1. Precambrian basement geologic map of Montana, an interpretation of aeromagnetic anomalies Author/Creator: Sims, P. K. 1918-2011. (Paul Kibler) Publication/Creation: Denver, Colo. : U.S. Dept. of the Interior, U.S. Geological Survey, 2004 Resource Type: Map Edition: Version 1.0. Access & Availability: Loading