You searched for: Institution University of Michigan. Libraries Remove constraint Institution: University of Michigan. Libraries Place Sierra Madre del Sur, along the Milpillas-Atoyac road via Puerto del Gallo, about 65 miles northeast of Atoyac and 10.8 miles northeast of Puerto del Gallo Remove constraint Place: Sierra Madre del Sur, along the Milpillas-Atoyac road via Puerto del Gallo, about 65 miles northeast of Atoyac and 10.8 miles northeast of Puerto del Gallo