• A pass is a gap, or break, in high, rugged terrain such as a mountain ridge. A pass forms when a glacier or stream erodes, or wears away, the land between areas of higher terrain. Passes often provide the easiest routes for people to travel across steep mountain ranges. For this reason, they have played an important role throughout human history in migration, trade, and settlement.

    Most passes are flat at their summits and have the shape of a saddle. They can consist of very short, steep summits, or expansive valleys that stretch for kilometers. Often, passes sit just above the source of a river fed by precipitation and snowmelt.

    Passes are good places to build settlements or defensive outposts because they are usually the only flat land in a mountainous area. This vantage point also makes a pass an easier location to defend against threats or enemies.

    In some parts of the world, passes connect different cultures that are separated by the mountains between them. The Khyber Pass, which connects Pakistan and Afghanistan in the Hindu Kush mountains, has served as a key trade route between Central Asia and South Asia for thousands of years. Today, it is the route between the modern cities of Kabul, Afghanistan and Peshawar, Pakistan.

    "Pass" may also refer to a channel, or deeper part of a body of water, that allows passage through an otherwise shallow waterway.

    Hikers take a pass at Kneeknocker Pass.

    Mysterious Pass
    Hannibal (247-183 BCE) completed one of the most legendary crossings of the French Alps during the Second Punic War (218-203 BCE). Hannibal was from North Africa, the modern-day city of Carthage, Tunisia. He led not only his troops through the Alps, a formidable mountain range, but a number of war elephants as well. However, there is no record of which pass Hannibal used to cross the Alps. The subject remains intensely debated by historians.

  • Term Part of Speech Definition Encyclopedic Entry
    channel Noun

    waterway between two relatively close land masses.

    Encyclopedic Entry: channel
    consist Verb

    to be made of.

    culture Noun

    learned behavior of people, including their languages, belief systems, social structures, institutions, and material goods.

    debate Verb

    to argue or disagree in a formal setting.

    defensive Noun

    resisting attack.

    elephant Noun

    large mammal with a long trunk, native to Africa and Asia.

    erode Verb

    to wear away.

    formidable Adjective

    intimidating, or causing fear or hesitation due to difficulty.

    glacier Noun

    mass of ice that moves slowly over land.

    Encyclopedic Entry: glacier
    Hannibal Noun

    (247-183 BCE) general of the Carthaginian Empire.

    Encyclopedic Entry: Hannibal
    Khyber Pass Noun

    gap in the Hindu Kush mountains linking Pakistan and Afghanistan.

    legendary Adjective

    famous, heroic, or celebrated.

    migration Noun

    movement of a group of people or animals from one place to another.

    mountain Noun

    landmass that forms as tectonic plates interact with each other.

    pass Noun

    gap or break in rugged terrain, such as a mountain ridge.

    Encyclopedic Entry: pass
    precipitation Noun

    all forms in which water falls to Earth from the atmosphere.

    Encyclopedic Entry: precipitation
    river Noun

    large stream of flowing fresh water.

    Encyclopedic Entry: river
    rugged Adjective

    having an irregular or jagged surface.

    saddle Noun

    seat for a rider on a horse.

    Second Punic War Noun

    (218-201 BCE) armed conflict between the Carthaginian Empire and the Roman Republic.

    settlement Noun

    community or village.

    snowmelt Noun

    water supplied by snow.

    source Noun

    beginning of a stream, river, or other flow of water.

    Encyclopedic Entry: source
    stream Noun

    body of flowing water.

    Encyclopedic Entry: stream
    summit Noun

    highest point of a mountain.

    terrain Noun

    topographic features of an area.

    trade Noun

    buying, selling, or exchanging of goods and services.

    trade route Noun

    path followed by merchants or explorers to exchange goods and services.

    valley Noun

    depression in the Earth between hills.

    vantage Noun

    position or outlook.