A newly dated settlement at Lake Titicaca in Bolivia is pushing back the timeline of human life on the Island of the Sun by centuries, offering fresh evidence that people reached and used the high-altitude landscape far earlier than once thought.
The study, led by Charles Stanish of the University of South Florida and published in Latin American Antiquity, centers on Ch’uxuqullu, an archaeological site on the island’s northeastern side.
Researchers used new Accelerator Mass Spectrometry, or AMS, radiocarbon tests on samples excavated about 30 years ago. The results show the site was first occupied between 3635 BC and 3381 BC. That places the earliest known human presence there in the middle of the fourth millennium BC.
Ch’uxuqullu dates rewrite early island history
The finding is important because the Island of the Sun sits in Lake Titicaca and could only be reached by water for most, if not all, of that period. Researchers say the dates strongly suggest that watercraft were already in regular use at least 1,000 years earlier than earlier estimates had indicated.
The site also appears to have stayed in use for a very long time. Researchers found evidence that the area remained occupied from at least 3500 BC until about 160 BC. The excavated unit showed a deep, layered sequence of activity with no clear break in use.
New dating shows a 5,500-year-old settlement at Lake Titicaca, reshaping the timeline of early life on Bolivia’s Island of the Sun. pic.twitter.com/AfOP8In8fV
— Tom Marvolo Riddle (@tom_riddle2025) March 19, 2026
That long span offers a rare look at how life changed in the Titicaca Basin over time. Researchers say the site helps sharpen the timeline for the shift from mobile hunter-foragers to more settled communities.
At Ch’uxuqullu, they found signs of repeated and intensive use of the same place during the Late Archaic period, a pattern that points to an early move toward more stable lifeways.
Settlement at Lake Titicaca shows early stability
The new dating also refines the history of pottery on the island. Pottery first appears at the site between the 12th and 10th centuries BC, according to the study.
That places it broadly in line with developments seen in other parts of the southern Titicaca Basin, suggesting that island residents kept close ties with mainland communities.
Researchers also found obsidian and other stone materials that did not come from the island itself. Those materials add to the case for steady exchange with outside groups over a very long period. Because obsidian is absent on the island, its presence points to repeated transport from mainland sources.
Boats linked the island to mainland networks
The findings carry broader weight for how archaeologists understand the region. For years, many scholars have focused on camelid caravans as the main way goods moved across the basin. This study argues that lake travel also played a major role much earlier than previously documented.
The new dates from Ch’uxuqullu do more than identify an older settlement. They suggest that people on Lake Titicaca were using boats, maintaining exchange links and returning to favored places long before later village life took shape.
