BOULDER, COLORADO—According to a statement released by the University of Colorado Boulder, the people who built wooden Great Houses in New Mexico’s Chaco Canyon between A.D. 850 and 1200 may have carried construction supplies, including more than 200,000 timbers, with tumplines—straps that loop over the top of the head to support weight with the bones of the neck and spine. “Tumplines allow one to carry heavier weights over larger distances without getting fatigued,” said researcher James Wilson. After months of training, he and Rodger Kram used this technique to carry a dried ponderosa pine log weighing more than 130 pounds over 15 miles of forest road at a pace of about three miles per hour. Inspired by Nepalese sherpas, they also carried supports called tokmas, which allowed them to rest the log without lowering it all the way to the ground when they needed to take a break. People who lived in the ancient American Southwest are thought to have woven tumplines from yucca plants to transport food and water, based upon ceramic effigies found close to Chaco Canyon. Construction supplies could have been carried in a similar way, explained team member Robert Weiner. “As these guys showed, you don’t have to be super trained to carry a log,” he said. To read about the remains of scarlet macaws and other exotic goods unearthed at Chaco Canyon, go to "Early Parrots in the Southwest."