Shadows on the Trail takes place on the plains and mountains of Texas and Colorado at the end of the Ice Age, a time of escalating temperatures, melting glaciers, and large mammal extinctions. It was a time when small bands of humans fought to survive in a violent and unpredictable world. This is a tale of three prehistoric tribes whose paths collide, culminating into an emotional thriller filled with the devastating forces of nature, predatory animals, and human emotion. The seed for Shadows on the Trail sprouted on an early summer morning in 2010 on a northern Colorado ranch where the author found an Ice Age stone tool made from a red and gray striped rock from a prehistoric rock quarry from the Panhandle of Texas. How did this stone tool end up in a prehistoric campsite in northern Colorado? Who made it? What was he or she like? What happened on its journey from Texas to northern Colorado? Since it was impossible to ask the prehistoric maker of the stone tool these questions, the author wrote his version of this remarkable journey.