1. Preliminary bedrock geologic map of the International Falls 1⁰ x 2⁰?quadrangle, Minnesota, U.S.A., and Ontario, Canada [microform] Yale Public content 1987. 2002-06-01T04:00:00Z. 2002-06-01T04:00:00Z. Geological Survey (U.S.). The Survey : [Books and Open-file Reports Section]. English. Public. Minnesota and Ontario.