2020 Map of Guano Reservoir

About this map

Catlow Valley dominates this high-desert landscape in southeastern Oregon, where the drainage patterns of Guano Slough dictate the geography. The seasonal waters of the slough lead into the Guano Reservoir, a critical water source in an arid basin. The terrain is defined by dramatic volcanic features and depressions, including the prominent Cox Butte in the northwest and the deep cut of Black Canyon. This 2020 survey provides a modern view of a remote region where the Lake Co Harney Co boundary line traverses the sagebrush-covered plains. Human impact remains sparse, represented largely by the path of Red Hills Rd, which provides access across these expansive ranch lands and public basins.