Hundreds of years before the Inca road system connected a sprawling empire, a more modest network of trails linked the small communities that lined the mountains and coastlines of South America. These trails, snaking through the Andes, supported a vibrant network of llama caravans, which may have been the driving force behind elements of cultural continuity that have been shared by different South American societies for the last millennium—and perhaps even longer.

“These caravanners were the lubricant for more than just trade goods,” says Nicholas Tripcevich , a research associate and lab manager at the University of California, Berkeley. “They served an important role linking people. They probably spread information, stories.”

Caravans have moved goods and news across deserts and mountains by donkey, mule and camel throughout the history of civilization. The role these merchants played in Arabia and Europe in centuries past is well known, but nomadic traders also connected ancient South American cities and civilizations. While traveling vendors in other parts of the world may have used horses or wagons to transport goods, the caravans of South America made use of llamas and alpacas, native to the area and built for mountainous terrain.

The first evidence in the Andean region of caravans using camelid species, including llamas and the woollier alpacas, dates to around 3,000 years ago. Traces of ancient trails and scattered archaeological deposits have been discovered in modern Chile, south of the Atacama Desert. But our knowledge of South American caravanners is limited, largely due to the fact that the itinerant nomads left little trace of their presence in the archaeological record other than hints of the weather-worn trails they followed.

However, a new analysis of rock art depicting caravans found in a rocky outcropping above a valley in northern Chile, as well as the bones of llamas whose meat may have been offered in ritual sacrifice, reveals a snapshot of the hidden ceremonial lives of these elusive traders. The caravanners, who offered one of the only ways to communicate across great distances, may have held disparate communities together during a period of instability about 900 years ago.

“The caravanners were grand cultural connectors in the Andes,” says Daniela Valenzuela, an anthropology professor at the University of Tarapacá in Chile and lead author of a study published recently in Quaternary International that analyzes the caravan site in Chile. She compares the South American llama drivers who stopped at the site, known as Cruces de Molinos, to the caravan traditions of other parts of the world.

The caravan travelers who drew the rock art and left offerings at Cruces de Molinos were likely alive during a period that lasted several centuries with no major regional empires. Earlier cultures like the Tiwanaku, which controlled parts of modern-day Bolivia, northern Chile and Peru, had abruptly collapsed by about 1000 AD. The Inca, for their part, began to muster strength in the 13 th century but didn’t arrive in northern Chile until about 1400.

While these larger empires had the resources to move trade goods, sometimes paid as tribute, Valenzuela says that the period between these major empires was characterized by smaller communities without the reach of the Inca or Tiwanaku. As a result, caravans must have played a critical role moving goods between the coasts, fertile valleys and highlands.

“They traded ch’arki , meat, textiles or wool, and they exchanged highland items with maize, fish and coastal items like guano to fertilize the plants,” Valenzuela says. ( Ch’arki is a Quechua word for dried meat, later anglicized as “jerky.”)

The Cruces de Molinos site sits above the Valley of Lluta and a small town, on the border of the lush pastures of the highlands where llamas and alpacas would have had plenty of water and grass. Valenzuela says that the fact that the area marked a transition between climates and ecological zones may have also been why the caravanners chose the spot to make ceremonial offerings.

Valenzuela discovered the rock art while doing a survey in 2000 as part of her bachelor’s thesis. While she found about 10 different sites with rock art, she says that Cruces de Molinos, about 500 feet above the valley floor, is the most elaborate. The art, which was likely made between 950 and 1400 AD, depicts a number of different scenes, including people leading camelids along by a rope or string. Some parts of the illustrations also depict the large, ostrich-like rhea, which often shares pastures with camelids in the area.

“We suppose these images represent the caravanners’ desires,” she says, adding that they may have been a wish for safe journeys and good trade. Meanwhile, nearby camelid bones dating from 1060 to 1190 AD show cut marks and cross sections of animal parts, indicating the meat was likely butchered and prepared as jerky.

While these remains may represent a cache of food stored for later times, Valenzuela believes their placement beneath an engraved block of stone indicates that they were left as a type of spiritual offering, possibly to Pachamama—a goddess who represents concepts like earth, time and fertility. The suspected offering of llama meat, along with the rock art and the high, relatively inaccessible placement of the site all indicate that this area was used as a ceremonial pit stop. Caravan traders may have departed from nearby trade routes, whose traces can still be seen on the landscape, to make offerings and perform rituals before embarking on the next leg of their journey.

Tripcevich, who was not involved in the new research, has worked with contemporary caravanners in South America. In 2007, he followed a caravan through Peru for two weeks to learn more about long distance travel strategies. The caravan, which hadn’t traveled this route since 1994 when new roads were built, loaded up on salt from the mines around Cotahuasi on the coast of Peru and transported it nearly 150 miles to the Apurimac area to the north. While there is some cultural continuity between the ancient and the modern caravanners, Tripcevich says he isn’t sure today’s caravanners descend directly from the people who left rock art and offerings at Cruces de Molinos.

Rather than leaving jerky or other meat offerings, contemporary ceremonies he witnessed on the route included the caravan leaders giving their llamas chicha, a maize-based beer, to increase the feeling of camaraderie between humans and animals for the road to come. They also made offerings of harder alcohol to the Pachamama, as well as conducting some rituals of Catholic influence.

Tripcevich says this sense of togetherness seems to differ from the ancient caravanners. He finds it intriguing and a bit perplexing that the rock art in Cruces de Molinos depicts humans leading animals with a type of string. In his experience with modern caravans, the llamas more or less lead the way without a rope, and the most experienced and trusted animals take the initiative when fording rivers and crossing rough terrain.

It’s possible that modern-day caravanners descended culturally from the ancient people who practiced this art, Valenzuela says, but the practices and ceremonies likely changed drastically after the arrival of the Europeans. “During colonization, the Spaniards were concerned about religion [and] evangelization. So in traditional beliefs there are many changes,” she says.

Although llama and alpaca caravans still operate today in remote parts of the Andes, Tripcevich says the practice is disappearing. Chile placed landmines along its northern border near the Cruces de Molinos site during the dictatorship of Augusto Pinochet in the 1970s and 1980s, which deterred the caravanners who used routes in that area. In Peru, the caravans persisted despite the civil war of the 1980s, when the Maoist Shining Path guerillas controlled much of the highlands. During the violence and instability of the time, the caravans offered alternative means for moving goods between remote parts of the country using pre-Columbian routes. But after the end of the war brought development and roads into some of these regions, Tripcevich says that the caravanners couldn’t compete with trucks.

Nonetheless, the practice has shown a great degree of resiliency throughout history. According to Valenzuela, conditions for caravanners during the Cruces de Molinos period were likely not stable either. While no major empires controlled this part of the Andes, many of the cities at this time were characterized by major fortifications, likely indications of war and social tension. The Inca may have even modified and incorporated some caravan routes into their roads once they took control of the western part of the continent.

According to Tripcevich, young South Americans aren’t as interested in continuing this ancient way of life. But then again, the practice has survived multiple empires, Spanish Colonization and more recent dictatorships and civil wars. Llamas can essentially be maintained for nothing, as they feed on grass in open ranges. As a result, jumps in gas prices brought back the ancient practice of caravanning during some periods, and Tripcevich wouldn’t be surprised if the llamas bounce back again.

“The animals are certainly still there. It’s very low cost,” he says. “[The caravans] could come back.”