These include two "dry holes" drilled by Amoco: a  well in Alger County, Michigan in 1987 and 1988, and one in Bayfield County, Wisconsin to a depth of  in 1992.
Two unsuccessful wells were drilled by Amoco: one in Alger County, Michigan from 1987 to 1988, and another in Bayfield County, Wisconsin reaching a depth of  in 1992.