By Caitlin Rottler The Ogallala Aquifer is a critically important aquifer in the central United States, underlying approximately 111 million acres, including 1.9 million acres of Tribal land and 2.9 million acres of federal land. The land over the aquifer is the ancestral homeland of a number of tribes, including the Sioux, Arapaho, Cheyenne, Ponca, … Continue reading The Ogallala Data Directory: A Data Resource for the Ogallala Aquifer Region