a conservation focus in the park.
Marbled murreletBrachyramphus marmoratusFeeds at sea but can nest on mossy branches of old-growth trees.
Pigeon guillemotCepphus columbaA black seabird with white wing patches and bright red feet.
Black-legged kittiwakeRissa tridactylaGathers in noisy colonies on cliffs near the glaciers.
Common murreUria aalgeNests shoulder to shoulder on narrow cliff ledges.
Pelagic cormorantPhalacrocorax pelagicusA slender, glossy diver of rocky shores.
Arctic ternSterna paradisaeaNests on gravel near the upper bay after wintering in the Southern Ocean.
Harlequin duckHistrionicus histrionicusA boldly patterned duck of surf-splashed shorelines.
Varied thrushIxoreus naeviusIts eerie, single-note whistle drifts through the rainforest.
Rufous hummingbirdSelasphorus rufusArrives in spring as salmonberry and blueberry flower.
Northwestern crowCorvus caurinusA beachcombing crow of Southeast Alaska's shores.

Reptiles & amphibians

Western toadBufo boreasThe park's only amphibian on the checklist, which has colonized ponds formed on land exposed by glacial retreat.

Fish

Sockeye salmonOncorhynchus nerkaSpawns in lakes that formed as the glaciers withdrew.
Coho salmonOncorhynchus kisutchAmong the first salmon to colonize newly formed streams.
Pink salmonOncorhynchus gorbuschaThe most abundant salmon in the park's short coastal streams.
Dolly VardenSalvelinus malmaA char that moves between fresh and salt water.
Pacific halibutHippoglossus stenolepisA huge flatfish of the bay's deep, cold waters.
Pacific herringClupea pallasiiA schooling forage fish vital to whales, seabirds and sea lions.
EulachonThaleichthys pacificusAn oily smelt whose spring runs draw gulls, eagles and sea lions.

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

Climate & When to Visit

Glacier Bay lies in the path of storms sweeping off the Gulf of Alaska, and rain is the rule rather than the exception. Bartlett Cove, near the mouth of the bay, receives about 72.6 inches of precipitation in a typical year, with around 105 inches of snowfall. Low clouds, drizzle and fog are common, but the ocean keeps temperatures moderate in both summer and winter.

Conditions change sharply with distance up the bay. Near the glaciers, cold air flowing down off the ice can bring chilly katabatic winds and noticeably cooler temperatures, while the Fairweather Range squeezes enormous snowfall from passing storms. Summer temperatures generally run from about 50 to 60°F (10 to 15°C). April through June tends to be the driest stretch, and September and October the wettest.

Spring
April through June is usually the driest time of year, with lengthening days, lingering snow on the mountains and the return of humpback whales and migrating birds.
Summer
Mild, cool and often damp, with highs mostly in the 50s and low 60s °F. Long daylight and calmer seas make this the main season for boat tours and kayaking.
Autumn
September and October are typically the wettest months, bringing heavy rain, stronger winds and fall color in the alder and cottonwood.
Winter
Short days, rain at sea level, heavy snow in the mountains and occasional cold outflow winds. Few visitors come and most services close.

Weather hazards

Cold water: Water near the glaciers is barely above freezing, so wear flotation and dress for immersion when paddling.
Calving ice and waves: Falling ice can raise surges and scatter bergs, so keep a wide berth from tidewater glacier faces.
Persistent rain and wind: Waterproof boots, rain gear and warm layers are essential in every month.
Strong tides and currents: Tidal ranges are large, so plan kayak crossings and beach camps with a tide table.
Earthquakes and tsunamis: The park sits on an active fault, so move to high ground if you feel strong shaking near the shore.

Glacier Bay Questions

When is the best time to visit Glacier Bay?

Late May through mid-September is the main season, when tour boats run and whales are present. May and June tend to be drier, while July and August are warmest; bring rain gear no matter when you come.

What is the weather like in Glacier Bay?

Expect cool, cloudy and often rainy weather, with summer temperatures mostly between 50 and 60°F. Air near the glaciers is colder and windier than at Bartlett Cove, so pack a hat, gloves and warm layers even in July.

How fast have Glacier Bay's glaciers retreated?

In 1794 the bay was almost entirely filled with ice. By 1879 the ice had retreated about 48 miles, and by 1916 the Grand Pacific Glacier stood about 65 miles from the bay's mouth, the fastest tidewater glacier retreat on record.

Where can I see whales and other wildlife?

Humpback whales feed in the lower bay and Icy Strait through summer, and Steller sea lions and seabirds crowd South Marble Island. Harbor seals rest on ice floes near Johns Hopkins Glacier, and brown bears and mountain goats are often spotted from the water.

How do glaciers turn into forest here?

Freshly exposed rock is first colonized by mosses, fireweed and mountain-avens. Alder and willow follow and enrich the soil, and eventually Sitka spruce and western hemlock form a full rainforest, a sequence visible as you travel from the head of the bay to its mouth.

What happened at Lituya Bay in 1958?

On July 9, 1958, a powerful earthquake on the Fairweather fault shook loose a huge rockslide into Lituya Bay. The splash wave surged 1,720 feet up the opposite ridge, the highest wave run-up ever recorded.

More parks in the Alaska

← Glacier National Park Grand Canyon National Park →

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