Glacier Bay National Park and Preserve is a national park in the United States located in Southeast Alaska, west of Juneau. President Calvin Coolidge declared the area around Glacier Bay a national monument under the Antiquities Act on February 26, 1925. After President Jimmy Carter expanded the monument in 1978, the Alaska National Interest Lands Conservation Act (ANILCA) increased the monument by 523,000 acres (817.2 square miles; 2,116.5 square kilometers) on December 2, 1980. This action also created Glacier Bay National Park and Preserve. The national preserve covers 58,406 acres (91.3 square miles; 236.4 square kilometers) of public land to the northwest of the park. It protects part of the Alsek River, including its fish and wildlife habitats, and allows sport hunting.

Glacier Bay became part of a binational UNESCO World Heritage Site in 1979 and was added to the list of Biosphere Reserves in 1986. In 1994, the National Park Service agreed to work with Hoonah and Yakutat Tlingit Native American groups to help manage the protected area. Together, the park and preserve cover 3,223,384 acres (5,037 square miles; 13,045 square kilometers). Of this, 2,770,000 acres (4,328 square miles; 11,210 square kilometers) are designated as a wilderness area.

Geology

The west side of the bay has a thick layer of Paleozoic sedimentary rocks. These rocks are mainly massive limestones and argillite. The oldest rocks in this layer are the Late Silurian Willoughby limestone, and the youngest are the Middle Devonian Black Cap limestone. An outcrop west of Tidal Inlet includes sandstone, graywacke, and limestone of unknown age. Sedimentary rocks of unknown age on the east side of Muir Inlet include tuff mixed with limestone. The rocks exposed on the 1,205-foot-high hill called "The Nunatak" have been changed by heat and pressure. Early Cretaceous diorite rocks are found south of Tidal Inlet and on Sebree and Sturgress Islands. Quartz diorite appears on Lemesurier Island. A granitic rock is exposed in Dundas Bay. Mafic dikes, up to 20 feet wide, are found throughout the area.

Glaciers moved into the area 7,000, 5,000, and 500 years ago. The last glacier reached the entrance of the bay, leaving a large semicircular terminal moraine. Surface deposits from glaciers include gravels as outwash and moraines. Glacial gravels extend up to 2,000 feet up mountain slopes. Lakes formed where glaciers blocked 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 is found on The Nunatak in quartz veins linked to quartz monzonite porphyry, which contains 0.04 ounces of gold per ton and 7.07 ounces of silver per ton. A copper deposit is found on Observation Mountain. Quartz veins with 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 part 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 began in 1894, employing up to 200 men by 1896. However, most production 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 mined by six mines. This is known as the Reid Inlet gold area. The Monarch Mines and the Incas Mine were discovered in 1924 by J. Ibach. The Monarch No. 1 and No. 2 veins were mined by digging tunnels with 200- and 150-foot-long tunnels, 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 ended by 1945.

The region experiences frequent earthquakes due to tectonic activity. Earthquake-induced landslides have caused significant changes and triggered tsunamis. Parts of the region are also rising due to post-glacial rebound, a process where land rises after glaciers melt.

Geography

Glacier Bay National Park and Preserve is located in the northern part of the southeastern Alaska coastline, between the Gulf of Alaska and Canada. The Canada–US border comes within 15 miles (24 km) of the ocean in the Saint Elias Mountains at Mount Fairweather, the park's tallest peak at 15,300 feet (4,700 m). From there, the border changes into the Fairweather Range. The Brady Icefield covers the Fairweather Range on a peninsula that extends from the ocean to Glacier Bay. Glacier Bay stretches from Icy Strait to the Canada–US border at Grand Pacific Glacier, separating the western part of the park. To the east of Glacier Bay, the Takhinsha Mountains and the Chilkat Range form a peninsula bordered by the Lynn Canal on the east. The park’s eastern boundary with Tongass National Forest follows the ridgeline of these mountains. The park’s northwestern boundary, which also borders Tongass National Forest, runs through the valley of the Alsek River to Dry Bay. The preserve includes a small area at Dry Bay, while most of Glacier Bay is part of the national park. The park boundary does not include Gustavus, a town at the mouth of Glacier Bay. Lands north of the park in Canada are part of Tatshenshini-Alsek Provincial Park.

There are no roads to the park, and it is best reached by air or sea travel. The Alaska Marine Highway ferry travels between Juneau and Gustavus, stopping at Hoonah twice weekly. From 2012 to 2021, the park had about 443,975 visitors each year on average, with 89,768 visitors in 2021. Most visitors arrive by cruise ship. Regulations limit the number of ships that can arrive each day. Other visitors travel by white-water rafting trips, starting at Dalton Post on the Tatshenshini River in the Yukon Territory and ending at the Dry Bay Ranger Station in the Glacier Bay National Preserve. These trips usually 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 system, Glacier Bay National Park has six climate zones: Subarctic with cool summers and rain all year (Dfc), Subpolar Oceanic (Cfc), Temperate Oceanic (Cfb), Humid Continental with mild summer and year-round rain (Dfb), Humid Continental with dry, cool summer (Dsb), and Warm Summer Mediterranean (Csb). The plant hardiness zone at Glacier Bay Visitor Center is 7a, with an average lowest temperature of 4.2 °F (-15.4 °C).

Environment

Glacier Bay National Park protects nearly 600,000 acres (about 2,428 square kilometers) of marine ecosystems in Alaska, including underwater areas. These protected areas help scientists compare them to less-protected marine ecosystems. Within the park and preserve, there are two Tlingit ancestral homelands that are important to living communities today. The Alsek River connects the coastal mountain range in the park to the Pacific Ocean in the preserve. In the preserve, the Alsek River supports activities like subsistence hunting, fishing, and hunting, as allowed by the Alaska National Interest Lands Conservation Act (ANILCA), while also protecting glacial ecosystems.

The park is named for its many glaciers, including 1,045 glaciers total. Seven of these are tidewater glaciers: Margerie, Grand Pacific, McBride, Lamplugh, Johns Hopkins, Gilman, and LaPerouse. Other tidewater glaciers include Riggs, Reid, Lituya, and North Crillon. Four of these glaciers regularly calve icebergs into the bay. In the 1990s, Muir Glacier receded so much it was no longer a tidewater glacier. Scientists have recorded changes in the park’s glaciers since 1786, when explorer La Perouse visited. According to the U.S. National Park Service, most glaciers in the park have been thinning and slowly moving backward over recent decades. Some glaciers, like Johns Hopkins and those in Lituya Bay, are still moving forward.

In 1794, Joseph Whidbey, who sailed with the Vancouver expedition, found Icy Strait near Glacier Bay filled with ice. At that time, Glacier Bay was almost completely covered by one large tidewater glacier. By 1879, naturalist John Muir observed that the glacier had retreated about 48 miles (77 kilometers) up the bay. By 1916, the Grand Pacific Glacier had moved 65 miles (105 kilometers) from the mouth of Glacier Bay, marking the fastest glacier retreat ever recorded. Not all glaciers are retreating. For example, Johns Hopkins Glacier has advanced 10 to 15 feet (3 to 4.6 meters) daily since 2012, and Margerie Glacier has remained stable. Scientists study these changes to understand how glaciers relate to climate change.

Wet tundra, Sitka spruce, and Western hemlock forests are common in the Lower Bay. In the Upper Bay, tidewater glaciers and newly exposed land support post-glacial meadows. Alpine tundra, glaciers, and ice fields are found in the mountain peaks of Glacier Bay.

Areas near the Gulf of Alaska have mild weather with heavy rainfall and little snow. Lower Glacier Bay is a transitional zone, while Upper Glacier Bay is cold and snowy. Access to land is difficult because glacial fjords have steep walls rising directly from the water. Shoreline flats may be densely covered with alder and devil’s club, making hiking challenging.

Wildlife in Glacier Bay includes brown and black bears, timber wolves, coyotes, moose, black-tailed deer, red foxes, porcupines, marmots, beavers, Canadian lynx, two otter species, mink, wolverines, and mountain goats. Birds nesting in the park include bald eagles, golden eagles, five woodpecker species, two hummingbird species, ravens, four falcon species, six hawk species, ospreys, and ten owl species. Marine mammals near the shore include sea otters, harbor seals, Steller sea lions, harbor porpoises, orcas, minke whales, and humpback whales.

• Glacier Bay Geologic Column
• Map of Maximum Glacial Extent
• Nunatak Molybdenite Location
• Brady Nunatak Nickel-Copper Geological Map
• Fairweather Fault Geological Map
• Fairweather Fault Geological Map Legend

Activities

About 80% of visitors to Glacier Bay arrive on cruise ships. The National Park Service works with rangers to provide educational services on cruise ships and smaller boats that take visitors to farther parts of the park. Visitors can stay overnight at the Glacier Bay Lodge inside the park. The park and preserve offer many outdoor activities, including hiking, camping, mountaineering, kayaking, rafting, fishing, and bird-watching. Unlike other national parks in Alaska, subsistence hunting (hunting for food and survival) is not allowed in the park, only in the preserve.

Sport hunting and trapping are allowed in the preserve. To hunt or trap, people must have the correct licenses and permits and follow all state rules. The National Park Service and the State of Alaska work together to manage wildlife in the preserve. People who camp or hunt should know that brown bears are common in the preserve and should be ready to avoid conflicts with them. Animals typically hunted in the preserve include black bears, mountain goats, wolves, wolverines, snowshoe hares, ptarmigans, waterfowl, and many fur-bearing animals. One hunting guide is allowed to operate in the preserve through a special agreement. Three lodges and one outfitter can help with transportation and services for fishing and hunting small animals and waterfowl.

Sport fishing is also popular in the park. Deep-sea fishers often catch halibut, and rivers and lakes have Dolly Varden and rainbow trout for fishing. Anyone 16 or older who is not an Alaska resident must have an Alaskan sportfishing license to fish in Alaska’s fresh and salt waters. Residents aged 16–59 also need a license to fish in Alaska’s waters.

The park has limited trails near Bartlett Cove, including the Forest Loop Trail (1 mile) and Bartlett River Trail (4 miles round trip). The Beach Trail runs 6 miles along the coastline. Beyond these trails, experienced hikers can explore the backcountry. Hikers should be prepared for wet weather and carry bear spray because brown bears are common in the area.

Human history

The earliest signs of people living in Glacier Bay date back about 10,000 years ago. Some archaeological sites near the park from that time have been found. However, evidence of human activity is limited because much of the area was covered by glaciers for long periods, and moving glaciers may have removed all signs of people living there. As the land continues to rise, new sites that were once underwater might be discovered. Most of the archaeological evidence found so far is from the last 200 years. The Haida, Eyak, and Tlingit peoples may have lived along the coast until historical times, when the Tlingit became the main group in the area.

In 1786, Jean-François de Galaup, comte de Lapérouse, was the first European to explore the Alaskan coast on foot near Glacier Bay. He arrived in Lituya Bay and met with the Tlingit people. Russian fur traders likely visited the area in the mid-1700s. Later, George Vancouver visited the region in 1794 during his expedition. He and his team saw the glaciers at their largest size, which matched the time of their visit. Russians were the main people interested in the area until the 1880s, when Americans came to Alaska and the Klondike because of the gold rush in the 1890s.

John Muir visited Glacier Bay in 1879, just before Yosemite National Park was created. He went to Alaska to study glaciers and learn about how the landscape of Yosemite Valley was formed. Muir wrote about his trips in the San Francisco Bulletin and later collected his writings into a book called Travels in Alaska, which promoted Glacier Bay and the Inside Passage. His work led to the glacier near Glacier Bay being named Muir Glacier, which was once about 300 feet tall at the water’s edge and the most active glacier in the area.

In the 1890s, the Pacific Coast Steamship Company offered tours up the Inside Passage from Tacoma and Portland, showing visitors Muir Glacier and Glacier Bay. The area became popular with scientists and geologists who studied and named the glaciers. In 1899, Edward Harriman organized the Harriman Alaska Expedition, which included Muir, a photographer, and others. They spent five days at Glacier Bay and noticed that the glaciers were retreating. A few months later, an earthquake in 1899 caused Muir Glacier to collapse into the bay, making it less accessible for tourists. After 1900, Taku Glacier became a popular place to visit. A salmon cannery was built in 1900 at Dundas Bay and operated until 1931, employing workers from Native, white, and Chinese backgrounds.

Muir’s writings caught the attention of William Skinner Cooper, an ecologist who wanted to study how plants grow on land exposed by retreating glaciers. Cooper visited Glacier Bay in 1916 and set up nine test plots to monitor plant growth in future visits. He returned in 1922 and wrote a paper suggesting Glacier Bay be protected as a national monument. The Ecological Society of America supported this idea and sent letters to President Calvin Coolidge, the National Park Service, and others. However, the U.S. Geological Survey opposed the plan, saying the area had potential for mining. The Interior Department sent George Alexander Parks to study the area, and his report recommended a small boundary that included only glaciers. Cooper and the Ecological Society then wrote letters to support the National Park Service, leading Coolidge to expand the park’s boundaries to include some forests. Coolidge officially created Glacier Bay National Monument on February 26, 1925, using the Antiquities Act.

In the 1920s, Alaska’s game managers faced criticism for not protecting brown bears. The state proposed expanding the monument’s boundaries using land from the Tongass National Forest as a bear sanctuary. The Park Service agreed, and the Forest Service preferred expanding Glacier Bay over creating a national park on Admiralty Island. In the 1930s, Ernest Gruening, a future governor of Alaska, suggested protecting the entire region, including the Saint Elias and Wrangell Ranges. This idea was not realized until 1978, when Wrangell-St. Elias National Monument was created. Instead, the area was expanded eastward for bear habitat and westward to protect the Gulf of Alaska coastline. President Franklin D. Roosevelt used the Antiquities Act in 1939 to expand the monument, making it the largest unit in the national park system at the time.

During World War II, the U.S. Army used land near Excursion Inlet as a logistics base for moving supplies through the Inside Passage. They also built an airfield at Gustavus, which was too late to help in the Aleutian Campaign but was suitable for B-29 planes. In 1955, the area around Gustavus and Excursion Inlet was returned to public use.

No Park Service workers were assigned to the monument until 1949, when a seasonal ranger was stationed at Bartlett Cove. From 1953 onward, the monument was managed locally. In the 1950s, the Park Service expanded facilities at Bartlett Cove and built an administrative site at Indian Point. The Glacier Bay Lodge opened in 1966, and cruise ships began visiting regularly in 1969.

In 1958, surveyors found copper and nickel deposits under the Brady Icefield. A mining company proposed building a mine under the icefield, using a law from 1936 that allowed mining in the monument. In response, Senator Lee Metcalf introduced the Mining in the Parks Act to stop mining in Glacier Bay and five other parks and monuments.

World Heritage Site

The Kluane-Wrangell-St. Elias-Glacier Bay-Tatshenshini-Alsek transborder park system, which includes Kluane, Wrangell-St. Elias, Glacier Bay, and Tatshenshini-Alsek parks, was named a UNESCO World Heritage Site in 1979. This recognition was due to the beautiful glaciers and icefields, as well as the area's importance as a home for grizzly bears, caribou, and Dall sheep. Glacier Bay National Park was added to the Heritage Site in 1992.