A National Parks Service ranger describes the features of a bird's feather that can be used to identify species.

Photograph by Patricia Norris, National Geographic
  • On August 25, 1916, U.S. President Woodrow Wilson signed the National Park Service Organic Act. The act officially created the National Park Service, an agency dedicated to " . . . conserv[ing] the scenery and the natural and historic objects and the wild life therein." The act also ordered the service to ensure all people can enjoy these conserved landscapes.

    Millions of people visit national parks every year. The National Park Service helps provide safe access, accurate information, and sometimes lodging around these sites. NPS must often balance the needs of sightseers, the environment, and the local community. More than 3 million visitors enjoy Yellowstone National Park every year, for example. These visitors come to see the geysers, hot springs, and wildlife for which the park is known. NPS must regulate the number of visitors in the park, however, to ensure delicate geology and habitats are not impacted by human activity. Rangers and other park personnel do this by constructing well-defined walkways and limiting the number of vehicles in the park. NPS must also control the populations of wolves and bison in Yellowstone, as these animals may have a negative impact on the livestock and agricultural land surrounding the park.

  • Term Part of Speech Definition Encyclopedic Entry
    accurate Adjective


    community Noun

    group of organisms or a social group interacting in a specific region under similar environmental conditions.

    conserve Verb

    to save or use wisely.

    delicate Adjective

    fragile or easily damaged.

    ensure Verb

    to guarantee.

    environment Noun

    conditions that surround and influence an organism or community.

    geology Noun

    study of the physical history of the Earth, its composition, its structure, and the processes that form and change it.

    geyser Noun

    natural hot spring that sometimes erupts with water or steam.

    Encyclopedic Entry: geyser
    habitat Noun

    environment where an organism lives throughout the year or for shorter periods of time.

    Encyclopedic Entry: habitat
    impact Noun

    meaning or effect.

    landscape Noun

    the geographic features of a region.

    Encyclopedic Entry: landscape
    national park Noun

    geographic area protected by the national government of a country.

    National Park Service Noun

    U.S. federal agency with the mission of caring "for special places saved by the American people so that all may experience our heritage."

    personnel Noun

    employees or all people working toward a common goal.

    regulate Verb

    to determine and administer a set of rules for an activity.

    wildlife Noun

    organisms living in a natural environment.