Uninhabited Regions of South America: Amazon, Andes, Atacama

Where People Don't Live in South America — And Why

Despite South America's 430+ million people, vast regions remain sparsely populated due to extreme environmental conditions. Three major zones stand out:

1. The Amazon Rainforest

Scale: 5.5+ million km² across 9 countries (60% in Brazil)

Population Density: <1 person/km² in interior

Barriers to Settlement:

• Climate: Hot (25°C avg), humid, 2,000-3,000 mm annual rainfall
• Disease: Malaria, yellow fever, dengue, Chagas, parasitic infections
• Soil: Nutrient-poor lateritic soils (oxisols) — agriculture fails without inputs
• Fauna: Venomous snakes, jaguars, insects, waterborne parasites
• Access: No roads in vast areas; river transport only

Inhabitants: Primarily Indigenous peoples (Yanomami, Kayapó, Asháninka, hundreds of groups) with traditional adaptations; some rubber tappers, miners, researchers.

2. The Andes Mountains

Scale: 7,000+ km length, up to 6,961 m (Aconcagua)

Population Density: Very low above 3,500 m; moderate in intermontane valleys

Barriers:

• Altitude: Hypoxia (low oxygen), cold (10°C avg), intense UV radiation
• Geohazards: Earthquakes, volcanic eruptions, landslides, avalanches, glacial lake outbursts
• Agriculture: Limited to hardy crops (potatoes, quinoa, barley) and camelid pastoralism
• Infrastructure: Extremely costly; passes often closed by snow

Inhabitants: Quechua, Aymara, and other Indigenous highland peoples with genetic/physiological adaptations (larger chests, higher hemoglobin); miners at major deposits (Cerro de Pasco, Potosí, Chuquicamata).

3. The Atacama Desert

Scale: 105,000 km² (northern Chile, parts of Peru/Bolivia/Argentina)

Population Density: <0.1 person/km² in core

Barriers:

• Aridity: <1 mm/year rainfall in core; some weather stations never recorded rain
• Temperature: 25°C avg but extreme diurnal swings; freezing nights
• Water: Virtually none — no permanent rivers, minimal groundwater
• Soil: Saline, nitrate-rich, sterile
• Fauna: Scorpions, spiders, extremophile microbes

Inhabitants: Copper miners (Chuquicamata, Escondida, Collahuasi), astronomers (ALMA, Paranal observatories), tourism workers (San Pedro de Atacama), few Indigenous Atacameños/Lickanantay.

Common Thread: Indigenous Adaptation

In all three regions, the few permanent residents are predominantly Indigenous peoples with millennia of cultural, physiological, and technological adaptation. Modern resource extraction (mining, oil, hydro) creates temporary non-Indigenous populations in company towns.