A national park, according to international criteria, is a relatively large area--at least 1,000 ha (2,471 acres) or more--whose natural features and ecology, including plants and animals, are of great beauty, scientific interest, and recreational and educational value. National parks are protected by laws and law-enforcement officers and are entered by visitors only under special conditions that preserve the features for which the parks were established. Because much of the world's unique heritage is endangered by pollution, the advance of human settlements, conflicts over the use of land and resources, and other problems, many countries are setting aside national parks as rapidly as possible. In the 1880s fewer than ten national parks existed, in Australia, Canada, and the United States. By the late 1980s far more than 2,000 national parks and equivalent reserves had been established by more than 100 countries, with the number of new parks increasing each year. U. S. NATIONAL PARK SYSTEM The national-park movement began in the United States in 1870 when a group of explorers recommended that a portion of the upper Yellowstone River region be set aside to protect its geothermal features, wildlife, forests, and unique scenery for future generations. The idea of preserving land for public use was not new, for there had long been public parks, but \TYellowstone\t, established in 1872, set the pattern for preserving large undisturbed ecosystems as national parks. The idea caught on, and Congress established many new parks. Some were a gift from a state to the federal government, as in the case of \TYosemite\t. Some were first established by presidential proclamation as national monuments. Some lands were given by individuals, notably John D. Rockefeller. Often commercial interests, especially the western railroads, actively promoted the creation of national parks. Overseeing such a growing, complex domain proved so difficult at first that, from 1886 to 1916, the U.S. Army administered and protected the parks. In 1916, Congress created the National Park Service, part of the Department of the Interior, to oversee the park system. The national park system gradually grew in diversity by the addition of historic and prehistoric sites, together with battlefields, parkways, hiking trails, seashores, lakeshores, rivers, recreation areas, memorials, scientific reserves, and other areas. By the 1980s more than 300 of these diverse units, including the national parks themselves, made up the national park system and encompassed more than 32 million ha (79 million acres). More than half of these units are dedicated to historic preservation, but 95% of the area of the park system protects natural features. Millions of people visit the United States national park system each year--364.6 million people in 1986. A number of parks, such as the \TEverglades\t in Florida, basically protect biological features. A famous park preserving a geological phenomenon is \TGrand Canyon\t, in Arizona. Some national monuments, such as \TDeath Valley\t in California and Glacier Bay in Alaska, have a larger land area than most national parks. Although the difference between national park and national monument status is frequently hazy, in general a national park is more outstanding in relation to the national heritage and usually more complex scientifically and historically. A host of parks are important in American history. Some of the better-known parts of the system include the \TStatue of Liberty\t, in New York City; the \TWhite House\t, in Washington, D.C.; \TIndependence Hall\t and the \TLiberty Bell\t, in Philadelphia; Appomattox Court House, in Virginia, where Lee's surrender to Grant ended the Civil War; and the site where the first transcontinental railroad lines met, Golden Spike National Historic Site, in Utah. Each park is under the direction of a superintendent who is directly responsible for all aspects of operating the park. He or she is usually assisted by a staff of administrative personnel, rangers, naturalists, historians, maintenance personnel, and others. The park interpreters give talks, conduct nature walks, lead campfire programs, tend museums, do research, and maintain a park's extensive library and specimen collections. In Washington, D.C., the National Park Service is headed by a director, who in turn reports to the secretary of the interior. The funds required to manage the park system and establish new areas are appropriated annually by Congress. Park facilities, such as hotels, restaurants, gasoline stations, stores, shops, and public transportation systems, are operated as private concessions granted by the federal government. These concessionaires must adhere to specific regulations--which are often the subject of considerable conflict. Enlargement of a national park is accomplished principally through congressional legislation. In the mid-1960s, Congress directed the National Park Service to establish wilderness areas within existing parks, which are designed to preserve environments largely untouched by human impact. In the mid-1970s, on the other hand, Congress mandated the service to provide parks in large urban areas. CANADIAN NATIONAL PARK SYSTEM The national park system of Canada began with the establishment of Banff National Park, Alberta, in 1885. Since then the total area of Canada's parks has expanded to about 180,000 sq km (69,498 sq mi). The system includes 32 national parks and 80 national historic parks and sites. The national historic parks preserve such features as forts, houses, canals, and trails. In general, management policies differ little from those in the United States. Bilingual programs (French and English) are evident nearly everywhere. Visitors to Canadian parks--about 25 million annually--enjoy interpretive programs of the same high standard as in the United States. As in the United States, most of the national parks are in the west. Among the best-known parks are Jasper and Waterton Lakes (the latter adjacent to Glacier National Park, in Montana), both in Alberta; Kootenay and Yoho, in British Columbia; Kluane, in Yukon Territory; and Fundy, in New Brunswick. Newer wilderness-type parks have been established in the Arctic, such as Auyuittuq (1972) on Baffin Island. NATIONAL PARKS ELSEWHERE Based largely on the United States model, an immense collection of national parks has come into being around the world. Australia established its first park in 1879; New Zealand, in 1894. What was to become South Africa's famed 19,485-sq km (7,523-sq mi) \TKruger\t \Tnational park\t first came under protection in 1898 (national park status: 1926). Sweden (1909), Russia (1911), France (1913), Switzerland (1914), and many other countries soon established parks. Great strides were made in the 1930s in Argentina, Chile, and Ecuador. Japanese officials, after visiting the United States, began (1934) to build a system that now occupies slightly more than 5% of the country's total land area. After World War II a number of outstanding African parks were set aside; some of the largest included Serengeti (Tanzania), Ruwenzori (Uganda), Tsavo (Kenya), Wankie (Zimbabwe), and Kafue (Zambia). The world's highest and most scenic waterfalls, and many of the highest and most scenic mountains, on nearly every continent are in national parks. Many parks constitute immense wild-animal reserves, as on the African plains. Some wildlife concentrations have great historic significance, such as those island species studied (1835) by Charles Darwin in what is now Galapagos National Park, Ecuador. Certain parks and reserves are important as the last refuges of animal species once nearly extinct, such as Bialoweiza National Park (Poland), which protects the European bison. The tendency of many governments has been to establish as many parks as possible before advancing civilization alters the character of natural environments. Likewise, the sizes of individual parks have reached extremes. Greenland National Park (1974), for example, covers one-third of Greenland, an area larger than Texas. Whereas the most important goal of national parks is preserving the national heritage, the developing countries place special emphasis on economic benefits, especially through tourism. Mostly because of national parks, tourism in Kenya is the country's largest source of foreign exchange. It is a difficult task, however, to find local experts who can plan and manage parks in developing countries. Frequently, these countries do not possess the economic means to establish and maintain areas at national-park standards. Students and officials of numerous nations have undertaken training in the United States and elsewhere. PROBLEMS AND PROSPECTS Some of the problems associated with national parks result when the delicate balance of the natural environment is disrupted. One problem is the presence of exotic or introduced species that encroach on the habitats of native animals. Goats are a widespread culprit, as destruction in the Galapagos Islands and elsewhere attests. Many other such out-of-place animals are causing widespread damage that calls for stringent measures. Even native animals given protection may multiply so rapidly that their large numbers threaten to destroy the park environment. Other animal species may suffer, and plant and water resources are endangered. Two examples of this are the African elephant and the Yellowstone elk. The most challenging problems facing national parks result from human impact. Sometimes these problems originate outside the park. Acid rain, plus pollutants in rivers, the sea, and the air, bring into pristine park environments chemicals against which native life forms have evolved no protection. Consequently, life in lakes, rivers, and bays has been threatened, damaged, or destroyed. With the tremendous growth of popular interest in national parks beginning during the 1960s, overuse became a serious problem in many countries, including the United States and Japan. In the United States the National Park Service created a special police force to handle the large numbers of visitors. Increased use places a strain on the parks' environment and makes misuse harder to control. Such problems as poaching of protected species have proved exceedingly difficult to control, especially in the big-game parks of East Africa. Special problems result when national parks occupy the home of traditional indigenous peoples. When early national parks were created, such as those in the western United States, the Indians' lands were alienated. In many countries, however, traditional groups still occupy the land, as at Kalahari Gemsbok National Park (South Africa), where the San (Bushmen) live. When indigenous peoples live within the parks, their economic and social systems are often threatened both by restrictive measures designed to protect the environment and by their contact with visitors. Some governments, therefore, allow the groups to retain varying degrees of control over the parks. In Australia, Kakadu National Park is the home of Aborigines whose tribal council gave the land in trust to the federal government for 99 years. The tribe members are allowed to hunt and decide where visitors are permitted to go. As more wild areas are established, and even more are sought, a cry arises from miners, farmers, and developers: how much wilderness is enough? These conflicts are increasing as the world's resources become scarcer. Many national parks were created to preserve areas of outstanding scenic beauty, such as mountains. At the time of establishment it was often believed that the land was not economically usable. Many parks, however, do possess exploitable resources, and their control is a source of conflict between conservationists and developers. Portions of Australia's Great Barrier Reef were threatened (1960s) by mining interests seeking to conduct exploratory offshore drilling, but the park itself was expanded. Conflicts over water are common and frequently result from proposed dams threatening parklands. Despite a bitter struggle during the mid-1960s, U.S. conservationists were unable to prevent the Colorado River in Glen Canyon from being dammed to create Lake Powell. In recent years many parks throughout the world have lost timber to the logging industry, including Nahuel Huapi, the largest national park in Argentina. Because public lands, often uninhabited, have been largely acquired for park purposes already, it is no longer as easy to establish parks. Some countries, mostly developing nations, are now attempting to eliminate the adversary relationship between conservationists and developers before parks are established by integrating both preservation and long-term resource needs in the planning stages. The actual location of the national park becomes a key factor. In Brazil some national parks are surrounded by protected areas where multiple land use is permitted, thus "cushioning" the fragile inner environment while allowing controlled resource exploitation in the surrounding area. Thus some long-range trends have become clear. Scores of governments have demonstrated a fundamental desire to conserve natural and historic places. Visitors are better informed about the world around them. And there is a more acute awareness of the extraordinary economic benefits of national parks. Given all this, it seems safe to conclude that governments throughout the world are adopting various versions of the 1916 congressional act that mandated the work of the U.S. National Park Service. This service, said the act, shall conserve the parks in such manner and by such means as will leave them unimpaired for the enjoyment of future generations. Ann and Myron Sutton Bibliography: Butcher, Devereux, Exploring Our National Parks and Monuments, 8th rev. ed. (1985); Conservation Foundation, National Parks for a New Generation (1985); Curry-Lindahl, Kai, and Harroy, Jean-Paul, National Parks of the World (1972); Frome, Michael, National Park Guide (published annually); Harris, D. V., and Kiver, E. P., The Geologic Story of the National Parks and Monuments, 4th ed. (1985); Hartzog, George B., Battling for the National Parks (1988); McNeeley, J. A., and Miller, K. R., eds., National Parks, Conservation, and Development (1984); National Parks and Conservation Association, Our Common Lands, ed. by D. J. Simon (1988); Smallwood, Carol, An Educational Guide to the National Park System (1989); Sutton, Ann and Myron, Wilderness Areas of North America (1974); Tilden, Freeman, The National Parks, 3d ed. (1986); United Nations World Heritage List (1986).