Geologic map database of the Bison Range and vicinity, northwestern Montana

This U.S. Geological Survey (USGS) data release provides a digital geospatial database for the Bison Range and surrounding area on the Flathead Reservation, northwestern Montana. Attribute tables and geospatial features (points, lines, and polygons) conform to the Geologic Map Schema (USGS NCGMP, 2020) and represent the geology for the 150 square kilometer, geologically complex map area, at a publication scale of 1:24,000. The map covers parts of Sanders and Lake Counties, Montana. All bedrock units exposed in the map area are metasedimentary rocks of the Mesoproterozoic Belt Supergroup that we mapped using a combination of field work and structural contouring. Surficial map units include Holocene alluvial and colluvial deposits, and Pleistocene glacial deposits. Previous mapping of surficial deposits (Ostenaa, 1990) was refined using high-resolution lidar from the USGS 3D Elevation Program.

References: Ostenaa, D.A., 1990, Flathead Reservation regional seismotectonic study: an evaluation for dam safety: U.S. Bureau of Reclamation Seismotectonic Report 1990-8.

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.