"Sandstone Spine: Seeking the Anasazi on the First Traverse of the Comb Ridge" is the latest book from David Roberts, one of adventure writings most accomplished authors. On 1st September, 2004, three middle-aged mates set out on one of the last geographic challenges never before attempted in North America: to hike the Comb Ridge in one continuous push. The friends - Roberts, renowned climber, Greg Child and wilderness guide, Vaughn Hadenfeldt - take on the Comb not just for the physical challenge, but to seek out seldom-visited ruins and rock art of the mysterious Anasazi culture. Each brought his own emotions on the journey: the Comb ridge would test their friendship in ways they had never before experienced.