The Andes, at a glance
The world’s longest continental mountain range, shaped by Nazca Plate subduction
~7,000 km
Length from Venezuela’s coast to Tierra del Fuego in the south.
7 countries
Venezuela, Colombia, Ecuador, Peru, Bolivia, Chile, and Argentina.
6,961 m
Aconcagua’s height, the highest peak in the Americas and outside Asia.
~200 million years
Roughly how long the Nazca Plate has been subducting beneath South America.
How Far Do the Andes Stretch, and Through Which Countries?
Which peak and which countries define the range?
- The Andes run about 7,000 kilometres, from Venezuela’s Caribbean coast in the north to Tierra del Fuego, near Cape Horn, in the south.
- They are the longest continental mountain range in the world.
- The range passes through seven countries: Venezuela, Colombia, Ecuador, Peru, Bolivia, Chile, and Argentina.
- Aconcagua, in Argentina’s Mendoza Province, is the Andes’ highest peak, at 6,961 metres. It is the highest mountain in the Americas, and the highest outside Asia.
- The range is far narrower than it is long. Its width varies from about 200 to 700 kilometres, with an average elevation of roughly 4,000 metres.
- Several national capitals sit within the Andes. La Paz, Bolivia, is the world’s highest capital city. Quito, Ecuador (2,850 m) and Bogotá, Colombia (2,625 m) sit high in the range too.
Q1. True or False: The Andes are the world’s longest continental mountain range, not its tallest or widest.
Q2. True or False: Aconcagua, the Andes’ highest peak, is located in Chile.
How Did the Andes Form, and What Landscapes Do They Create?
Why is the Atacama Desert so dry if it sits right next to the Andes?
- The Andes formed through subduction: the oceanic Nazca Plate is being forced under the continental South American Plate, a process that has been ongoing for roughly 200 million years.
- That collision crumpled and uplifted the crust, building the range. It also drives ongoing volcanic and seismic activity.
- The Andes sit on the Pacific Ring of Fire. Active volcanoes here include Cotopaxi and Chimborazo, both in Ecuador.
- The Altiplano, a high plateau within the central Andes, is shared mainly by Bolivia and Peru.
- The Atacama Desert lies on the Andes’ western flank, in Chile, and is one of the driest places on Earth. The Andes create a rain-shadow effect that blocks most moisture from reaching it.
- Bolivia, Chile, and Argentina together hold much of the world’s known lithium reserves, often called the “Lithium Triangle.” It sits within and around the Andes’ salt flats.
Q3. True or False: The Atacama Desert is one of the driest places on Earth because the Andes block most moisture from reaching it.
Q4. True or False: The Lithium Triangle comprises Chile, Bolivia, and Peru.
Think it through, before reading on. The Atacama Desert sits right on South America’s Pacific coastline, next to a vast ocean, yet it’s one of the driest places on Earth. Why doesn’t all that nearby ocean moisture reach it?
Show the explanation
Moist air moving in from the Pacific hits the Andes and is forced to rise, cooling as it climbs and dropping its moisture as rain on the mountains’ windward side. By the time that air descends the other side toward the Atacama, it has already lost nearly all its water, leaving the desert in the range’s rain shadow despite sitting so close to the ocean.
What Else Do the Andes Hold, Beyond the Mountains Themselves?
What rivers, ruins, and wildlife call the Andes home?
- Several of South America’s major rivers originate in the Andes, including headwater tributaries of the Amazon.
- The Andes are home to Machu Picchu, the Inca citadel in Peru, and the world’s highest navigable lake, Lake Titicaca, shared between Peru and Bolivia.
- The Andean condor, one of the world’s largest flying birds, ranges the full length of the Andes, from Venezuela and Colombia in the north to Tierra del Fuego in the south. It is Chile’s national bird.
- Volcanic activity in Ecuador’s stretch of the Andes is covered in depth in a separate article on the Andean Volcanic Belt.
Q5. True or False: Lake Titicaca sits entirely within Peru’s borders.
Q6. True or False: The Andean condor ranges along the full length of the Andes, from the northern countries down to Tierra del Fuego.
Remember the trap. A classic exam list names six countries (Bolivia, Brazil, Colombia, Ecuador, Paraguay, Venezuela) and asks how many the Andes pass through. The answer is four: Bolivia, Colombia, Ecuador, and Venezuela. Brazil and Paraguay are not Andean countries.
Quick Q&A
How long are the Andes, and how many countries do they cross?
About 7,000 kilometres, through seven countries: Venezuela, Colombia, Ecuador, Peru, Bolivia, Chile, and Argentina.
What is the Andes’ highest peak, and where is it?
Aconcagua, at 6,961 metres, in Argentina’s Mendoza Province, the highest peak in the Americas and outside Asia.
Why is the Atacama Desert so dry, right next to the Andes?
The Andes create a rain-shadow effect that blocks most Pacific moisture from reaching the desert’s side of the range.
Which three countries make up the Lithium Triangle?
Chile, Bolivia, and Argentina, around the Andes’ salt flats.
- UPSC CSP 2025 — A country-count question listed six countries (Bolivia, Brazil, Colombia, Ecuador, Paraguay, Venezuela) and asked how many the Andes pass through. The correct count is four, since Brazil and Paraguay sit east of the range entirely. View this question →
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