In 1874, Alfred Packer, a prospector and mountain guide, appeared at the Los Pinos Indian Agency in southwestern Colorado. He declared that all his comrades had died, and near starvation had forced him to eat their flesh. On the surface, the story of Alfred Packer resembles other stories of people driven to extreme action in order to survive in the wilderness. But Packer's inability to keep his story straight and the subsequent discovery of the brutally murdered bodies of his companions tells another tale—one of murder and theft. Some began to suspect that Packer had lured the men to their deaths by his claims that he could take them across the snowy mountains. Examination of Packer's multiple versions of what happened, the recollections of those who knew Packer, court records, and other evidence support the conclusion that while cannibalism disgusted mountain miners, Packer's betrayal of these newcomers' trust infuriated them. Natural hazards, especially in the winter, played a central role in how prospectors and how those who followed them into the mountains understood their environment. Furthermore, the harsh environment shaped the interactions they had with one another. From the early days and into the early twentieth century, mountain residents depended on one another when disaster struck. This dependency, coupled with reliance on more experienced people to identify and offset risks, contributed to the creation of socio-cultural adaptations specific to the Mountain West. Packer broke the law, but he also violated codes of conduct that mountain people relied on for survival. Placing Packer within the context of mountain culture allows for a more nuanced understanding of how the environment influenced human actions in the Mountain West.