San Guillermo National Park

The San Guillermo National Park (in Spanish: Parque Nacional San Guillermo) hosts a mighty array of wildlife. This park, declared a UNESCO Biosphere Reserve, is a call to adventure for nature enthusiasts and those seeking refuge from the hustle and bustle of the modern world.

National Park Data

San Guillermo National Park

Geographical Location

Situated in the province of San Juan within the Cuyo region, the park lies at the foot of the towering Andes Mountain Range, harboring a landscape that stretches from high summits to vast mountain steppes. It can be pinpointed geographically using the coordinates: 29°06′S 69°12′W / -29.1, -69.2.

Historical Background

Before being known as the San Guillermo National Park (in Spanish: Parque Nacional San Guillermo), this area was designated as a Provincial Reserve in 1972. However, in 1997, the government of the San Juan province decided to transfer the territory to the National Parks Administration. It was on December 9, 1998, that the park was officially authorized to open its doors to tourists. The region holds evidence of human occupation dating back around 10,000 years. In the late 16th century, the Inca Empire invaded, and the San Guillermo plain was utilized for the exploitation of vicuña wool.

In this context, the province of San Juan enacted Law No. 4164 on December 23, 1975, declaring the "Estancia de San Guillermo" field as of public utility subject to expropriation. The aim of this action was to protect the vicuñas and establish the San Guillermo Provincial Nature Reserve. However, Provincial Law No. 5949, passed on February 6, 1989, repealed Law No. 4164. Nevertheless, on March 8, 1989, the provincial Legislature rectified this law, excluding only 125,680 hectares from the declaration of public utility for the provincial nature reserve.

These steps in the park’s previous history paved the way for its recognition as a nationally protected area and its subsequent opening for the enjoyment of tourists interested in exploring its impressive natural beauty and rich biodiversity.

Park History

Established on January 13, 1999, through Law No. 25,077/98, with the primary aim of preserving the region’s biodiversity and promoting scientific research, it holds the status of a National Park and a Biosphere Reserve.

The process of creating and legislating the San Guillermo National Park took place through agreements and laws both at the provincial and national levels. On October 11, 1996, the province of San Juan and the national government signed an agreement that was approved through provincial decree No. 1469/1996. This agreement stipulated that the province would transfer the ownership and jurisdiction over a portion of the San Guillermo provincial park, covering an approximate area of 170,000 hectares, while another adjacent sector would be designated as a buffer zone under provincial jurisdiction.

The governor of San Juan ratified the agreement through decree No. 1469/1996, dated October 18, 1996, and it was subsequently approved by the San Juan Legislature through Law No. 6788, enacted on February 13, 1997, and promulgated on February 26, 1997.

At the national level, Law No. 25,077, enacted on December 9, 1998, and effectively promulgated on January 13, 1999, approved the agreement between the province of San Juan and the national government and officially declared the creation of the San Guillermo National Park. This law established the legal framework for its recognition and protection as a nationally significant nature reserve.

These processes of legislation at both the provincial and national levels were instrumental in establishing the official status of the National Park and ensuring its long-term conservation and protection.

Ecological Importance and Biodiversity

The park serves as a vital refuge for several endangered species, such as the Andean puma and the guanaco. It harbors a tremendous diversity of flora and fauna adapted to the harsh conditions of the high mountains.

Geographical Features

Landscape Description

Located in the Monte de Sierras y Bolsones, Puna, and High Andes Ecoregion, the park’s landscape comprises an area of 166,000 hectares of towering mountains, vast valleys, mountain streams, and the striking beauty of the mountain steppe. The varied topography offers an incredible array of natural settings.

Geology and Topography

With the backdrop of the Andes Mountain Range, the park presents diverse geology, with altitudes ranging from 2000 to 6000 meters above sea level. It is an area of intense geological activity, featuring impressive rock formations and a wealth of minerals and fossils.

Climate of the Region

The climate in San Guillermo National Park is cold and dry, characterized by significant daily temperature fluctuations.

During the summer, average temperatures reach 15°C, but minimums can drop below 0°C.

In winter, average temperatures are around 1°C, with minimums plummeting to -15°C. Annual precipitation ranges from 30 to 100 mm, with torrential rains during the summer season and frequent snowfall during the colder months. Winds are strong, with gusts exceeding 120 km/h.

Biodiversity and Ecosystems


San Guillermo National Park safeguards a significant portion of the Puna ecoregion, located in the southernmost region of Argentina. This ecoregion is characterized by high altitudes, with an average elevation of nearly 4,000 meters within the protected area. Altitude is a determining factor for life in this ecosystem, as the extreme conditions of altitude, such as low oxygen pressure and low temperatures, influence the distribution of flora and fauna.

The park also protects a portion of the High Andes ecoregion, which includes the Monte de Sierras y Bolsones. This region is marked by rugged topography, with interspersed mountains and valleys, creating a great diversity of landscapes. The contrast between the high peaks of the Andes and the lower valleys creates a unique scenario where different ecosystems and habitats coexist.

The combination of the Puna and High Andes ecoregions within San Guillermo National Park results in a remarkable biological diversity. Despite the harsh environmental conditions, the protected area hosts a variety of species adapted to life in the high mountains. Prominent fauna include the Andean puma, guanaco, Andean condor, and vicuña, all finding refuge in this ecosystem.

Regarding flora, species adapted to extreme conditions can be found, such as high-altitude cacti, resilient shrubs, and alpine and subalpine plant species. These plants have developed strategies to survive in nutrient-poor soils and a climate marked by cold winters and mild summers, with scarce precipitation.

Iconic Species

The vicuña (Vicugna vicugna) has historically been an emblem of San Guillermo National Park. These elegant camelids have always been abundant on the high plains. For 6,500 years, human activities have demonstrated the relationship and interest that existed for these animals. Currently, vicuña populations are in the process of recovery after a significant decline due to a mange outbreak.

The vicuña’s body is adapted to the rigorous environment of the High Andes and the Puna. Its coat consists of two layers of wool that protect it from intense cold, and its coloration blends with the landscape, camouflaging it from predators like the puma. The vicuña can reach speeds of up to 47 km/h when running.

Distinctive Flora

The flora of San Guillermo National Park is characterized by its adaptation to the harsh conditions of the high mountains. Low and compact vegetation species dominate, such as "yaretas" and the San Guillermo daisy (Huarpea andina), which is exclusive to this protected area. These plants display remarkable resistance to water scarcity and low temperatures.

In certain areas of the park where moisture accumulates, "vegas" are formed. These areas exhibit a remarkable green coloration due to a higher concentration of plants. Vegas are places where water is more abundant, allowing for a diversity of plant species.

The combination of low, compact vegetation and vegas creates a contrasting landscape in San Guillermo, providing habitat for a variety of species adapted to these extreme conditions of the high mountains.

Present Fauna in the National Park

It is the habitat of a wide variety of wildlife adapted to the extreme conditions of the high mountains. In the summer meadows and streams, numerous representatives of the local fauna can be found. Among them, red foxes and colorful flocks of Andean goldfinches come to drink water. Lizards like the San Guillermo chelco and the cola piche bask on the rocks, while mountain vizcachas or chinchillones make their homes among them.

However, the true stars of the park are the vicuñas. These graceful native camelids roam in large groups across the plains, especially in the area known as the Llano de los Leones. San Guillermo hosts one of the highest concentrations of vicuñas, whose populations have experienced a significant recovery after being endangered.

The presence of these iconic species, such as the vicuñas, reflects the importance of protecting the environment and ensuring its viability as a refuge for wildlife conservation in the high mountain region. Observing these species in their natural habitat is a remarkable experience for park visitors.

Cultural Aspects

Indigenous Groups and Their Relationship with the Park

The park has a rich cultural history that dates back thousands of years. The first inhabitants of the region were indigenous groups like the Diaguitas and Huarpes, who left an important cultural legacy in the region.

Its extreme cultural landscape tells the vast history of valuation and uses by various groups over time, from hunter-gatherers and agricultural communities to the arrival of the Spanish and the Creole. However, what has remained constant over time is its extreme condition: rigorous weather with great temperature fluctuations, a high-altitude landscape above 3,400 meters above sea level, and access routes conditioned by seasonal weather, making planning a visit an additional challenge.

Historical and Cultural Influences

Throughout the centuries, the region has been influenced by various cultures and civilizations, leaving behind a cultural legacy that can be appreciated today in the form of historical artifacts, legends, and traditions.

Recommended Activities

Visiting San Guillermo National Park is primarily done by vehicle due to the high altitude above sea level and the importance of ensuring visitor safety. The park offers two approved routes:

Panoramic Point Circuit

This route starts by heading north from the Agua del Godo Operations Center. The main road is left to the east to reach a viewpoint situated at 3,760 meters above sea level, in the Llano de Los Leones. From this point, you can contemplate the imposing presence of Cerro Imán to the west, as well as observe groups of vicuñas and guanacos in activity. It’s an ideal spot for enjoying panoramic views and appreciating wildlife in its natural environment.

Caserones Circuit

This circuit, approximately 5 kilometers in length, starts by heading south from the Agua del Godo Operations Center. After crossing the San Guillermo River gorge, a detour is taken to the west, passing near the base of Cerro Potosí, to reach the Caserones meadow. In this area, you can observe a granite outcrop with rounded shapes, where the La Cueva Stream flows, descending from Cerro Imán. Additionally, you can take a walking route of about 350 meters, walking among old corrals, and enjoy an impressive panoramic view of the outcrop.

These two circuits allow visitors to appreciate the natural beauty and impressive landscapes of San Guillermo National Park, as well as provide the opportunity to observe wildlife in its natural habitat. It’s important to follow the instructions and respect the park rules to ensure the conservation of the environment and enjoy a safe experience.

Conservation and Sustainability

Threats and Challenges

Despite its protected status, the park faces various challenges, including climate change, poaching, and overgrazing. The participation of everyone is essential to ensure its long-term conservation.

Ongoing Conservation Projects

Several ongoing conservation projects exist, including wildlife monitoring programs, habitat restoration, and environmental education. These efforts are crucial to maintain the ecological health of the park.

How to Get There

To reach San Guillermo National Park from the city of San Juan, you need to take RN 40 and then RN 150 towards the town of Rodeo, which is about 195 km away. The Park’s Intendancy is located in Rodeo, where the necessary arrangements for the planned visit should be made in advance.

At the Intendancy, visitors must provide their personal documentation and vehicle information, as well as relevant medical records. Additionally, an entry registration will be conducted. It’s important to remember that, to access the Park, it’s mandatory to be accompanied by an authorized tourist guide or to arrange the visit with an authorized tour operator.

From the Intendancy, the journey to the Park entrance takes approximately 5 hours. You’ll travel along RP 430, crossing the Blanco River twice. The road goes through different towns such as Angualasto, Malimán, and El Chinguillo, with the latter being the last inhabited area before entering the protected zone. From there, you’ll travel an additional 95 km, roughly 3 hours, until you reach the entrance to the Quebrada de la Alcaparrosa, which is the southern entrance to the Park and is situated at an altitude of 2300 meters above sea level.

To access the Llano de San Guillermo, located at an altitude of 3400 meters above sea level, and reach the mountain refuge at the Agua del Godo Operations Center, you need to continue the journey for about 2 more hours. It’s important to consider that during this part of the trip, you’ll traverse roads with varying widths and steep inclines, so it’s necessary to use four-wheel-drive vehicles. Additionally, it’s recommended that the driver has the necessary knowledge and experience to ensure a safe journey on these routes.

Resources for Planning Your Visit

Best Time to Visit

It’s recommended to visit San Guillermo National Park during the autumn and spring seasons. In summer, rains and mountain thaws can hinder access and create adverse conditions. During autumn and spring, temperatures are milder and the intense rainy season is avoided. These seasons offer more favorable conditions to enjoy the natural beauty of the park and engage in outdoor activities safely.

Recommended Time for a Complete Visit

Planning a stay of at least two days in the park, including overnighting, is suggested. This recommendation is due to both the altitude of the area, which may require adaptation time, and the opportunity to leisurely enjoy activities and contemplate the stunning landscapes in all their grandeur. Taking enough time will allow you to fully immerse yourself in the experience and appreciate the natural beauty the protected area offers.

Requirement to be Accompanied by a Tour Guide

It’s important to highlight that entering San Guillermo National Park requires being accompanied by an authorized Tourist Guide. This measure aims to ensure the safety and conservation of the park, as well as to provide an enriching experience for visitors. The cost of hiring a guide is the responsibility of the visitor.

Visit Price

Access is free, but it’s mandatory to enter accompanied by an authorized Tourist Guide. The hiring of the guide is private, and the cost is covered by the visitor.

Where to Stay When Visiting San Guillermo

The Agua del Godo Operations Center in San Guillermo National Park offers accommodation services for visitors. This center consists of a group of buildings that include a lodging area with a capacity for twelve people, as well as a kitchen-dining area and restrooms. However, it’s important to note that items such as sleeping bags and cooking utensils are not provided. Reservations must be made in advance and are subject to availability. In case another group has already made a reservation, you’ll need to reschedule your visit.

The use of the facilities at the Agua del Godo Operations Center is free, but it’s necessary to bring the necessary firewood for heating or using the barbecue area from the town of Rodeo. It’s recommended to plan ahead and bring all the necessary items for a comfortable and safe stay at the lodging center.

Keep in mind that services and conditions may be subject to changes, so it’s recommended to verify updated information when making the reservation and when planning your visit.

Visitor Rules and Regulations

Visitors must adhere to the park’s rules and regulations to ensure its conservation. This includes not littering, not feeding animals, and staying on designated trails. The golden rule is "Leave only footprints, take only memories."

Contact and Information

For updated information about the park, you can get in touch with the visitor center. Here, you’ll receive details about hours, regulations, and helpful tips for your visit.

Intendancy of San Guillermo National Park

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