Water has shaped the human history of Colorado for millennia, from the earliest Paleo-Indian peoples to the cliff dwellers of Mesa Verde through the irrigation projects of the twentieth century. Access to and manipulation of Colorado’s water sources has inspired migration, innovation, conflict, and preservation, while the water itself has both made and unmade lives and property. Many of the West’s great rivers flow from Colorado’s snow-capped mountains, impacting lives and landscapes far beyond the borders of state and nation. The far-reaching effects of water and agriculture in Colorado makes their interrelated history an essential part of the present and future of the American West.