Scientific American Frontiers on PBS

“The Secret Canyon” follows archaeologists as they explore Utah's remote Rock Creek Canyon, where the Fremont people lived between 300 and 1300, when they died out mysteriously, as did their neighbors, the pueblo-building Anasazi. The Fremonts built pit houses and oftentimes stored corn in granaries built on cliff faces. Many of their houses were perched in precarious places as well, and archaeologists want to know why.