Winding their way across the Great Plains like so many ribbons, rivers and streams were vital to survival for all lifeforms that inhabited the parched expanse. For humans, watercourses also served as directional aids, tracks for travel corridors, and convenient boundaries. The Cache la Poudre was such a river. Its verdant valley was referred to as the jáaianahâw by the Arapaho people and first appear on a map of the region as a result of...