General · EdgepediaSeptember 17, 20267 min read

Glacier Bay National Park and Preserve

Glacier Bay National Park and Preserve is a 3,280,840-acre (5,126 square mile) unit of the United States National Park System in southeastern Alaska, protecting a fjord system carved by tidewater glaciers, the Fairweather Mountains, and the largest marine area managed by the National Park Service. It was proclaimed a national monument on February 26, 1925, and redesignated a national park and preserve on December 2, 1980, under the Alaska National Interest Lands Conservation Act (ANILCA).¹

Key fact	Detail
Established	National monument February 26, 1925; national park and preserve December 2, 1980¹
Area	Park 3,222,434 acres (5,035 sq mi); preserve 58,406 acres (91 sq mi); total 3,280,840 acres, roughly the size of Connecticut¹
Glaciers	1,059 glaciers at last count; 62 named, 7 of them active tidewater glaciers that calve icebergs into the sea; ice covers 1,571 square miles, 30.6 percent of the park¹
Glacial retreat	A single tidewater glacier filled the bay about 250 years ago; retreat began by 1750 and the ice has withdrawn 60 miles to the head of the bay¹
International designations	World Biosphere Reserve 1986; World Heritage Site 1992¹
Marine waters	607,100 acres, the largest marine area managed by the National Park Service; deepest point in the bay 1,427 feet below sea level¹
Visitation (2024)	691,387 cruise ship passengers, 13,516 tour vessel passengers, 13,748 lodge guests; daily vessel limits of 2 cruise ships, 3 tour vessels, 6 charter vessels, and 25 private vessels¹

Establishment and protection history

The monument proclamation of February 1925 followed a campaign organized by the Ecological Society of America, led by the ecologist William S. Cooper, who wanted to preserve the bay not only for its glaciers and wildlife but as a living laboratory for study.²^•³ Scientists had been interested in the bay since 1879, when the naturalist John Muir made the first of several visits.⁴ President Calvin Coolidge proclaimed the monument in February 1925.²

Congress redesignated the area as Glacier Bay National Park and Preserve on December 2, 1980, as part of the Alaska lands act, which added some 47 million acres to the national park system in that year.¹^•⁵ Earlier, President Dwight Eisenhower had diminished the monument by proclamation, one of six monuments he reduced; the area later became a national park.⁶

Layered international designations followed. In 1986 the area joined the Glacier Bay-Admiralty Island Biosphere Reserve under UNESCO's Man and the Biosphere Programme, a reserve of 3,455,290 hectares combining Glacier Bay with Admiralty Island and a marine corridor between them.¹^•⁷ In 1992 Glacier Bay became part of the Kluane / Wrangell-St. Elias / Glacier Bay / Tatshenshini-Alsek World Heritage Site, a 9,839,121-hectare property along the Canada–United States boundary that contains the largest non-polar icefield in the world.⁸

Glacial retreat and the natural laboratory

Glacier Bay's defining feature is its documented retreat. About 250 years ago a single large tidewater glacier, thousands of feet thick, filled what is now a 65-mile-long fjord; the Little Ice Age advance reached its maximum here around 1750, when general melting began.¹^•⁹ A United States Geological Survey assessment records that the main trunk glaciers retreated about 120 km from Icy Strait to the head of the bay's west arm in just 180 years, which it ranks as the fastest and most prolonged historic tidewater calving retreat in Alaska.¹⁰ Three centuries of maps and accounts of glacier positions have supported research on glacial sedimentology, post-ice ecological change, and landslide hazards.¹¹

The retreat follows the tidewater glacier cycle: once a calving glacier pulls back from its terminal moraine shoal into deep water, it becomes unstable and retreats catastrophically, largely independent of climate.¹⁰ Today the park holds 1,059 glaciers, of which 62 are named and 7 are active tidewater glaciers calving into the sea. Most large glaciers originate between 8,000 and 15,000 feet of elevation, and the Brady, Grand Pacific, and Carroll glaciers each cover more than 100 square miles.¹

Current trends. In general, tidewater and terrestrial glaciers in the park have been thinning and receding for decades.¹ Recent research found 11 percent less glacial ice in Glacier Bay than in the 1950s, and of the more than 100,000 glaciers in Alaska, 95 percent are currently thinning, stagnating, or retreating, with the rate of thinning increasing. Heavy snowfall in the Fairweather Mountains, where over 100 feet of snow may fall annually, keeps a few of the park's glaciers stable.⁹ Individual glaciers differ: Johns Hopkins Glacier is thinning but advancing, while Grand Pacific and Margerie are receding.¹

The exposed land hosts a succession of marine and terrestrial life, from pioneer lichens, moss, alder, and cottonwood near the ice to mature forests of western hemlock and Sitka spruce farther out, making the area a natural setting for studying plant succession and animal recolonization after glacial retreat.⁷

Landscape, climate, and wildlife

The park spans from the deepest glacial fjord to the summit of Mount Fairweather, at 15,300 feet the tallest mountain in the park; other major peaks include Mount Quincy Adams (13,650 feet) and Mount Crillon (12,726 feet).³^•¹ The bay reaches 1,427 feet below sea level, and its tides are mixed semi-diurnal, with a maximum tidal change of about 22.5 feet from high to low.¹

Glacier Bay sits at the northern end of the Tongass, the largest temperate rainforest in the world. Summer temperatures run 50 to 60 degrees Fahrenheit and winter 20 to 30 degrees, with extremes of -10 degrees; some form of precipitation falls on average 228 days a year, totaling 70 to 80 inches including 14 feet of snow.¹ Major earthquakes in the last 150 years include events of magnitude 8.2 in 1899, 7.8 in 1958, and 6.3 in 2017.¹

Documented biodiversity includes 329 fish species, 247 bird species, 12 marine and 34 terrestrial mammal species, one amphibian (the boreal toad), one reptile (the leatherback sea turtle), and 594 vascular plant taxa.¹ Humpback whales converge on the bay's rich feeding grounds in summer and range elsewhere to breed in winter.¹^•¹²

Homeland and co-stewardship

Glacier Bay is the ancestral homeland of the Huna and Yakutat Lingít (Tlingit), who have lived there since time immemorial. Many Huna Łingít today live across Icy Strait in the village of Hoonah, and the bay remains central to their stories, songs, dances, and traditional practices. Park management is committed to working in collaboration with Lingít tribes to promote co-stewardship, and the Xunaa Shuká Hít (Huna Tribal House), commemorated in 2016, stands on the shoreline at Bartlett Cove as a place of reconnection.¹^•³

Visiting

There are no roads that lead directly to the park. Headquarters, the visitor center, and Glacier Bay Lodge sit at Bartlett Cove, 10 miles by road from the small town of Gustavus, which lies about 65 miles northwest of Juneau. From May through September, access comes by scheduled and charter air service, Alaska Marine Highway ferries, cruise ships, tour boats, and charter boats, with more than 50 companies providing access.¹²

Most visitors, over 90 percent, arrive by cruise ship or tour boat and never step foot on land in the park.¹ The National Park Service limits marine vessels each summer day to two cruise ships, three tour vessels, six charter vessels, and 25 private vessels, and private boats entering the bay from June through August need a free permit, reservable up to 60 days in advance.¹^•¹² On land, the park offers about 15.5 miles of hiking trails, over 700 miles of shoreline to kayak and camp, a 48-room lodge, and a 33-site campground at Bartlett Cove.¹

Visitation is growing and lengthening. 2024 marked the second consecutive record-breaking visitation year.¹ Cruise ship passengers of all sizes in Glacier Bay increased by nearly 50 percent since 2013, and the visitor season now extends from late April through mid-October, a marked change from 20 years ago when ships were rarely seen before May 1 and never after early September; in 2023 the bay recorded 8,389 cruise ship passengers in April and 43,922 visitors in October.¹³

References

Initially written Sep 17, 2026 · Reviewed: Oct 21, 2026 · Edited: Oct 15, 2026; Oct 21, 2026