The data release for the geologic and structure map of the Choteau 1 x 2 degree quadrangle, western Montana, is a Geologic Map Schema (GeMS)-compliant version that updates the GIS files for the geologic map published in U.S. Geological Survey (USGS) Miscellaneous Investigations Series Map I-1300 (Mudge and others, 2001). The updated digital data present the attribute tables and geospatial features (lines and polygons) in the format that meets GeMS requirements. This data release presents geospatial data for the geologic map that is published as two plates. 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 4.2 million acre, geologically complex Choteau 1 x 2 degree quadrangle, at a publication scale of 1:250,000. The map covers primarily Lewis and Clark, Teton, Powell, Missoula, Lake, and Flathead Counties, but also includes minor parts of Cascade County. These GIS data supersede those in the report: Mudge, M.R., Earhart, R.L., Whipple, J.W., Harrison, J.E., Munts, S.R., and Silkwood, J.T., 2001, Geologic and structure map of the Choteau 1 x 2 degree quadrangle, western Montana: a digital database: U.S. Geological Survey Miscellaneous Investigations Series Map I-1300, version 1.0, 38 p., scale 1:250,000, https://pubs.er.usgs.gov/publication/i1300.