2013 Map of Riley Canyon

About this map

The Purgatoire River carves a deep path through the southeastern Colorado high plains, defining the topography of the Comanche National Grassland. This 2013 survey illustrates a landscape where water management is the primary driver of human activity, from the Ninemile Canal in Ninemile Valley to isolated water sources like Good Pasture Spring and the Rock Waterhole. Evidence of long-standing family ranching and settlement persists through the presence of the Martinez Cem and San Jose Cem near the river's edge. The complex network of drainages, including Riley Canyon, Jack Canyon, and Penitenta Canyon, creates a labyrinthine terrain. Scattered throughout the grassland, several landmarks such as the Girard Windmill and Little Windmill mark the essential points of access to groundwater in this arid environment.