Some mountains form when the big slabs of rock—called tectonic plates—that make up the Earth’s crust crash into each other. Over millions of years, the sheets of rock push up and over one another, creating the mountain. Others form when vents in the Earth’s surface erupt and spew lava out onto the ground. The lava piles up and cools. Over millions of years, the many layers of hard lava become a mountain.
Mountains are on every continent. The longest mountain range is over 40,000 miles long—and 90 percent is under the ocean! Called the Mid-Ocean Ridge, it wraps around the globe like the seams of a baseball. The longest aboveground mountain range is the Andes. Running along the entire west coast of South America through seven different countries—including Argentina, Chile, and Colombia—it’s 4,700 miles long.
Mount Everest, on the border of Nepal and China in Asia, is the highest mountain above sea level in the world. Towering at just over 29,000 feet it would take almost 5,000 grown men stacked on top of each other to reach that high.
From bottom to top, a mountain has several biomes of life. At the very bottom, foothills often have lush deciduous forests, meaning that the trees lose their leaves in winter. Higher up are coniferous forests with tall pines and other evergreen trees.
The farther up a mountain one climbs, the colder it gets—about one degree Fahrenheit cooler every 300 feet. This is usually where the 'tree line' ends, and the where plants become much smaller. Mosses and lichens grow low to the ground, and in the spring, alpine meadows in places such as the Rocky Mountains in western North America and the Alps in Europe come alive with wildflowers. The air also becomes thinner towards the top because oxygen molecules are more spread out, making it harder to breathe.
Most plants can’t thrive at the top of some superhigh mountains—such as Mount Everest and Mont Blanc in the Alps in Europe. There, all you have is just snow-covered rocks!
Mountains often have extreme climates, and the animals that live there have some amazing adaptations. For instance, the red panda in Asia’s Himalaya grows a thick coat. Some animals' fur is more than insulation. Living in the mountains of North America, snowshoe hares have snow-white coats that help them hide from mountain lions and other predators.
Grizzly bears and hoary marmots living in the mountains of North America survive the cold winters by hibernating—hiding out in dens and resting—to conserve energy when food is hard to find. When grizzly bears hibernate, their body temperature drops by about 12 degrees, and they take a breath only once about every 45 seconds. Other animals, like mountain goats and ibexes living in Europe's Alps, migrate to lower, warmer elevations during the winter. These animals have tough but flexible hooves to steady themselves when climbing up and down the rocky terrain looking for food.
Just like these animals, you can also have fun on a mountain—you’ll just need to figure out how to hike without hooves!