Eduardo Avaroa Andean Fauna National Reserve: The Red Lagoon

The Eduardo Avaroa Andean Fauna National Reserve (Reserva Nacional de Fauna Andina Eduardo Avaroa) lies in the extreme, isolated southwest corner of Bolivia, bordering the high deserts of Chile and Argentina. Covering 7,147 square kilometers at elevations between 4,200 and 5,400 meters, it is one of the most hostile and visually striking environments on the planet—a volcanic plateau where blood-red lakes, pink flamingos, and active geysers coexist in conditions barely compatible with life.

Sitting at punishing altitudes that range between 4,200 and 5,400 meters (13,800 to 17,700 feet) above sea level, this vast, high-altitude desert (the Altiplano) is not a place for the faint of heart. It is a raw, volcanic landscape defined by freezing, hurricane-force winds, bubbling geothermal geysers, steaming high-altitude hot springs, and bizarre, mineral-dyed lakes filled with tens of thousands of vibrant pink flamingos.

While the reserve is a spectacular destination in its own right, it is most famous globally as the dramatic, colorful climax of the classic 3-to-4-day 4x4 jeep tours that cross the neighboring Salar de Uyuni (the world’s largest salt flat). A journey through Eduardo Avaroa is a journey to the absolute limits of where life can survive.

Geological History: A Canvas of Minerals and Ice

The dramatic topography of the Eduardo Avaroa Reserve was forged by the violent tectonic collision of the Nazca Plate subducting beneath the South American Plate. This ongoing collision uplifted the massive Andes mountain range and created the Altiplano—a vast, high-altitude plateau that is the second most extensive on Earth (after Tibet).

The Ring of Fire

The reserve is dotted with towering, often snow-capped stratovolcanoes, many of which are still active. The most prominent is the perfectly conical Licancabur Volcano (5,920 meters), which straddles the border with Chile. The intense geothermal activity just beneath the Earth’s crust drives the spectacular Sol de Mañana geyser basin, where boiling mud pots and pressurized steam vents hiss violently into the freezing morning air.

The Colored Lakes

The reserve’s most famous features are its vividly colored lagoons, which lie in closed, high-altitude basins where water can only escape through evaporation. Because the evaporation rate in this arid desert is intensely high, the remaining water becomes hypersaline (saltier than the ocean) and heavily concentrated with volcanic minerals like borax, sulfur, and arsenic.

The bizarre colors of these lakes—ranging from blood red to emerald green to pale blue—are caused by specific combinations of these suspended minerals reacting to sunlight, as well as the specialized, extremophile algae and bacteria that manage to thrive in the toxic, salty water.

Wind Erosion

In the Siloli Desert section of the reserve, the constant, fierce, sand-carrying winds have acted like a giant sandblaster over millions of years, carving relatively soft volcanic ignimbrite rock into surreal, gravity-defying shapes.

Wildlife & Biodiversity: Survival in the Death Zone

It seems impossible that anything could survive in a landscape with virtually no rainfall, freezing nightly temperatures, fierce winds, intense UV radiation, and half the oxygen of sea level. Yet, the Eduardo Avaroa Reserve protects a highly specialized and fragile ecosystem.

The Flamingos of the High Andes

The defining image of the reserve is the surreal sight of bright pink flamingos wading through freezing, toxic, brightly colored water against a backdrop of snow-capped volcanoes. The reserve hosts three of the world’s six flamingo species:

1. The Andean Flamingo: One of the rarest flamingos in the world, distinguished by its pale pink body, black wingtips, and yellow legs.
2. The Chilean Flamingo: Widespread across South America, noted for its grayish legs with bright pink “knees” (joints).
3. The James’s Flamingo (Puna Flamingo): This species is so incredibly rare and specialized to the high Altiplano that it was actually declared extinct in 1924, only to be dramatically rediscovered living in Laguna Colorada in 1956.

These birds survive by using their specialized, downward-curving bills to filter feed on the microscopic cyanobacteria and diatoms (algae) that give the lakes their striking colors. The pigments in the algae are what turn the flamingos’ feathers pink.

Mammals of the Altiplano

• Vicuña: The elegant, wild ancestor of the domesticated alpaca. These graceful camelids possess some of the finest, warmest wool in the animal kingdom, allowing them to graze comfortably on the sparse ichu grass in freezing temperatures. They were heavily poached but are now protected and recovering.
• Viscacha: Often spotted sunning themselves on volcanic boulders, the viscacha looks like a bizarre cross between a rabbit and a chinchilla, sporting long ears and a long, curly tail.
• Andean Fox (Culpeo): This highly adaptable predator is frequently seen trotting near the edges of the lagoons or near tourist camps, scavenging for food.

Key Attractions

Exploring Eduardo Avaroa is done almost entirely by 4x4 Land Cruiser. There are no paved roads, and the distances between sights are vast.

1. Laguna Colorada (The Red Lagoon)

This 60-square-kilometer shallow salt lake is the most visited and visually striking feature of the reserve.

• The Spectacle: The water is a deep, striking blood-red color, caused by the pigmentation of a specific algae (Dunaliella salina) reacting to the intense high-altitude sunlight.
• The Contrast: Brilliant white, crusty islands of borax (a mineral salt) float on the red surface, creating a surreal contrast against the bright blue Andean sky. This lagoon is the primary nesting ground for the rare James’s Flamingo; at peak times, tens of thousands of pink birds dot the red water.

2. Laguna Verde (The Green Lake)

Located at the extreme southern edge of the reserve, right at the foot of the imposing Licancabur Volcano.

• The Color: The water here contains high concentrations of magnesium, calcium carbonate, lead, and arsenic. When the fierce afternoon winds whip up the mineral sediments from the lakebed, the water turns a brilliant, toxic emerald green. If you arrive early in the morning when the air is still, the lake often appears dull but perfectly mirrors the massive volcano behind it. (Note: Because of the high toxicity, flamingos do not inhabit Laguna Verde).

3. Sol de Mañana (Morning Sun Geyser Basin)

At an elevation of nearly 5,000 meters (16,400 feet), this geothermal field is the highest point most tourists will ever stand on.

• The Experience: Visitors usually arrive here at sunrise (when the air is coldest and the steam is most visible). The landscape is a violent, primitive expanse of boiling, plopping mud pots, fumaroles shooting pressurized steam 50 meters into the freezing air, and the overwhelming smell of sulfur.
• Warning: There are no safety rails or boardwalks here. The crust is thin, and stepping into a boiling mud pot is fatal. Walk carefully and only where your guide instructs.

4. Termas de Polques (Hot Springs)

After freezing in the jeep and at the geysers, these natural thermal pools offer incredible relief. Located on the edge of the Chalviri Lagoon, you can strip down to your swimsuit in sub-zero air temperatures and slide into 30°C (86°F) mineral-rich volcanic water while watching flamingos wade in the freezing lake just a few meters away.

5. Árbol de Piedra (The Stone Tree)

Located in the desolate Siloli Desert, this isolated volcanic rock formation has been eroded by centuries of wind and sand into the unmistakable shape of a stunted, 7-meter-tall tree growing directly out of the barren desert floor.

Seasonal Guide: Month by Month

The climate in the high Altiplano is extreme. There are only two distinct seasons: dry and wet.

• The Dry/Winter Season (May - October): The most popular time for the full circuit. The skies are brilliantly clear, piercing blue, and the views stretch for hundreds of miles. However, this is winter in the Southern Hemisphere. The daytime sun is intensely strong, but the nighttime temperatures drop to a brutal -15°C to -25°C (5°F to -13°F). The wind chill can be agonizing. You must pack extreme cold-weather gear.
• The Wet/Summer Season (December - March): The temperatures are slightly milder (nighttime lows around 0°C to -5°C). This is the season when the nearby Salar de Uyuni floods with a few inches of water, turning into the world’s largest, most spectacular mirror. However, heavy rains can wash out the dirt tracks inside the Eduardo Avaroa Reserve, sometimes making access to Laguna Colorada or Laguna Verde impossible.
• The Shoulder Seasons (April and November): Often the best compromise, offering milder temperatures than the dead of winter and less chance of rain than the peak summer.

Budget & Packing Tips

A trip to Eduardo Avaroa is usually a 3-day/2-night package booked in the town of Uyuni (Bolivia) or San Pedro de Atacama (Chile).

• Choosing a Tour Operator: The cheapest tours pack 6 passengers into a Land Cruiser and stay in freezing, basic refugios. Paying slightly more (a “mid-range” or “private” tour) gets you better food, a safer vehicle, an English-speaking guide, and often a private room.
• Accommodation in the Reserve: Standard tours stay in very basic, unheated cinderblock “refugios.” You sleep in your clothes inside a sleeping bag under thick alpaca blankets. Electricity is usually provided by a generator for only a few hours at night. There are a few luxury “Tayka” hotels built from salt or stone, but they must be booked on specialized luxury tours.
• The Essential Packing List:
  • Extreme Cold Gear: A heavy down jacket, thermal base layers, a warm hat (beanie), thick gloves, and wool socks are non-negotiable.
  • A Sleeping Bag: Rent a heavy-duty sleeping bag from your tour operator in Uyuni. You will need it in the unheated refugios.
  • Sun Protection: At 5,000 meters, there is very little atmosphere to block UV rays. You will burn rapidly. Bring high SPF sunscreen, lip balm with SPF, and excellent sunglasses (the glare off the salt and snow is blinding).
  • Toilet Paper and Hand Sanitizer: Facilities in the desert are rudimentary and rarely stocked.
  • Cash: Bring plenty of Bolivianos in small bills to pay the national park entrance fee (usually not included in the tour price), use the bathrooms, and buy snacks from remote villages.
  • Water: You must bring your own drinking water for the 3-day trip (usually 5 liters per person).

Frequently Asked Questions (FAQ)

Will I get altitude sickness?

It is highly likely you will feel the effects of the altitude. You will be sleeping at 4,300 meters and crossing passes near 5,000 meters. Symptoms include headaches, nausea, shortness of breath, and fatigue. Spend a few days acclimatizing in lower-altitude cities (like Sucre or La Paz) before taking the tour. Drink large amounts of water, avoid alcohol, eat light meals, and consider bringing altitude sickness medication (like Diamox) prescribed by your doctor. Chewing coca leaves or drinking coca tea is the traditional, legal, and effective local remedy.

Can I drive myself through the reserve?

Technically yes, but it is highly discouraged and extremely dangerous. There are no paved roads—only a chaotic web of deeply rutted jeep tracks crisscrossing the desert. There are no road signs, no cell phone reception, no gas stations, and GPS is notoriously unreliable here. A breakdown or wrong turn in this freezing, remote desert can quickly become a fatal emergency. Always hire an experienced local driver/guide.

What is the park entrance fee, and is it included in tour prices?

The entrance fee to Eduardo Avaroa is approximately 150 Bolivianos (around $20 USD) per person. It is frequently not included in the advertised tour price—confirm this before booking. You pay at the checkpoint near Laguna Colorada in cash only, so bring small bills in Bolivianos.

Can I visit just one or two sites rather than doing the full 3-day circuit?

Some operators in Uyuni offer day trips to the Salar and half-day extensions that reach only Laguna Colorada. However, the majority of the reserve’s highlights (Sol de Mañana, Laguna Verde, Termas de Polques) are only accessible as part of the multi-day circuit. Solo day access from the Chilean border at Hito Cajón is possible with your own 4x4.

Is the water in the colored lagoons safe to touch?

No. The water in Laguna Colorada and Laguna Verde is extremely toxic, heavily saturated with arsenic, borax, magnesium, and other volcanic minerals. Do not drink it, and avoid touching it unnecessarily to prevent skin irritation.

Are there any ATMs in the reserve?

There are none. Once you leave the town of Uyuni (or San Pedro de Atacama), you are completely cut off from the banking system. Bring all the cash you will need (in Bolivianos) for the full 3-day trip, in small bills.