This U.S. Geological Survey (USGS) data release provides an updated digital geospatial database for the geologic and structure maps of the Wallace 1 degree x 2 degrees quadrangle, Montana and Idaho (Harrison and others, 2000). Attribute tables and geospatial features (lines and polygons) conform to the Geologic Map Schema (USGS NCGMP, 2020) and represent the geologic map as published in USGS Miscellaneous Investigations Series Map I-1509-A (Harrison and others, 1986). Minor errors, such as mistakes in line decoration or differences between the digital data and the map image, are corrected in this version. The database represents the geology for the 16,754 square kilometer, geologically complex Wallace quadrangle in northern Idaho and western Montana, at a publication scale of 1:250,000. The map covers primarily Lake, Mineral, Sanders and Shoshone Counties, but also includes minor parts of Flathead, Lincoln, and Missoula Counties. These GIS data supersede those in the interpretive report (Harrison and others, 2000). References: Harrison, J.E., Griggs, A.B., Wells, J.D., Kelley, W.N., Derkey, P.D., and EROS Data Center, 2000, Geologic and structure maps of the Wallace 1 degree x 2 degrees quadrangle, Montana and Idaho: a digital database: U.S. Geological Survey Miscellaneous Investigations Series Map I-1509-A, version 1.0, 21 p., https://pubs.usgs.gov/imap/i1509a/. Harrison, J.E., Griggs, A.B., and Wells, J.D., 1986, Geologic and structure maps of the Wallace 1 degree x 2 degrees quadrangle, Montana and Idaho: U.S. Geological Survey Miscellaneous Investigations Series Map I-1509-A, 2 sheets, scale 1:250,000, https://doi.org/10.3133/i1509A. 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.