The Highest Peaks in the Andes: Climbing South America’s Roof

Aconcagua is the highest peak in the Andes, the highest peak outside Asia, and the tallest mountain on the American continents. It is also one of the Seven Summits, making it the most commercially climbed mountain in South America. The first ascent on January 14, 1897 by Swiss guide Matthias Zurbriggen during Edward FitzGerald’s expedition remains one of the major milestones in early high-altitude mountaineering.

The standard Normal Route via Plaza de Mulas base camp involves no technical climbing — a fit, well-acclimatized climber can effectively walk to the summit. This masks how serious Aconcagua is in practice. The mountain’s combination of 6,961m altitude, the notorious Viento Blanco (white wind) that can bring summit temperatures to -40°F even in January, and weather that changes faster than most climbers anticipate makes it genuinely dangerous. Aconcagua kills climbers every year — typically 3-5 per season, mostly from altitude mismanagement, exposure, or falls on the descent.

For climbers pursuing the Seven Summits or progressing toward Denali and Everest, Aconcagua serves as the critical altitude test. A successful Aconcagua summit demonstrates the ability to function effectively above 6,000m — the prerequisite experience for any harder high-altitude objective. Expeditions run 18-21 days total, with costs of $4,000-$10,000 for commercial trips. The more remote Polish Glacier route offers a quieter experience with similar difficulty, and the Vacas Valley approach provides a scenic alternative to the busy Horcones Valley.

Ojos del Salado is the second-highest peak in the Andes and the highest volcano in the world. Straddling the Chile-Argentina border in the Puna de Atacama — the driest non-polar region on earth — Ojos sits in a landscape so arid and otherworldly it has been used by NASA as a Mars-analog environment. The mountain was first climbed on February 26, 1937 by Polish climbers Jan Alfred Szczepański and Justyn Wojsznis during a Polish Andean expedition.

The standard Chilean Normal Route from the Refugio Atacama is the classic way up — a non-technical walk-up that climbers can ascend without ropes, crampons, or glacier experience in most years. The exception is the short rocky summit block that typically requires 10-20 meters of scrambling (Class 3-4) and a fixed rope. From base camp at 5,200m, climbers typically push to high camp at 5,850m, then to the summit in 8-12 hours round trip. Success rates run 60-70%, higher than Aconcagua, primarily because Ojos has far less weather complexity and vehicle access to remarkable altitude.

What makes Ojos del Salado famous among driving enthusiasts is that its approach road holds the world record for the highest altitude reached by a production vehicle — 6,688m in 2020. The combination of drivable 6,000m+ altitude, straightforward climbing, and surreal Atacama scenery has made Ojos a popular alternative to Aconcagua for climbers seeking extreme altitude without the Aconcagua crowds. Expeditions run 10-14 days and cost $3,000-$6,000 including vehicle logistics.

Huascarán is the highest peak in Peru, the highest peak in the tropics worldwide, and the crown of the Cordillera Blanca — the world’s most glaciated tropical mountain range. The mountain has two main summits: Huascarán Sur (6,768m, the true summit) and Huascarán Norte (6,655m). It was first climbed on July 20, 1932 by a combined German-Austrian expedition of Philipp Borchers, Wilhelm Bernard, Erwin Hein, Hermann Hoerlin, Erwin Schneider, and Austrian climber Egon Bock reaching Huascarán Sur.

The standard route from the Huaraz-area town of Musho ascends the Garganta (the col between the two summits) via steep glacier travel, significant crevasse hazard, and exposed upper slopes. Huascarán is rated PD+ to AD depending on conditions — technically moderate but with substantial objective hazard. The 1970 Ancash earthquake triggered a massive ice-and-rock avalanche from Huascarán that buried the town of Yungay and killed over 20,000 people, remaining the deadliest single natural disaster in South American history. This history underscores the mountain’s inherent instability.

Modern Huascarán expeditions run 12-15 days from arrival in Huaraz, including acclimatization climbs on smaller Cordillera Blanca peaks. Success rates run 40-50%, suppressed by weather and the mountain’s technical demands. For climbers seeking the complete Peruvian alpine experience — trekking through villages, acclimatizing on 5,000m peaks, then attempting the cordillera’s highest — Huascarán is the culminating objective. Costs run $2,500-$5,000 for guided expeditions.

Sajama is the highest peak in Bolivia — a perfectly shaped, extinct stratovolcano rising nearly 2,500 meters in dramatic isolation from the Bolivian altiplano. Located in Sajama National Park near the Chilean border, the mountain was first climbed on October 7, 1939 by Wilfrid Kühm and Joseph Prem of a German expedition, though there is evidence of pre-Columbian ascents — Sajama holds some of the highest archaeological sites on earth, with Inca ceremonial remains found near its summit.

The standard route from the village of Sajama (4,200m) involves a multi-day approach, a high camp at around 5,700m, and a summit push through steep snow slopes and a penitentes-covered upper face. The route is rated PD+ to AD-, with the main challenge being the mountain’s unique penitentes — the distinctive blade-shaped ice formations that cover Sajama’s upper slopes and make navigation in whiteout conditions genuinely difficult. These ice blades can be chest-high and create a terrain that resembles no other climb on earth.

For climbers visiting Bolivia, Sajama is often attempted as a standalone objective rather than paired with Illimani — the two mountains are in different regions of the country and require separate approaches. Sajama National Park offers wild, undeveloped climbing with minimal guide infrastructure and extraordinary scenery including flamingo-filled lakes, thermal hot springs, and vicuña herds. Expeditions run 7-10 days from La Paz and cost $1,500-$3,000 including transport and permits.

Illimani is the iconic mountain of Bolivia’s capital, La Paz — visible from virtually every part of the city, its five-peaked summit ridge dominating the eastern skyline. The mountain was first climbed on September 10, 1898 by a British expedition led by Sir Martin Conway with Swiss guides Antoine Maquignaz and Louis Pellissier. Illimani has four named summit peaks; the highest (Pico Sur) is the main objective for most modern climbers.

The standard Nido de Cóndores Route from the village of Pinaya ascends steep glaciated terrain to a high camp at 5,400m, then climbs the upper west face and summit ridge. The climb is rated PD+ with sustained snow and ice sections, exposed ridge traverses, and significant crevasse hazard on the Illimani glacier. Summit days typically run 10-14 hours round trip from high camp, with most parties leaving at midnight to reach the summit at sunrise before afternoon weather deteriorates.

What makes Illimani unique in the Andes is its accessibility-to-seriousness ratio. La Paz’s altitude (3,640m) provides instant partial acclimatization. The approach to base camp takes only 3-4 days. Yet the mountain itself is a genuine 6,400m+ glaciated peak with real technical challenge. For climbers with limited time seeking substantial Andean experience, Illimani offers the most efficient path — most full expeditions run 6-8 days from La Paz. Costs of $1,500-$2,500 reflect Bolivia’s overall value proposition for high-altitude climbing.

Chimborazo is Ecuador’s highest peak and geographically the farthest point on Earth’s surface from the planet’s center. Because Earth bulges at the equator, Chimborazo’s summit — sitting at 1°28′ South latitude — extends approximately 2,168 meters farther from Earth’s center than Mount Everest’s summit. By this measure, Chimborazo is the “closest point to the sun” despite being almost 2,600 meters shorter than Everest. It was first summited on January 4, 1880 by Edward Whymper (of Matterhorn fame) with guides Jean-Antoine Carrel and Louis Carrel.

The standard Whymper Route from the Carrel Refuge at 4,850m ascends the mountain’s north side via steep glaciated terrain, including the notorious “El Castillo” section and the summit glacier. The climb is rated PD to PD+ — technically moderate but requiring genuine glacier travel skills, crampon proficiency, and the ability to handle steep snow slopes at altitude. Summit days run 8-12 hours round trip from the refuge, typically starting at midnight to reach the summit before afternoon cloud buildup.

Chimborazo serves as the capstone of the Ecuador training circuit — the peak most commonly attempted as the final objective in a multi-peak Ecuadorian trip. A successful Chimborazo summit, following acclimatization on Cayambe and Cotopaxi, demonstrates readiness for harder objectives like Aconcagua or Denali. Climate change has significantly affected Chimborazo in recent years — glacial retreat has altered the standard route, and the mountain now requires more technical skills than it did a decade ago. Expeditions run 2-3 days from base Ecuador logistics and cost $1,000-$2,000.

Alpamayo was famously named “the most beautiful mountain in the world” in a 1966 survey of climbing magazine readers — a reputation built entirely on its striking fluted ice faces rising to a near-perfect pyramid summit. The mountain is shorter than most entries on this list but technically harder than all of them. Alpamayo was first summited on June 20, 1957 by German climbers Günter Hauser, Bernhard Huhn, Frieder Knauss, and Horst Wiedmann on the north ridge.

The classic modern route is the Ferrari Route on the Southwest Face, first climbed in 1975 and now considered the standard objective. The route is rated AD+ to D and involves sustained 60-degree ice climbing on exposed flutings, with technical pitches at TD difficulty in poor conditions. Alpamayo is not a peak for climbers learning glacier travel — it is a peak for experienced alpinists who have completed PD and AD-grade climbs elsewhere and want to step into technical ice climbing at altitude.

The approach from Cashapampa to the Alpamayo base camp takes 2-3 days of trekking through the stunning Santa Cruz valley, making the trip itself a highlight even before the climb begins. Full expeditions run 10-14 days from Huaraz with extensive acclimatization on neighboring peaks like Ishinca and Urus. Costs of $3,000-$5,000 reflect the technical nature of the climb — guided parties require a high-ratio guide-to-client arrangement (typically 1:2 maximum). Summit success rates run 30-40% across the season, strongly weather-dependent.

Cotopaxi is one of the highest active volcanoes in the world and Ecuador’s most iconic mountain — a nearly perfect snow-covered cone rising from the central Ecuadorian highlands. Visible from Quito on clear days, Cotopaxi has become the standard “first high-altitude peak” for climbers entering South American mountaineering. It was first climbed on November 28, 1872 by German geologist Wilhelm Reiss and his Colombian companion Ángel Escobar.

The standard route from the José Rivas refuge at 4,864m involves crossing the Cotopaxi glacier with moderate snow slopes to the summit — a classic non-technical glaciated climb that introduces every essential Andean skill: crampon technique, rope travel on glaciers, basic crevasse awareness, and altitude management. The climb is rated PD with typical summit days of 6-10 hours round trip. Because the refuge is reached by road and the approach is short, Cotopaxi can be climbed on a 2-day schedule from Quito — rare among 5,800m+ peaks anywhere.

Cotopaxi’s status as an active volcano adds complexity. The mountain erupted in 2015 and has had multiple activity episodes since; climbing has been closed or restricted several times in recent years. Before booking, verify current access status — Ecuadorian authorities can close the mountain with little notice when seismic activity increases. When open, Cotopaxi is the best-value entry point to high-altitude Andean mountaineering anywhere, with guided costs of just $800-$1,500 for a 2-day package including refuge overnight.