Denali National Park and Preserve

Prehistory and protohistory Human habitation in the Denali Region extends back more than 11,000 years, with documented sites just outside the park boundaries dating back more than 8,000 years. However, relatively few archaeological sites have been documented within the park boundaries, owing to the region's high elevation, harsh winter conditions, and scarce resources compared to lower elevations. The oldest site within park boundaries is the Teklanika River site, dated to about 7130 BC. More than 84 archaeological sites have been documented within the park. The sites are typically characterized as hunting camps rather than settlements and provide little cultural context. The presence of Athabaskan peoples in the region is dated to 1,500 - 1,000 years before present on linguistic and archaeological evidence, while researchers have proposed that Athabaskans may have inhabited the area for thousands of years before then. The principal groups in the park area in the last 500 years include the Koyukon, Tanana, and Dena'ina people. Establishment of the park In 1906, conservationist Charles Alexander Sheldon proposed preserving the Denali region as a national park. He presented the plan to his co-members of the Boone and Crockett Club. They decided that the political climate at the time was unfavorable for congressional action and that the best hope of success rested on the approval and support of the Alaskans themselves. Sheldon wrote, "The first step was to secure the approval and cooperation of the delegate who represented Alaska in Congress." In October 1915, Sheldon took up the matter with E. W. Nelson of the Biological Survey at Washington, D.C., and with George Bird Grinnell, to introduce a suitable bill in the coming session of Congress. The matter was then presented to the Game Committee of the Boone and Crockett Club and, after a full discussion, the committee endorsed it. On December 3, 1915, the plan was presented to Alaska's delegate, James Wickersham, who, after some deliberation, gave his approval. The plan was then presented to the executive committee of the Boone and Crockett Club and, on December 15, 1915, was unanimously accepted. The plan was thereupon endorsed by the club and presented to Stephen Mather, Assistant Secretary of the Interior in Washington, D.C., who immediately approved it. The bill was introduced in April 1916 by Delegate Wickersham in the House and by Senator Key Pittman of Nevada in the Senate. Much lobbying took place the following year, and on February 19, 1917, the bill passed. On February 26, 1917, 11 years after its conception, the bill was signed into law by President Woodrow Wilson, thereby creating Mount McKinley National Park. A portion of Denali, excluding the summit, was included in the original park boundary. The boundary was expanded in 1922 and again in 1932 and 1947 to include the area of the hotel and railroad. On Thanksgiving Day in 1921, the Mount McKinley Park Hotel opened. In July 1923, President Warren Harding stopped at the hotel, on a tour of the length of the Alaska Railroad, during which he drove a golden spike signaling its completion at Nenana. The hotel was the first thing visitors saw stepping down from the train. The flat-roofed, two-story log building featured exposed balconies, glass windows, and electric lights. Inside were two dozen guest rooms, a shop, a lunch counter, a kitchen, and a storeroom. By the 1930s, there were reports of lice, dirty linen, drafty rooms, and marginal food, which led to the hotel eventually closing. After being abandoned for many years, the hotel was destroyed in 1972 by a fire. The Park Road was completed in 1938 after 17 years of construction. In 1967, the park was the site of one of the deadliest mountaineering accidents in the United States with the Mount McKinley disaster, where seven climbers died in an intense blizzard on Denali. The Park Service debated closing the mountain to climbing in the wake of the accident, but ultimately decided to keep it open. The park was designated an international biosphere reserve in 1976. In 1980, Mount McKinley National Park was combined with Denali National Monument, and the Alaska National Interest Lands Conservation Act named the combined unit the Denali National Park and Preserve. At that time, the Alaska State Board of Geographic Names changed the mountain's name to Denali. However, the U.S. Board on Geographic Names did not recognize the change and continued to use the official name, Mount McKinley. This situation lasted until August 30, 2015, when President Barack Obama directed Secretary of the Interior Sally Jewell to rename the mountain to Denali, using statutory authority to act on requests when the Board of Geographic Names does not do so in a "reasonable" period. At the beginning of his second term, President Donald Trump signed an executive order to revert the name of the mountain to Mount McKinley, while explicitly leaving the name of the national park and preserve unchanged. Renaming the park requires an act of Congress. Recent decades In 1992, Christopher McCandless ventured into the Alaskan wilderness and settled in an abandoned bus in the park on the Stampede Trail at , near Lake Wentitika. He carried little food or equipment and hoped to live for a time in solitude. Almost four months later, McCandless's starved remains were found, weighing only . His story has been widely publicized via articles, books, and films, and the bus where his remains were found has become a shrine attracting people from around the world. On November 5, 2012, the United States Mint released the 15th coin of its America the Beautiful Quarters series, which honors Denali National Park. The coin's reverse features a Dall sheep against a background of Denali. In September 2013, President Barack Obama signed the Denali National Park Improvement Act into law. The statute allows the United States Department of the Interior to "issue permits for microhydroelectric projects in the Kantishna Hills area of the Denali National Park and Preserve in Alaska"; it authorizes the Department of the Interior and a company called Doyon Tourism, Inc. to exchange some land in the area; it authorizes the National Park Service (NPS) to "issue permits to construct a natural gas pipeline in the Denali National Park"; and it renames the existing Talkeetna Ranger Station the Walter Harper Talkeetna Ranger Station. The National Parks Conservation Association supported the bill because the legislation "takes a thoughtful approach to protecting roadless Alaska, promoting renewable energy development, and honoring native Alaskans". On September 24, 2020, the Museum of The North at the University of Alaska (Fairbanks) announced it became the permanent home of McCandless's 'Magic Bus 142' where it will be restored and an outdoor exhibit will be created. ==Geography==

Denali National Park and Preserve includes the central, highest portion of the Alaska Range, along with many glaciers and glacial valleys that flow southward out of the range. To the north, the park and preserve encompass the valleys of the McKinley, Toklat, and Foraker Rivers, as well as the Kantishna and Wyoming Hills. The George Parks Highway runs along the eastern edge of the park, crossing the Alaska Range at the divide between the valleys of the Chultina River and the Nenana River. The entrance to the park is about south of Healy. The Denali Visitor Center and the park headquarters are located just inside the entrance. Preserve lands are located on the west side of the park, with one parcel encompassing areas of lakes in the Highpower Creek and Muddy River areas, and the second preserve area covering the southwest end of the Alaska Range around Mount Dall. In contrast to the park, where hunting is prohibited or restricted to subsistence hunting by residents, sport hunting is allowed in the preserve lands. Nikolai, Telida, Lake Minchumina, and Cantwell residents are authorized to hunt inside the park because large portions of these communities historically hunted in the area for subsistence purposes. The size and relative isolation of Denali lead it to generate its own weather. As a consequence, clouds often surround it. An additional estimate is that only 10 percent of visitors get to see the mountain unobscured from top to bottom.--> The Eielson Visitor Center has an etched outline of the peaks of Denali on the window facing the Denali that shows where the mountain would be if it were visible. Wilderness The Denali Wilderness is a wilderness area within Denali National Park that protects the higher elevations of the central Alaska Range, including Denali, federally designated as Mount McKinley. The wilderness comprises about one-third of the current national park and preserve——which corresponds to the former park boundaries before 1980. ==Geology==

history Denali National Park and Preserve is located in the central Alaska Range, a mountain chain extending across Alaska. Its best-known geologic feature is Denali, federally designated as Mount McKinley. Its elevation of makes it the highest mountain in North America. Its vertical relief (distance from base to peak) of is the highest of any mountain in the world. The mountain is still gaining about in height each year due to the continued convergence of the North American and Pacific Plates. The mountain is primarily made of granite, a hard rock that does not erode easily; this is why it has retained such a great height rather than being eroded. The park area is characterized by collision tectonics: over the past millions of years, exotic terranes in the Pacific Ocean have been moving toward the North American landmass and accreting, or attaching, to the area that now makes up Alaska. The oldest rocks in the park are part of the Yukon-Tanana terrane. They originated from ocean sediments deposited between 400 million and 1 billion years ago. The original rocks have been affected by regional metamorphism, folding, and faulting, forming rocks such as schist, quartzite, phyllite, slate, marble, and limestone. The next oldest group of rocks is the Farewell terrane. It is composed of rocks from the Paleozoic era (250–500 million years old). The sediments that make up these rocks were deposited in a variety of marine environments, ranging from deep-ocean basins to continental shelves. The abundant marine fossils are evidence that around 380 million years ago, this area had a warm, tropical climate. The Pingston, McKinley, and Chulitna terranes are the next-oldest; they were deposited during the Mesozoic era. The rock types include marble, chert, limestone, shale, and sandstone. There are intrusions of igneous rocks, such as gabbro, diabase, and diorite. Special features include pillow basalts, which are formed when molten lava flows into water and a hard outer crust forms, making a puffy, pillow-shaped feature; as well as an ophiolite sequence, which is a distinct sequence of rocks indicating that a section of the oceanic crust has been uplifted and thrust onto a continental area. Some of the youngest rocks in the park include the Kahiltna terrane, a flysch sequence (a sedimentary rock sequence deposited in a marine environment during the early stages of mountain building) formed about 100 million years ago during late Cretaceous time. Another rock sequence is the McKinley Intrusive Sequence, which includes Denali. The Cantwell Volcanics include basalt and rhyolite flows, as well as ash deposits. An example can be seen at Polychrome Pass in the park. Mesozoic fossils include fossil trackways from therizinosaurids and hadrosaurids in the Cantwell Formation indicate the area was once an immigration point for dinosaurs traveling between Asia and North America during the Late Cretaceous period. Studies of fossil plants from the same formation indicate the area was wet, with marshes and ponds throughout the region. Denali National Park and Preserve are located in an area of intense tectonic activity: the Pacific Plate is subducting under the North American Plate, creating the Denali Fault system, which is a right-lateral strike-slip fault over long. This is a part of the larger fault system, which includes the famous San Andreas Fault of California. Over 600 earthquakes occur in the park each year, helping seismologists to understand this fault system. Most of these earthquakes are too small to be felt, though two large earthquakes occurred in 2002. On October 23, 2002, a magnitude 6.7 earthquake occurred in the park, and on November 3, 2002, a magnitude 7.9 earthquake occurred. These earthquakes did not cause a significant loss of life or property, since the area is very sparsely populated, but they did trigger thousands of landslides. Glaciers in the southwestern portion of the preserve Glaciers cover about 16% of the 6 million acres of Denali National Park and Preserve. Measurements indicate that glaciers in the park are losing about 6.6 ft (2 m) of vertical water equivalent each year. There are more extensive glaciers on the southeastern side of the range because more snow is dropped on this side from the moisture-bearing winds from the Gulf of Alaska. The 5 largest south-facing glaciers are Yentna ( long), Kahiltna (), Tokositna (), Ruth (), and Eldrige (). Permafrost Permanently frozen ground is known as permafrost. The permafrost is discontinuous in Denali due to differences in vegetation, temperatures, snow cover, and hydrology. The active layer freezing and thawing seasonally can be from 1 inch (25 mm) to 10 feet (3.0 m) thick. The permafrost layer is located between 30 and 100 feet (9.1 and 30.5 m) below the active layer. A stand of oddly leaning white spruce growing on a lower slope of Denali is called the Drunken Forest. The trees lean due to soil sliding caused by permafrost freeze-thaw cycles. Permafrost impacts the park's ecosystem by influencing hydrology, vegetation patterns, and wildlife. During the very cold Pleistocene climates, all of Denali was solidly frozen. The northern areas of the range are still frozen due to continued cold temperatures. About 75% of Denali had near-surface permafrost, or an active permafrost layer, in the 1950s. In the 2000s, around 50% of Denali had near-surface permafrost. It is suspected that by the 2050s, only about 6% of surface permafrost will remain. Permafrost thaw causes landslides as the ice-rich soil transforms into mud slurry. Landslides have previously impacted accessibility in Denali by obstructing the roads in the park. Permafrost thaw releases additional carbon into the atmosphere. Shallow ponds in Denali are known as thaw lakes and cave-in lakes, formed when sun-warmed water forms basins in the underlying permafrost. These ponds deepen gradually during the summer and, if the temperature is high enough, they will grow in size as their rims collapse. Thermal expansion and contraction cause permafrost cracking. In the summer, water fills these cracks and forms veins called ice wedges. These wedges enlarge with seasonal freezing/thawing cycles. Some ice wedges buried for centuries are revealed during excavations or landslides. ==Climate==

According to the Köppen climate classification, Denali National Park has a subarctic climate (Dfc). The plant hardiness zone at Denali Visitor Center is 3a with an average annual extreme minimum temperature of . Long winters are followed by short growing seasons. Eighty percent of the bird population returns after the cold months, raising their young. Most mammals and other wildlife in the park spend the brief summer months preparing for winter and raising their young. Summers are usually cool and damp, but temperatures in the 70s are not rare. The weather is so unpredictable that there have even been snowstorms in August. The north and south sides of the Alaska Range have completely different climates. The Gulf of Alaska carries moisture to the south side, but the mountains block water to the north side. This brings a drier climate and huge temperature fluctuations to the north. The south has transitional maritime continental climates, with moister, cooler summers and warmer winters. ==Ecology==

The Alaska Range is a mountainous expanse that runs through the entire park, strongly influencing its ecosystems. Vegetation in the park varies with altitude. The treeline is at , causing most of the park to be a vast expanse of tundra. In the park's lowland areas, such as the western sections surrounding Wonder Lake, spruces and willows dominate the forest. Most trees and shrubs do not reach full size due to unfavorable climate and thin soils. There are three types of forest in the park, from lowest to highest: low brush bog, bottomland spruce-poplar forest, and upland spruce-hardwood forest. The forest grows in a mosaic, due to periodic fires. In the park's tundra, layers of topsoil accumulate on rotten, fragmented rock that has been moved by thousands of years of glacial activity. Mosses, ferns, grasses, and fungi grow on the topsoil. In areas of muskeg, tussocks form and may collect algae. The term 'muskeg' includes spongy waterlogged tussocks as well as deep pools of water covered by solid-looking moss. Wild blueberries and soap berries thrive in the tundra and provide the bears of Denali with the main part of their diet. Over 450 species of flowering plants fill the park and can be viewed in bloom throughout the summer. Images of goldenrod, fireweed, bluebell, and gentian filling the valleys of Denali are often used on postcards and in the artwork. and cub on the park road Denali is home to a variety of North American birds and mammals, including an estimated 300–350 grizzly bears on the north side of the Alaska Range (70 bears per 1,000 square miles) and an estimated 2,700 black bears (334 per 1,000 square miles). , park biologists were monitoring about 51 wolves in 13 packs (7.4 wolves per 1,000 square miles), while surveys estimated 2,230 caribou in 2013, and 1,477 moose in 2011. Dall sheep are often seen on mountainsides. Smaller animals such as coyotes, hoary marmots, shrews, Arctic ground squirrels, beavers, pikas, and snowshoe hares are seen in abundance. Red and Arctic fox species, martens, Canada lynx, and wolverines also inhabit the park but are more rarely seen due to their elusive natures. Many migratory bird species reside in the park during late spring and summer. There are waxwings, Arctic warblers, pine grosbeaks, and northern wheatears, as well as ptarmigan and the tundra swan. Raptors include a variety of hawks, owls, and gyrfalcons, as well as the abundant but striking golden eagles. Ten species of fish, including trout, salmon, and Arctic grayling, share the waters of the park. Because many of the rivers and lakes of Denali are fed by glaciers, glacial silt and cold temperatures slow the metabolism of the fish, preventing them from reaching normal sizes. A single amphibious species, the wood frog, also lives among the lakes of the park. There are several non-native species in the park including common dandelion, narrowleaf hawksbeard, white sweet clover, bird vetch, yellow toadflax, and scentless false mayweed. There are 28 invasive species documented in the park and 15 of these species are considered a threat. Certain areas of the park are often closed due to uncommon wildlife activity, such as denning areas of wolves and bears or recent kill sites. == Access and recreation ==

The park is serviced by the long Denali Park Road, which begins at the George Parks Highway and continues to the west parallel to the Alaska Range, ending at Kantishna. The park road is the sole vehicle access to the park. Only of the road, up to Savage River Bridge and a loop trail, is paved because permafrost and the freeze-thaw cycle would create a high cost for maintaining a paved road. Private vehicles are restricted beyond this point. Access to the interior of the park is only through tour/shuttle buses. The Pretty Rocks landslide has impacted the road at Polychrome Pass at Mile 45.4. NPS believes the landslide has been active since before the road was built, but only required moderate maintenance every 2–3 years. Beginning in 2014, the landslide accelerated considerably as permafrost thawed, requiring the road crew to spread 100 truckloads of gravel per week to keep the road passable until August 2021, when the park decided to close the road beyond Mile 45 until the summer of 2027 at the earliest. Located within the park, the Denali Bus Depot sells tickets for bus trips into the park and is the visitor contact station for campgrounds. All shuttle buses depart from here, as do some tours. The Denali Visitor Center is at mile marker 1.5 and features an exhibit hall and ranger-led programs. It is also close to the Murie Science and Learning Center, the Denali National Park railroad depot, and the McKinley National Park Airport The railroad station offers service for the Alaska Railroad's Denali Star route between mid-May and Mid-September. Three campgrounds near the park entrance are accessible by private vehicles: Riley Creek, Savage River, and Teklanika River. Camper buses provide transportation to campgrounds in the interior of the park (Sanctuary River, Igloo Creek, and Wonder Lake). All shuttle and tour buses make a stop at the Toklat River Contact Station at mile 53. Eielson Visitor Center is located four hours into the park on the road (at mile marker 66). It features daily ranger-led programs during the summer, and on clear days, views of Denali and the Alaska Range. Snow closes the Park Road past the park headquarters for the winter between October to April. However, the park remains open for cross-country skiing, snowshoeing, and dogsledding. Kantishna features backcountry lodges accessible by chartered air taxi flight to the Kantishna Airport. Lodging, restaurants, and other services are in the community of Denali Park, one mile north of the park entrance on the George Parks Highway. The rugged south portion of the park, characterized by large glacier-filled canyons, is accessed by Petersville Road, a dirt road that stops about outside the park. The mountains can be accessed most easily by air taxis that land on the glaciers. Visitors who want to climb Denali need to obtain a climbing permit first and go through an orientation at the Walter Harper Talkeetna Ranger Station in Talkeetna, Alaska, about south of the entrance to Denali National Park and Preserve. This center serves as the center of mountaineering operations. Denali has the only federal government-owned sled dog kennel, where sled dogs are raised and trained. Sled dogs were first used in the park in 1922 to patrol the area to prevent poaching and assist in park development. Park rangers continue to breed the Alaskan huskies for the traditional activity of mushing and working at the park, particularly during snowy winter. In summer, the kennel hosts dog sledding demonstrations for visitors. The kennel is part of the Mount McKinley National Park Headquarters District, which also includes administration buildings. Hiking Maintained hiking trails are at Savage River, Eielson Visitor Center, Wonder Lake, Denali Visitor Center, and the Tsenesdghaas Na' Trailhead. The park also encourages off-trail hiking. While a guide is not required to hike in Denali, many people choose to hire one for safety, navigation, and interpretation of the wilderness they're traveling through. Popular hiking trails include Rock Creek Trail, Triple Lakes Trail, Oxbow Loop, Savage Alpine Trail, Horseshoe Lake Trail, Savage River Loop, and more. Visitors can access hiking past mile 15 of the Denali Park Road by taking the East Fork Transit bus deeper into Denali National Park. The East Fork Transit is a shuttle bus that allows visitors to get on and off wherever they want. They can flag down another green transit bus to travel back to the entrance, or deeper into the National Park. ==See also==