Description: The USGS National Cooperative Geologic Mapping Program (NCGMP) was directed by Congress to "bring together detailed national and continental-resolution 2D and 3D information produced throughout the Survey and by federal and state partners" (House Report 116-100), to create a new geologic map of the United States. To fulfill this goal, the NCGMP created a map synthesis engine (Johnstone and others, 2025) based on the Geologic Map Schema (GeMS) standard and used it to bring together and (to some extent) to harmonize source geologic maps originally published by the USGS and by State Geological Surveys. Currently, this map covers the conterminous U.S.; however, work is underway to expand the coverage.The Earth’s Surface geology layer depicts geologic units exposed at the Earth’s surface in the conterminous United States, ranging in age from Quaternary glacial deposits and alluvium to Precambrian crystalline bedrock. In the U.S. West and Southeast, the map is a composite of 29 state geologic maps depicting geology at the Earth’s surface. In the glaciated region of the Midwest and Northeast, the map is a composite of 21 state geologic maps depicting pre-Quaternary rocks ("bedrock"), 8 state geologic maps depicting Quaternary deposits, and 18 USGS Quaternary Atlas Series maps depicting Quaternary deposits. The Quaternary Atlas maps were used where modern state geologic maps were not available.This layer is one of four created for the new national geologic map. The other layers available are: Quaternary (geologic units of Quaternary age, exposed at the Earth’s surface) Pre-Quaternary (geologic units older than Quaternary, including many "bedrock" geologic maps) Precambrian (emphasizes Precambrian units at Earth's surface and those depicted in "basement" maps).Each layer is published by the USGS as GeMS-compliant Esri geodatabases. Those geodatabases are products of the overall geospatial database, which is published as a geopackage. These products and static images of the layers are available from the National Geologic Map Database, at https://ngmdb.usgs.gov/Prodesc/proddesc_118545.htm. For a more performant viewing and data exploration experience for the four layers, please visit the web application at ngmdb.usgs.gov/nationalgeology.