1. Aeromagnetic and gravity anomaly maps and a hydrothermal veins favorability map of the Wallace 1⁰?x 2⁰?quadrangle, Montana and Idaho Yale Public content 1988. 2002-06-01T04:00:00Z. 2002-06-01T04:00:00Z. Geological Survey (U.S.). The Survey ; For sale by Branch of Distribution. English. Public. Montana and Idaho.