Glacier Bay National Park and Preserve is a national park of the United States located in Southeast Alaska west of Juneau. President Calvin Coolidge proclaimed the area around Glacier Bay a national monument under the Antiquities Act on February 26, 1925. Chapter 8 Subsequent to an expansion of the monument by President Jimmy Carter in 1978, the Alaska National Interest Lands Conservation Act (ANILCA) enlarged the national monument by on December 2, 1980, and created Glacier Bay National Park and Preserve. Title 2, section 202(1). The national preserve encompasses of public land to the immediate northwest of the park, protecting a portion of the Alsek River with its fish and wildlife habitats, while allowing sport hunting.
Glacier Bay became part of a binational UNESCO World Heritage Site in 1979, and was inscribed as a Biosphere Reserve in 1986. The National Park Service undertook an obligation to work with Hoonah and Yakutat Tlingit Native American organizations in the management of the protected area in 1994. The park and preserve cover a total of , with being designated as a wilderness area.
Geology The west side of the bay consists of a 26,000 feet thick sequence of Paleozoic sedimentary rocks, mainly massive limestones and argillite. The oldest rocks in this sequence are the Late Silurian Willoughby limestone and the youngest being the Middle Devonian Black Cap limestone. An outcrop west of Tidal Inlet includes a sandstone, graywacke and limestone of unknown age. Sedimentary rocks of unknown age on the east side of Muir Inlet include tuff interbedded with limestone. The rocks exposed on the 1,205 foot high hill called "The Nunatak" have been metamorphosed. Early Cretaceous diorite stocks are exposed south of Tidal Inlet, and on Sebree and Sturgress Islands. Quartz diorite outcrops on Lemesurier Island. A granitic stock is exposed in Dundas Bay. Mafic dikes up to 20 feet in width occur throughout the area.
Glacial advances occurred 7,000, 5,000 and 500 years ago, with the last extending to the entrance of the bay, where it left a huge semicircular terminal moraine. The consequent surface glacial deposits include gravels as outwash and moraines. Glacial gravels extend up to 2000 feet up the mountain slopes. Lakes have formed where the glaciers have dammed the heads of valleys. Preglacial forests are found east of Goose Cove and on the east side of Muir Inlet. According to Rossman, "One of the outstanding features of the Glacier Bay area is the rapid advance and retreat of the glaciers during several substages within the last few thousand years."
A molybdenite deposit occurs on The Nunatak in quartz veins associated with a quartz monzonite porphyry, which includes gold at 0.04 ounces per ton, and silver at 7.07 ounces per ton. A copper deposit occurs on Observation Mountain. Quartz veins containing gold are exposed west of Dundas Bay and on Gilbert Island. Placer gold is also found in the bay. A silver deposit was mined on the western portion of Rendu Inlet.
According to MacKevett et al., "The most extensive and best gold placer deposits...are in the beach sands near Lituya Bay." Mining of these sands started in 1894, employing up to 200 men by 1896. However, most production had ended by 1917.
The granodiorite and quartz diorite area between Lamplugh Glacier and Reid Glacier contains most of the quartz vein gold lodes, which were produced by six mines. This is known as the Reid Inlet gold area. The Monarch Mines and the Incas Mine was discovered in 1924 by J. Ibach. The Monarch No. 1 and No. 2 veins were drift mined with 200 and 150 foot adits respectively. The LeRoy Mine was the largest, discovered in 1938 by Gustavus founder and resident A.L. Parker and his son L.F. Parker. They operated a two-stamp mill and an aerial tramway until most production had ceased by 1945.
The region experiences tectonic activity with frequent earthquakes. Earthquake-induced landslides have been significant forces for change, inducing tsunamis. Additionally, parts of the region are undergoing post-glacial rebound (also known as isostatic rebound), the process in which land rises after the weight of the glacier has been removed.
Geography
Glacier Bay National Park and Preserve occupies the northernmost section of the southeastern Alaska coastline, between the Gulf of Alaska and Canada. The Canada–US border approaches to within of the ocean in the Saint Elias Mountains at Mount Fairweather, the park's tallest peak at , transitioning to the Fairweather Range from there southwards. The Brady Icefield caps the Fairweather Range on a peninsula extending from the ocean to Glacier Bay, which extends from Icy Strait to the Canada–US border at Grand Pacific Glacier, cutting off the western part of the park. To the east of Glacier Bay the Takhinsha Mountains and the Chilkat Range form a peninsula bounded by the Lynn Canal on the east, with the park's eastern boundary with Tongass National Forest running along the ridgeline. The park's northwestern boundary, which also abuts Tongass National Forest, runs in the valley of the Alsek River to Dry Bay. The preserve lands comprise a small area at Dry Bay — the majority of Glacier Bay lands are national park lands. The park boundary excludes Gustavus at the mouth of Glacier Bay. The lands adjoining the park to the north in Canada are included in Tatshenshini-Alsek Provincial Park.
No roads lead to the park and it is most easily reached by air or sea travel. The Alaska Marine Highway ferry travels between Juneau and Gustavus via the community of Hoonah twice weekly. Despite the lack of roads, the park received an average of about 443,975 recreational visitors annually from 2012 to 2021, with 89,768 visitors in 2021. Most of the visitors arrive via cruise ships. The number of ships that may arrive each day is limited by regulation. Other travelers come on white-water rafting trips, putting in on the Tatshenshini River at Dalton Post in the Yukon Territory and taking out at the Dry Bay Ranger Station in the Glacier Bay National Preserve. Trips generally take six days and pass through Kluane National Park and Reserve in the Yukon and Tatshenshini-Alsek Provincial Park in British Columbia.
Climate
According to the Köppen climate classification system, Glacier Bay National Park has six climate zones; Subarctic With Cool Summers and Year Around Rainfall (Dfc), Subpolar Oceanic (Cfc), Temperate Oceanic (Cfb), Humid Continental Mild Summer Wet All Year (Dfb), Humid Continental Dry Cool Summer (Dsb), and Warm Summer Mediterranean (Csb). The plant hardiness zone at Glacier Bay Visitor Center is 7a with an average annual extreme minimum temperature of 4.2 °F (-15.4 °C).
Environment
Glacier Bay National Park preserves nearly 600,000 acres (2428.1 km2) of federally protected marine ecosystems in Alaska (including submerged lands) against which other less-protected marine ecosystems can be compared. Within the park and preserve there are two Tlingit ancestral homelands that are of cultural and spiritual significance to living communities today. The Alsek River serves as a route of discovery and migration from the coastal mountain range in the park to the Pacific Ocean in the preserve. Within the preserve, in contrast to the park, the Alsek River provides a setting for subsistence uses, commercial fishing, and hunting as provided for in the Alaska National Interest Lands Conservation Act (ANILCA) while simultaneously protecting the glacial ecosystem.
Glaciers The Park is named for its abundant tidewater and terrestrial glaciers, numbering 1,045 in total.
There are seven tidewater glaciers in the park: Margerie Glacier, Grand Pacific Glacier, McBride Glacier, Lamplugh Glacier, Johns Hopkins Glacier, Gilman Glacier, and LaPerouse Glacier. (High tide-water glaciers also include Riggs Glacier, Reid Glacier, Lituya Glacier, and North Crillon Glacier.) Four of these glaciers actively calve icebergs into the bay. In the 1990s, the Muir Glacier receded to the point that it was no longer a tidewater glacier. The advance and recession of the park's glaciers has been extensively documented since La Perouse visited the bay in 1786. According to the U.S. National Park Service, "In general, tidewater and terrestrial glaciers in the Park have been thinning and slowly receding over the last several decades." Some glaciers continue to advance, including Johns Hopkins Glacier and glaciers in Lituya Bay.
Glacial retreat Joseph Whidbey, master of the Discovery during the 1791–95 Vancouver expedition, found Icy Strait, at the south end of Glacier Bay, choked with ice in 1794. Glacier Bay itself was almost entirely covered by one large tidewater glacier. In 1879 naturalist John Muir found that the ice had retreated almost all the way up the bay, a distance of around . By 1916 the Grand Pacific Glacier was at the head of Tarr Inlet about 65 miles (105 km) from Glacier Bay's mouth. This is the fastest documented glacier retreat. Not all of the park's glaciers are in retreat. Two examples are the Johns Hopkins Glacier which, according to observations in 2012, has been advancing at the rate of per day, and the Margerie Glacier which is stable, neither advancing nor retreating. Scientists working in the park and preserve hope to learn how glacial activity relates to climate change.
Ecosystems Wet tundra along with Sitka spruce and Western hemlock forests are mainly found in the Lower bay. In the Upper bay there are tidewater glaciers and from the newly deglaciated land are the post-glacial meadows. In the peaks of Glacier Bay are Alpine tundra, glaciers and ice fields.
Regions of the park closest to the Gulf of Alaska have a relatively mild climate with significant rainfall and comparatively low snowfall. Lower Glacier Bay is a transitional zone, and upper Glacier Bay is cold and snowy. Access to the land can be difficult, since the glacial fjords have steep walls that rise directly from the water. Where there are shoreline flats, they can be densely vegetated with alder and devils club, making hiking difficult.
Fauna Wildlife in Glacier Bay includes both brown and black bears, along with gray wolves, coyotes, moose, black-tailed deer, red foxes, porcupines, marmots, beavers, lynxes, two species of otters, minks, wolverines, and mountain goats. Birds that nest in this park include the bald eagles, golden eagles, five species of woodpecker, two species of hummingbird, ravens, four species of falcons, six species of hawk, ospreys, and ten species of owl. Marine mammal species that swim offshore are the sea otter, harbor seal, Steller sea lion, harbor porpoise, orca, minke whale, and humpback whale.
Activities
About 80% of visitors to Glacier Bay arrive on cruise ships. The National Park Service operates cooperative programs where rangers provide interpretive services aboard the ships and on the smaller boats that offer excursion trips to more distant park features. In-park accommodations are available at the Glacier Bay Lodge.Catton, Ch. 8 The park and preserve hosts many outdoor activities such as hiking, camping, mountaineering, kayaking, rafting, fishing, and bird-watching. Unlike many other national parks in Alaska, subsistence hunting is not allowed in the park, only in the preserve.