Denali National Park is a United States National Park that is home to Mt. McKinley, North America's highest mountain, known to the native Athabascan Indians as Denali. In addition, the park protects an incredible wilderness area that contains grizzly bears, caribou, moose, wolves, and numerous other creatures. It is in the state of Alaska, 240 miles north of Anchorage and 120 miles south of Fairbanks. Denali National Park comprises a massive area of six million acres, slightly more than the entire state of Massachusetts. The park is best known for the 20,320 foot Denali/Mt. McKinley (named after then-senator and future President William McKinley). The tremendous 18,000 foot difference from the mountain's lowlands near Wonder Lake up to its peak is a greater vertical relief than that of Mount Everest. The park is bisected from east to west by the Alaska Range and the Park Road is the only vehicle access into the park. The park was established in 1917 as a wildlife refuge. It was originally named Mount McKinley National Park, but in 1980 the park was renamed and expanded in size by four million acres as part of the Alaska National Interest Lands Conservation Act (ANILCA). Today the park is managed as three separate units: Denali Wilderness is made up of the original Mount McKinley National Park and is managed to retain the undeveloped wilderness with no hunting allowed. The Denali National Park management area includes some of the 1980 additions and allows subsistence hunting. Denali National Preserve includes two areas of the park within which sport and subsistence hunting are allowed on a permit basis. Denali, the "High One," is the name Athabascan native people gave the massive peak that crowns the 600-mile-long Alaska Range. Permafrost ground underlies many areas of the park, where only a thin layer of topsoil is available to support life. After the continental glaciers retreated from most of the park 10,000 to 14,000 years ago, hundreds of years were required to begin building new soils and revegetation. The dynamic glaciated landscape provides large rivers, countless lakes and ponds, and unique landforms which form the foundation of the ecosystems that thrive Denali. The terrain of Denali includes "tundra" and "taiga" zones. Taiga zones are made up of the stubby evergreen, spruce and aspen trees that are found in areas around the Arctic Circle. The taiga zone within Denali extends to approximately 2700 feet above sea level, above which few trees are found. The treeless areas of the park can generally be classified as tundra. Within a tundra zone the plants are often miniaturized, including tiny flowers, extensive mosses, and various shrubs. Be aware of the willow thickets in the tundra zone as they can be a major impediment while hiking. Congress created the park to protect its abundance of large mammals. Today it is common to see grizzly bears, caribou, Dall sheep, moose, and foxes throughout the park. Less common but still regularly seen are the park's many wolves. Black bears are also occasionally seen, and the very lucky visitor might glimpse a wolverine.