This U.S. Geological Survey (USGS) data release provides a digital geospatial database for the geologic maps of Ravalli Group and other Mesoproterozoic Belt Supergroup strata in northern Idaho and northwestern Montana (Boleneus and others, 2001). Attribute tables and geospatial features (points, lines, and polygons) conform to the Geologic Map Schema (USGS NCGMP, 2020) and represent the geologic map as published in the USGS Open-File Report 2001-438. The database represents the geology for the 2.7 million acre, geologically complex study area in eleven plates at a publication scale of 1:48,000, and two plates at a publication scale of 1:12,000. The maps cover primarily Sanders, Shoshone, Kootenai, and Lincoln Counties, but also include minor parts of Benewah and Bonner Counties. Geologic mapping was undertaken between 1979 and 1984 by ASARCO Inc. as part of their program to explore for sediment-hosted stratiform copper deposits in northern Idaho and western Montana. Geologic mapping was primarily focused on formations of the Ravalli Group, which resulted in large unmapped areas within the map boundary. In 2001 the maps were scanned, georeferenced, and published by USGS (Boleneus and others, 2001). References: Boleneus, D.E., Applegate, L.M., Joseph, N.L., and Brandt, T.R., 2001, Raster Images of Geologic Maps of Middle Proterozoic Belt strata in parts of Benewah, Bonner, Kootenai and Shoshone Counties, Idaho and Lincoln, Mineral and Sanders Counties, Montana: U.S. Geological Survey Open-File Report OF-2001-438, scales 1:48,000 and 1:12,000, https://doi.org/10.3133/ofr2001438. U.S. Geological Survey National Cooperative Geologic Mapping Program, 2020, GeMS (Geologic Map Schema) - A standard format for the digital publication of geologic maps: U.S. Geological Survey Techniques and Methods, book 11, chap. B10, 74 p., https://doi.org//10.3133/tm11B10.