Mountain climates change the higher up you go. Lower down they support a lot of vegetation and trees. Higher up there are only ground plants. Some mountains reach higher than the clouds. At this altitude the extreme cold and high winds cause blizzards.

In some mountainous areas the rivers are permanently frozen. These are called glaciers. Some mountains you can't see because they are under the sea.

People as well as plants have adapted to mountain life. The South American Uru tribe have larger hearts and lungs to breathe the thin air at high altitudes. Mountaineers use tanks of oxygen to help them breathe.

Mountains have many other uses. Climbers and tourists visit them for the scenery. Farmers graze their animals on them. Water authorities make reservoirs and pump the water to towns and cities. Forestry companies grow coniferous forests and harvest wood on them.