Тау жолы мен өткелдері

Route through a mountain range or over a ridge

A mountain pass is a navigable route through a mountain range or over a ridge. Since mountain ranges can present formidable barriers to travel, passes have played a key role in trade, war, and both human and animal migration throughout history. At lower elevations it may be called a hill pass. A mountain pass is typically formed between two volcanic peaks or created by erosion from water or wind.

Mountain passes make use of a gap, saddle, col or notch. A topographic saddle is analogous to the mathematical concept of a saddle surface, with a saddle point marking the minimum high point between two valleys and the lowest point along a ridge. On a topographic map, passes can be identified by contour lines with an hourglass shape, which indicates a low spot between two higher points. In the high mountains, a difference of between the summit and the mountain is defined as a mountain pass. Passes are often found just above the source of a river, constituting a drainage divide. A pass may be very short, consisting of steep slopes to the top of the pass, or a valley many kilometers long, whose highest point might only be identifiable by surveying. Roads and railways have long been built through passes. Some high and rugged passes may have tunnels bored underneath a nearby mountainside, as with the Eisenhower Tunnel bypassing Loveland Pass in the Rockies, to allow faster traffic flow throughout the year. The top of a pass is frequently the only flat ground in the area, and may be a high vantage point. In some cases this makes it a preferred site for buildings. If a national border follows the ridge of a mountain range, a pass over the mountains is typically on the border, and there may be a border control or customs station, and possibly a military post. For instance, Argentina and Chile share the world's third longest international border, long, which runs north–south along the Andes mountains and includes 42 mountain passes. The term col, derived from Old French, is also used, particularly in Europe. In the highest mountain range in the world, the Himalayas, passes are denoted by the suffix "La" in Tibetan, Ladhakhi, and several other regional languages. Examples are the Taglang La at 5,328 m (17,480 ft) on the Leh Manali highway, and the Sia La at 5,589 m (18,337 ft) in the Eastern Karakoram range. Scotland has the Gaelic term bealach (anglicised "balloch"), while Wales has the similar bwlch (both being insular Celtic languages). In the Lake District of north west England, the term hause is often used, although the term pass is also common—one distinction is that a pass can refer to a route, as well as the highest part thereof, while a hause is simply that highest part, often flattened somewhat into a high level plateau. In Japan they are known as tōge, which means "pass" in Japanese. The word can also refer to narrow, winding roads that can be found in and around mountains and geographically similar areas, or specifically to a style of street racing which may take place on these roads.

There are thousands of named passes around the world, some of which are well known, such as the Khyber Pass close to the present day Afghanistan Pakistan border on the ancient Silk Road, the Great St. Bernard Pass at in the Alps, the Chang La at , and the Khardung La at in Ladakh, India. The roads at Mana Pass at and Marsimik La at , on and near the China–India border respectively, appear to be world's two highest motorable passes. Khunjerab Pass between Pakistan and China at is also a high altitude motorable mountain pass. One of the famous but non motorable mountain passes is Thorong La at in Annapurna Conservation Area, Nepal.