Collection of digital structure contour maps from previously published USGS studies

Under the direction and funding of the National Cooperative Geologic Mapping Program (NCGMP) with guidance and encouragement from the United States Geological Survey (USGS), there has been a decadal strategic plan in place to call for geologic mapping across the nation. This call has been increasing the need for digital data that has not yet been made available. With such a demand, physical data is being re-released as vector-based, GIS operable data, which is viable as a corporate asset to the USGS. This collection of reports is part of the compilation and synthesis efforts hampered by the distributed nature of subsurface investigations at the USGS and a general lack of cataloging and archiving of 3-D geological models and subsurface products. Subsurface mapping activities are decentralized and the results are released on a project-by-project basis. This has led to repeats in data being created, thus wasting both time and energy of the end users. Having a clear understanding of what data is available for GIS use is paramount in the mapping groups. As digital collections of data continue, data releases like this will not be uncommon. This release features structure contour, isopach, and thickness data of stratigraphic units as well as chronostratigraphy. Units included in this release span from North Dakota to as far south as New Mexico and are as follows: San Andres Limestone, Glorieta Sandstone, Leadville Limestone, Cutler Group, Morrison Formation, Colorado Shale, Fox Hills Sandstone, Goose Egg Formation, Minnelusa Formation, Mowry Shale, Pierre Shale, Sundance Formation Unconformity, Wasatch Formation, Permian age units, Trout Creek Sandstone, Castlegate Sandstone, Exshaw or Kinderhook Black Shale, San Juan Volcanics, Lewis Shale, Almond Formation, Baxter Shale, Dakota Sandstone, Cretaceous Onlap, and Tensleep Sandstone.