Mountain range

A mountain range, also called mountain chain or mountain belt, is a geographic area with many mountains. A mountain system, or system of mountain ranges, includes geological features that are in the same region as a mountain range.

Mountain ranges usually include highlands or mountain passes and valleys. Individual mountains in the same range do not always have the same geology or petrology. They may be a mix of different orogenic expressions and terrains, such as thrust sheets, uplifted blocks, fold mountains, and volcanic landforms. That results in a variety of rock types.

 Major ranges 
Most geologically young mountain ranges on the Earth's land surface are associated with either in the Pacific Ring of Fire or the Alpide Belt. The Pacific Ring of Fire includes the Andes of South America and extends through the North American Cordillera, along the Pacific Coast, the Aleutian Range, to the Kamchatka Peninsula, Japan, Taiwan, the Philippines, Papua New Guinea, and then New Zealand. The Andes is  long and is often described as the world's longest mountain system.

The Alpide belt includes Indonesia and Southeast Asia, through the Himalayas, and ends in the Alps. The belt also includes other European and Asian mountain ranges. The Himalayas contain the highest mountains in the world, including Mount Everest, at  of elevation.

Mountain ranges outside both systems include the Arctic Cordillera, the world's northernmost mountain system. If the definition of a mountain range includes underwater mountains, the ocean ridges form the longest continuous mountain system on Earth, with a length of .

 Divisions and categories 
Many mountain ranges have sub-ranges within them that can be thought of as a parent-child relationship. For example, the Appalachian Mountains range is the parent of its own ranges, two of which are the White Mountains and the Blue Ridge Mountains. The White Mountains are a child of the Appalachians, and there are also children of the Whites like the Sandwich Range and the Presidential Range. 

 Climate 
The position of mountains influences climate such as rain or snow. When air masses move up and over mountains, the air cools, which causes precipitation (rain or snow). As the air descends on the leeward (downwind) side, it warms again and is drier since it has been stripped of much of its moisture. Often, a rain shadow occurs on the leeward side of a range.

 Erosion 
Mountain ranges always have erosion at work while the mountains are being uplifted and long afterward until the mountains are reduced to low hills and plains. The basins next to an eroding mountain range are filled with sediments, which are buried and turned into sedimentary rock.

The early Cenozoic uplift of the Rocky Mountains of Colorado are an example. As the uplift occurred, some  of mostlyMesozoic sedimentary strata were removed by erosion and spread as sand and clays across the Great Plains to the east. This mass of rock was removed as the range actively underwent uplift.

 References 

 Other websites 

 Peakbagger Ranges Home Page
 Bivouac.com