A team of scientists from the University of New Mexico has solved a long-standing mystery about how the ancient Puebloans of Chaco Canyon transported massive logs to build their great houses.

The team, led by archaeologist Dr. Rebecca Kintigh, conducted a series of experiments in which they hauled logs on their heads in order to simulate the conditions that the Puebloans would have faced. The experiments showed that it is possible to transport logs weighing up to 100 pounds (45 kilograms) over long distances using only human power.

The Puebloans used logs to construct their great houses, which were large, multi-story buildings made of sandstone blocks. The logs were used as beams to support the roofs of the buildings.

The team's experiments also showed that the Puebloans would have been able to transport logs over rough terrain, such as the cliffs and canyons that surround Chaco Canyon. This suggests that the Puebloans were able to access a wide range of resources when building their great houses.

The team's findings have important implications for our understanding of the Chaco Canyon civilization. They show that the Puebloans were highly skilled engineers who were able to overcome significant challenges in order to build their great houses.

The Chaco Canyon civilization flourished from about 850 to 1250 AD. It was one of the most complex and advanced civilizations in the pre-Columbian Americas. The Chacoans built some of the largest and most impressive buildings in the Americas, including the great houses of Chaco Canyon.

The Chaco Canyon civilization eventually declined, and the great houses were abandoned. The reasons for the decline are not fully known, but it is possible that a combination of factors, such as drought, famine, and warfare, played a role.