Sampling Wood in Chuska Mountains (IMAGE) University of Arizona Caption Chris Baisan of the University of Arizona's Laboratory of Tree-Ring Research samples a dead tree in New Mexico's Chuska Mountains. The tree dates from the time that ancient Puebloans were building massive structures in Chaco Canyon, about 50 miles away. Credit Christopher H. Guiterman Usage Restrictions This photo may be used only to illustrate a story about the research described in the news release "Unexpected Wood Source for Chaco Canyon Great Houses." License Licensed content Disclaimer: AAAS and EurekAlert! are not responsible for the accuracy of news releases posted to EurekAlert! by contributing institutions or for the use of any information through the EurekAlert system.