Andes facts for kids

Quick facts for kids Andes Mountains
Spanish: Cordillera de los Andes
Map of South America showing the Andes running along the entire western part (roughly parallel to the Pacific coast) of the continent
Highest point
Peak	Aconcagua (Mendoza, Argentina)
Elevation	6,961 m (22,838 ft)
Dimensions
Length	8,900 km (5,500 mi)
Width	330 km (210 mi)
Geography
Country	Argentina Bolivia Chile Colombia Ecuador Peru Venezuela
Range coordinates	32°S 70°W / 32°S 70°W / -32; -70

The Andes Mountains are the longest continental mountain range in the world. They form a massive natural wall of highland peaks along the western side of South America. This amazing mountain range stretches across seven countries: Venezuela, Colombia, Ecuador, Peru, Bolivia, Chile, and Argentina. The entire range is about 8,900 kilometres (5,500 mi) long. In some places, it is up to 700 kilometres (430 mi) wide. The mountains have an average height of about 4,000 metres (13,000 ft).

The Andes are the highest mountain range anywhere on Earth outside of Asia. The tallest peak is Aconcagua, located in Argentina, rising 6,961 metres (22,838 ft) above sea level. Deep inside the range are wide, high plateaus where millions of people live today. The most famous is the Altiplano Plateau, the second-highest plateau on Earth after the Tibetan Plateau. The Andes are also part of the American Cordillera, which connects mountain chains across the Americas and into Antarctica.

What Does the Name Andes Mean?

The name Andes comes from an ancient indigenous language. Most historians believe it comes from the Quechua word anti, which means "east." In the ancient Inca Empire, this word gave rise to Antisuyu, the eastern region of their realm. Other experts think it might come from the older Aymara language word anta, meaning "copper." Copper is a bright orange metal that is still mined in huge quantities across the mountains.

People also call the Andes a cordillera. This comes from the Spanish word cordel, which means a small rope or string. Geographers use this word because the long lines of mountains look like parallel twisted ropes from above.

Geography: How Are the Andes Laid Out?

Aconcagua, in Argentina, the highest mountain in the Western Hemisphere and in the world outside the Himalayan system.

The Andes stretch across seven countries along the coast of the Pacific Ocean. Because the chain is so long, scientists divide it into three primary geographical zones.

The Northern Andes

The Northern Andes run through Venezuela, Colombia, and Ecuador. Here, the mountain range splits into three distinct parallel branches called cordilleras. Between these ridges sit rich river valleys and lush forests. Near the northern coastline stands the Sierra Nevada de Santa Marta, a tall isolated range near the sea. Farther out in the Caribbean Sea, islands like Aruba, Bonaire, and Curaçao were once thought to be submerged mountain tips. Geologists now know they sit on complex borders between the South American Plate and the Caribbean Plate.

The Central Andes

The Central Andes run through Peru and Bolivia. This is the widest section of the entire mountain range. In this region, the mountains spread apart around a giant elevated plain called the Altiplano. Great peaks rise here, such as Huascarán at 6,768 metres (22,205 ft) in Peru and Illimani at 6,438 metres (21,122 ft) in Bolivia. Major cities, ancient ruins, and high lakes nestle between these giant rocky crests.

The Southern Andes

The Southern Andes stretch southward through Chile and Argentina. As the mountains travel toward the southern tip of the continent, they pass the giant volcano Llullaillaco. Eventually, they reach the windswept islands of Tierra del Fuego. In this chilly southern region, the mountains are carved by icy fjords, tumbling mountain rivers, and massive frozen fields of blue ice.

Geology: How Did These Giant Mountains Form?

Aerial view of Valle Carbajal in the Tierra del Fuego. The Andes range is about 200 km (124 mi) wide throughout its length, except in the Bolivian flexure where it is about 640 kilometres (398 mi) wide.

The Andes formed through a long mountain-building process known as an orogeny. The range sits directly along the Pacific Ring of Fire, a famous horseshoe-shaped belt known for frequent volcanic activity and shaking earth.

The story of the Andes began hundreds of millions of years ago when the ancient supercontinent Pangaea split apart. Great cracks and rift valleys opened across the land. During the ancient Triassic, Jurassic, and Cretaceous periods, pieces of the Earth's crust called tectonic plates began smashing into one another.

Plate Tectonics and Mountain Uplift

Mururata and Illimani in Bolivia, two prominent peaks formed by the tectonic uplift caused by the Andean orogeny and plate subduction.

The biggest engine powering the Andes is subduction. Subduction happens when a heavy slab of oceanic crust, the Nazca Plate, slides under the lighter South American Plate. In the far south, part of the Antarctic Plate also slides beneath the continent. As these colossal slabs of rock push together, the edge of the continent gets crumpled, squeezed, and pushed upward.

This crustal shortening forces layers of sedimentary rock and metamorphic rock to buckle. They create immense folds, producing dramatic uplifting across thousands of miles. Across the stormy waters of the Drake Passage, the frozen peaks of the Antarctic Peninsula south of the Scotia Plate represent the southern continuation of this chain.

To the east, the Andes are bordered by giant lowlands and sedimentary basin systems. These include the Orinoco Basin, the vast Amazon Basin, the Madre de Dios Basin, and the warm Gran Chaco. These basins separate the high peaks from the ancient stable continental rocks known as cratons, including the ancient Amazonian craton. In the far south, the mountains connect with the ancient rocks of the Patagonia Terrane.

Bends in the Mountain Chain

The Andes do not form a straight line. Instead, they have giant bends called oroclines. The most famous bend is the Bolivian Orocline at latitude 18°S, often called the Arica Elbow. Here, the coast of South America and the mountain range make a sharp turn. The northern mountains run northwest toward Peru, while the southern mountains run directly south through Chile and Argentina. The bending rocks squeezed together, helping build the massive width of the Altiplano. Further south sits the Maipo Orocline, followed by the Patagonian Orocline near the southern tip of the continent.

Earthquakes and Tremors Along the Andes

Because the Nazca Plate is constantly grinding beneath the South American Plate, the Andes experience powerful earthquake events. Friction builds up deep underground until the rocks suddenly slip, sending shockwaves through the ground.

Some of the most powerful earthquakes ever recorded have occurred along this active subduction zone. The famous 1960 Valdivia earthquake in Chile measured magnitude 9.5, making it the strongest earthquake ever detected by scientific instruments. Other major events include the 2010 Maule earthquake (magnitude 8.8) and the 2015 Illapel earthquake (magnitude 8.2).

Earthquakes do not just happen offshore. Shallow intraplate earthquakes also strike within the South American Plate itself. The 1947 Satipo earthquake in Peru reached magnitude 7.5, causing severe shaking in mountain valleys. Geologists study fault lines, such as the 1946 Ancash earthquake break and the 1969 Huaytapallana earthquake rupture, to understand how the crust responds to compression. In the far south, a major transform fault slides horizontally between Tierra del Fuego and the small Scotia Plate.

Volcanoes: Fiery Peaks of the Andes

Sol de Mañana, an area of intense geothermal activity with fumaroles and geysers, Bolivia

This photo from the ISS shows the high plains of the Andes Mountains in the foreground, with a line of young volcanoes facing the much lower Atacama Desert

The Andes are home to many of the highest volcanoes on the planet. Deep underground, subducting plates melt under intense heat and pressure, creating glowing pockets of liquid rock called magma. This magma rises through cracks to feed erupting volcanoes at the surface.

Geologists group these peaks into the Andean Volcanic Belt. The belt features four main active zones separated by areas of inactivity. It contains an incredible variety of volcanic landscapes, including bubbling hot springs, whistling steam vents called fumaroles, and spurting geyser fields like Sol de Mañana in Bolivia.

Some of the world's most impressive volcanoes tower over the Andes:

• Ojos del Salado: Rising to 6,893 metres (22,615 ft) on the border between Chile and Argentina, this is the highest active volcano on Earth.
• Chimborazo: Located in Ecuador, its summit is special. Because the spinning Earth bulges around the equator, Chimborazo's peak is the farthest point on Earth from the center of our planet.
• Cotopaxi: A famous snow-capped stratovolcano in Ecuador that rises 5,897 metres (19,347 ft) into the sky.

Valuable Treasures Underground: Minerals and Salt Flats

"Cono de Arita" in the Puna de Atacama, Salta (Argentina)

The Andes are packed with incredible mineral riches. Long ago, superheated underground water called hydrothermal fluid flowed through cooling volcanic rocks called plutons. These fluids deposited thick veins of valuable metals throughout the crust.

Copper and Precious Metals

The western slopes of the Andes hold massive porphyry copper deposits. Thanks to these reserves, Chile and Peru are the number one and number two producers of copper in the world. Enormous open-pit operations like Chuquicamata and Escondida in Chile, along with Toquepala in Peru, provide metal used in electrical wiring and electronics. Peru also hosts one of the largest gold mines in the world, the Yanacocha mine.

In Bolivia, the famous mountain Cerro Rico at Potosí once produced vast fortunes of silver during the Spanish colonial era. Bolivia's mountains also contain the famous Bolivian tin belt, rich in useful industrial metals.

Giant Salt Flats and Modern Battery Power

In the dry high plateaus of the central Andes, ancient lakes dried up thousands of years ago, leaving behind blindingly white salt plains called salars. The Salar de Atacama in Chile and the Salar de Uyuni in Bolivia are the most famous.

These salt flats hold the world's largest supplies of lithium. Lithium is a lightweight metal essential for rechargeable batteries used in electric cars, laptops, and smartphones. Argentina, Bolivia, and Chile hold so much lithium that the region is often called the "Lithium Triangle." In earlier centuries, dry desert basins were mined for saltpeter deposits, an important mineral used in fertilizers.

Weather and Climate Across the Peaks

Central Andes

Bolivian Andes

Because the Andes are so long and tall, they experience almost every kind of weather on Earth. The climate changes dramatically depending on latitude, height above sea level, and distance from the sea.

Geographers divide the Andes into three main climate zones:

• The Tropical Andes: Running through Venezuela, Colombia, Ecuador, and northern Peru, this region is warm and humid. Steaming rainforests grow on the lower slopes, while chilly winds sweep the high peaks.
• The Dry Andes: Stretching across southern Peru, Bolivia, and northern Chile, this area receives very little rain. It borders the hyper-arid Atacama Desert, one of the driest places on Earth.
• The Wet Andes: Located in southern Chile and southwestern Argentina, this region gets frequent rain, snow, and strong Pacific winds.

High Mountains and Glaciers

As you climb higher up any mountain, the air gets thinner and colder. The point where snow remains frozen year-round is called the snow line. In the warm northern tropics, the snow line sits very high, between 4,500 and 4,800 metres (14,800 and 15,700 ft). In the freezing south of Tierra del Fuego, the snow line drops to just 300 metres (980 ft), allowing massive ice sheets to touch the ocean.

In high, dry areas like central Chile and Argentina's Mendoza Province, sunny skies melt ordinary surface glaciers. Instead, curious formations called rock glaciers develop. These are slow-moving rivers of frozen rock, rubble, and ice buried beneath protective gravel blankets.

Amazing Plant Life in the Andes

Laguna de Sonso tropical dry forest in Northern Andes

The Andes are a major biodiversity hotspot, home to around 30,000 different species of vascular plants. Roughly half of these plants are endemic, meaning they grow naturally nowhere else in the world!

Cloud Forests and Medicine Trees

On the eastern slopes of the Northern and Central Andes, warm Amazonian air rises and cools, creating misty cloud forest ecosystems known as the Yungas. These forests stay constantly wet and green.

One of the most famous Andean trees is Cinchona pubescens. Its bark contains quinine, a medicine used for centuries to treat malaria. Andean peoples also domesticated everyday food crops, including the nutritious potato, hearty quinoa, and tobacco.

The Rugged Polylepis Trees

High up in the cold, windy mountains where most trees cannot survive, special dwarf forests manage to thrive. These are the Polylepis trees, known locally as queñua or yagual. They can grow at elevations above 4,500 metres (14,800 ft).

Polylepis trees protect themselves from freezing temperatures with thick, papery bark that peels off in thin layers. Sadly, centuries of cutting wood for heating have caused serious forest loss. Today, these rare high-altitude forests are endangered, and local conservationists work hard to protect the remaining groves.

Incredible Wildlife: Animals of the Peaks and Valleys

A male Andean cock-of-the-rock, a species found in humid Andean forests and the national bird of Peru

A guanaco in Torres del Paine National Park, Chile.

The Andes provide homes for an astonishing variety of creatures. Scientists have documented nearly 1,000 kinds of amphibians, 600 species of mammals, 1,700 species of birds, and over 600 species of reptiles across the range.

The Camel Family of South America

Four members of the camel family roam the Andes. Two are wild animals, and two are domesticated animals raised by farmers:

• Vicuña: A graceful wild camel with extremely fine, soft golden wool that lives in the high Altiplano.
• Guanaco: A larger, hardy wild camel that roams open grasslands from Peru down to windy Patagonia.
• Llama: A large domesticated animal used for thousands of years as a sturdy pack animal to carry heavy loads up mountain trails.
• Alpaca: A smaller domesticated animal bred especially for its warm, fluffy wool, which is knitted into sweaters, hats, and blankets.

Flying Masters and Rare Animals

The Yungas region between Bolivia and Peru, part of the tropical andes

Soaring high on thermal updrafts is the mighty Andean condor. With a wingspan reaching over 3 meters (10 feet), it is the largest flying bird in the Western Hemisphere. Other unique birds include the bright orange Andean cock-of-the-rock (the national bird of Peru), colorful mountain toucans, glittering quetzals, and tiny hummingbirds like high-altitude hillstars. In shallow salty lakes, flocks of bright pink flamingos filter food from the brine.

On the ground, small furry chinchillas scurry among rocky cracks. Wild predators like the stealthy cougar and mountain foxes hunt across grassy steppes. Hidden deep in lush mountain forests are shy animals like the spectacled bear (South America's only native bear species), the gentle mountain tapir, and the rare yellow-tailed woolly monkey. High in the mountains, Lake Titicaca provides a home for unusual endemic animals, including the giant Titicaca water frog and the Titicaca flightless grebe.

Human History: Ancient Civilizations and the Inca

Frederic Edwin Church, Heart of the Andes, 1859.

People have lived in the Andes for thousands of years. Early inhabitants were hunter-gatherers who followed herds of wild game. Over centuries, these communities invented advanced irrigation systems and learned to grow crops on steep slopes.

The Rise of the Inca Empire

During the 15th century, the Inca civilization built a vast realm across the Central Andes. The Inca were brilliant engineers and planners. They built thousands of miles of paved stone roads that crossed deep gorges using swinging suspension bridges. To supply dry towns with fresh water, they carved long stone aqueducts.

The Inca farmed steep mountain slopes by constructing terracing—giant stone steps carved into hillsides that created flat soil beds for growing crops. Their mountain capital was Cusco, high in the Peruvian Andes. High on a mountain ridge near the Amazon basin sits Machu Picchu, an incredible stone citadel that was never found by invading armies.

Arrival of the Spanish and Independence

In 1532, Spanish conquistadors led by Francisco Pizarro entered the Andes. Weakened by civil conflict and new diseases, the Inca Empire was defeated. The Spanish established mines across the mountains to extract valuable silver and gold.

Three centuries later, in the early 19th century, people across South America rose up against foreign colonial control during the Spanish American wars of independence. Revolutionary leaders like Simón Bolívar and José de San Martín led brave armies across freezing Andean mountain passes to win freedom. These battles established the modern independent nations that share the Andes today.

Major Cities in the High Andes

Millions of people live in modern cities built high inside Andean valleys and plateaus:

• Bogotá: The capital of Colombia, situated on a high plateau with over 10 million residents in its metropolitan area.
• Santiago: The capital of Chile, resting in a long central valley framed by snowy peaks.
• Quito: The capital of Ecuador, sitting high on the volcanic slopes near the equator.
• La Paz: The seat of government for Bolivia and the highest capital city in the world, located at 3,650 metres (11,980 ft). Right next to it is El Alto, which rises up to 4,200 metres (13,800 ft).
• Cusco: The historic mountain capital of the Inca Empire in Peru.

• Major cities in the Andes
• 

  La Paz, Bolivia, the world's highest capital city.

• 

  Quito, Ecuador

• 

  Bogotá, Colombia

• 

  Santiago, Chile

• 

  Cusco, Peru

Transportation Across Rugged Heights

The Paso de Jama between Jujuy (Argentina) and Antofagasta (Chile).

Building roads and railways through the Andes has always been a tremendous challenge for civil engineering. Towering walls of rock, steep cliffs, loose scree, and freezing blizzards make road work difficult and expensive.

Mountain Passes and Tunnels

Vehicles cross the high mountains through special low gaps called mountain passes. One of the most famous crossings between Argentina and Chile is the Paso Internacional Los Libertadores, which winds through hairpin turns high in the mountains. Another famous high crossing is the Paso de Jama, connecting northern Argentina with northern Chile.

Trains, Planes, and Pack Animals

In several regions, engineers built remarkable high-altitude railroad lines that cling to sheer cliffs, pass through mountain tunnels, and cross dizzying bridges. Because traveling across mountain roads takes a long time, many travelers fly between major Andean cities by airplane.

In remote villages where cars cannot travel, local people still rely on sturdy pack animals. The llama, donkey, mule, and horse remain helpful friends for carrying farm produce and supplies along narrow mountain paths.

Life and Work: Farming and Mining

Chakana Winery Plantation in Luján de Cuyo, Argentina.

Peruvian farmers sowing maize and beans.

People living in the Andes have developed clever ways to earn a living in high, dry, or chilly environments.

Mountain Agriculture

Andean farmers grow different crops at different elevations:

• Low and warm valleys: Farmers grow crops like coffee, cotton, and sugarcane.
• Mid-elevation slopes: Farmers plant fields of maize (corn), beans, and vegetables.
• High chilly plains: Farmers plant cold-hardy crops like quinoa, barley, and hundreds of colorful varieties of potato.

In high, dry plateaus, farmers use irrigation canals to bring water from melting snow to their fields. Where crops cannot grow, wide open grassy plains called pastures provide grazing space for herds of sheep, llamas, and alpacas.

A quinoa field in the Bolivian altiplano

Modern Mining Industry

Chilean huasos, 19th century

Mining is one of the most important economic industries in the Andean region. Huge modern operations produce copper, silver, gold, tin, and iron.

Working in high-altitude mines is physically demanding. At elevations over 4,000 meters (13,000 feet), the air has far less oxygen, and temperatures drop well below freezing. Engineers must also protect local environments, ensuring that mining operations do not harm fragile glacial streams that supply drinking water to cities downstream.

Famous Mountain Peaks of the Andes

An aerial view of the Andes between Santiago in Chile and Mendoza, Argentina with a large ice field on the southern slope of San José volcano (left), Marmolejo (right), and Tupungato (far right).

The Andes feature dozens of famous towering summits that attract hikers and mountaineers from all over the world.

Argentina

Border Between Argentina and Chile

Bolivia

Border Between Bolivia and Chile

Chile

Colombia

Ecuador

Peru

Venezuela

See also

In Spanish: Cordillera de los Andes para niños

• List of mountains in the Andes
• Andesite line
• Apu (god)
• List of mountain ranges
• Sutter Buttes