It would be the humane and ethical thing to do and provide water to the feral horses at Mesa Verde National Park while the main players figure out a plan. The horses are suffering a horrific and agonizing death through no fault of their own. Debating details of ethnography between horses and deer, semantics of wild vs. feral and national park use is irrelevant in the moment of such suffering. Give the horses water. It is the common sense and compassionate thing to do until a solution is agreed upon.