Major revision and update of a paper on a remarkably engineeringly brilliant and energy efficiency group of thirteenth century prehistoric mountain stream fed canals in the Safford Basin area of Arizona\92s upper Gila Valley. Twenty canals of a total length of fifty kilometers are known to date. They are uniquely characterized by their being literally \94hung\94 on the edges of steep sided, gently sloping mesas formed from remnant quaternary age bajadas.
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