Smout, Brooklyn 20250429 1 vector digital data Lakewood, CO U.S. Geological Survey https://doi.org/10.5066/P14KMRL9 This GIS dataset presents contours and maps from previously published interpretations of hydrogeologic units of the northern Great Plains by Downey (1986). The original source publication was completed as a component of the United States Geological Survey’s (USGS) Regional Aquifer System Analysis (RASA) professional paper series. Isopach contour maps in this study delineate the upper surfaces of the Bakken Formation, Big Snowy Group, Deadwood Formation, Interlake Formation, Madison Group, Red River Formation as well as the depositional boundary extents of the Charles Salt, Prairie Salt, Opeche Salt, Pine Salt, Middle Madison Salt(s), and Dunham Salt. Geologic Period isopach contours included are Cambrian, Ordovician, Devonian, Pennsylvanian, Permian, Triassic, Jurassic, and Lower Cretaceous. The Northern Great Plains regional bedrock aquifer system is broadly composed of five major bedrock aquifer systems described in the source report, extending beneath large portions of Montana, North Dakota, South Dakota, Wyoming, and into Nebraska. This digital dataset was created as part of the U.S. Geological Survey’s effort to inventory, catalog, and release 2D and 3D geologic information across the conterminous US at detailed, national, and continental scales. The intended uses of this dataset include, but are not limited to natural resource modeling, mapping, and visualization. Structure contour lines are distributed as separate feature classes within a geographic information system geodatabase and are also saved as shapefiles. Nonspatial tables define the data sources used, the terms used in the dataset, and the geologic units. A tabular data dictionary describes the entity and attribute information for all attributes of the geospatial data and the accompanying nonspatial tables. This geodatabase is not compliant with the GeMS data schema, but attempts to follow the schema and structure of GeMS [https://ngmdb.usgs.gov/Info/standards/GeMS/]. Not all components of the GeMS data model are utilized in this database. Components used in construction of this database are explained in the Entity and Attribute section. 1970 1995 publication date Complete None planned Northern Great Plains -111.0059 -96.1523 48.9802 42.2285 ISO 19115 Topic Category elevation geoscientificInformation location structure Geology Bakken Formation Big Snowy Group Deadwood Formation Devonian Cretaceous Interlake Formation Jurassic aquifer Madison Group Lower Cretaceous Ordovician Pennsylvanian Permian Red River Formation Triassic Middle Madison Limestone Charles Salt Prairie Salt Opeche Salt Pine Salt Dunham Salt None vector structure contour isopach contour thickness contour estimated thickness elevation Federal Geographic Data Committee National Cooperative Geologic Map Program GeMS Geologic Mapping Schema USGS Metadata Identifier USGS:66bcff2bd34e03388281ba6a Location Northern Great Plains North Dakota South Dakota Wyoming Montana Nebraska None. Please see 'Distribution Info' for details. Unless otherwise stated, all data, metadata and related materials are considered to satisfy the quality standards relative to the purpose for which the data were collected. Although these data and associated metadata have been reviewed for accuracy and completeness and approved for release by the U.S. Geological Survey (USGS), no warranty expressed or implied is made regarding the display or utility of the data on any other system or for general or scientific purposes, nor shall the act of distribution constitute any such warranty. Brooklyn Smout USGS - ROCKY MOUNTAIN REGION Geologist mailing and physical

Denver Federal Center,DFC Bldg 25

Lakewood CO 80225 303-236-1231 bsmout@usgs.gov This data release study was funded by the USGS National Cooperative Geologic Mapping Program. Dataset improvements done by thoughtful technical reviews by Leland Spangler and Paco van Sistine, March 2025. ArcGIS Pro v 3.3.0 J. S. Downey 1986 publication n/a US Geological Survey https://doi.org/10.3133/pp1402E Leland R Spangler 2024 dataset https://www.sciencebase.gov U.S. Geological Survey https://doi.org/10.5066/p9lk4qhj No formal attribute accuracy tests were conducted. Verification was done by interactive on-screen review. No formal attribute accuracy tests were conducted. Verification was done by interactive on-screen review. Dataset is considered complete for the information presented. A formal accuracy assessment of the horizontal positional information in the dataset has not been conducted. A formal accuracy assessment of the vertical positional information in the dataset has not been conducted. J. S. Downey 1986 publication n/a US Geological Survey https://doi.org/10.3133/pp1402E Digital and/or Hardcopy 1986 publication date Geohydrology of bedrock aquifers in the Northern Great Plains in parts of Montana, North Dakota, South Dakota, and Wyoming Legacy map Obtaining reference material: Author obtained reference material from Downey (1986). Original plate(s) were downloaded, georeferenced, and projected into a GIS (ArcGIS Pro). Downey, J.S., 1986, Geohydrology of bedrock aquifers in the Northern Great Plains in parts of Montana, North Dakota, South Dakota, and Wyoming: U.S. Geological Survey, Professional Paper 1402-E, doi: 10.3133/pp1402E. Spangler, L.R., 2024, Digital data for a 3D Geological Model of western South Dakota, USA: U.S. Geological Survey, data release, https://doi.org/10.5066/P9LK4QHJ. 2024 Author creates a project workspace in ArcGIS Pro: 1- The Author created a geodatabase from the FGDC Digital Cartographic Standard for Geologic Map Symbolization GeMS Template to properly organize data. 2- Map and feature classes were projected in NAD 1983 Contiguous USA Albers (WIKID 5070). 3- Inserted map TIFF to project workspace and reprojected data to NAD 1983 Contiguous USA Albers WIKID 5070 projection. 2024 Digitizing Process: The author digitized this legacy map to faithfully reproduce a digital facsimile of the original publication. The author recognizes the importance of digitizing the following elements: structure contours, isopach contours, unit extent boundaries, and faults. Digitized features were followed faithfully to ensure the most accurate representation of the legacy map, however actual map illustrations and virtual digitized lines may differ from ground features by up to 500m. Isopach lines and boundary extent lines were chosen to digitize as features were found valuable. 'Boundary of Salt Extent' lines digitized for six salt deposits. 2024 Validation: This 3D subsurface dataset does not conform to the traditional intended use of the GEMS data format for surface geologic maps. Therefore, it is incumbent upon the author to format data in the spirit of the GEMS schema, despite non-compliance with the GEMS Level 3 standard including topological checks. Within the “NorthGreatPlains_USGS_Albers” geodatabase, it is clear that the author took considerable care to roughly follow the spirit of the GEMS schema, notably with respect to model input data which has been generally formatted in the style of traditional GEMS feature classes “geologic lines” and “isovaluelines”. As of this review, this work is not GEMS compliant, however it does not need to be. In efforts to semi-comply with Geologic Mapping Schema (GeMS) compliance, a validation of the maps attributes and features was performed. Validating these features is to ensure the map data is adequately represented on a map but also to ensure that there are not any errors. Errors such as mis-matched attributes and that standalone / nonspatial tables additionally comply. To fix errors in validation, using available tools for aid is efficient and effective. The author began this validation by downloading the GeMS Validation toolbox and add it to the active map. This tool script ran with the active map geodatabase as the input and created a new 'Validation' folder in the Map Project folder once the script is complete. Once validation was completed, the two areas to focus attention to fixing were the attribute tables from the topological feature classes and the nonspatial attribute table errors. These errors were reported in script in .html format. 2024 Review: At the conclusion of the authors validation compliance efforts, a peer reviewer was assigned to complete any additional data, metadata, and technical reviews. This review was conducted by Donald Sweetkind & Leland Spangler. Reviewed documents were returned to the author for reconciliation. All additional reconciled comments from the reviewer were made to a separate document including comments made to map features, templates, nonspatial tables, standalone tables, and FGDC standards. The final review was conducted by the metadata reviewer Paco VanSistine, who screened for any additional errors. 2025 Metadata: A metadata file was written to provide background information, credit, and other attribution relevant to this dataset such as spatial extent, purpose of the map, entity and attributes data dictionary, dataset types, any identifying features, distribution methods, and credits. 2025 Smout, B., 2025, Digital data of isopach features and salt extent boundaries from previously published Regional Aquifer System Analysis (RASA) studies on the Northern Great Plains of Wyoming, North Dakota, South Dakota, Montana, and Nebraska: U.S. Geological Survey, https://doi.org/10.5066/P14KMRL9. Vector Node, network NorthernGreatPlains_RASA.gdb ***All features classes in projected coordinates of NAD_1983_Contiguous_USA_Albers, WKID: 5070 Authority: EPSG*** Table Field Definition Units DataSources.csv Source Short, terse, easily understood ASCII-character identifier for a data source NA DataSources.csv FullCitation Complete citation of publication NA DataSources.csv URL URL link to data (at time of publication), if available NA DataSources.csv Notes Free text for additional information specific to this entry. NA DataSources.csv DataSource_ID Foreign key to DataSources table, to track provenance of each data element. Values must be unique in database. Null values not permitted NA Glossary.csv Term Geologic concept, feature, phenomenon, or other terminology being defined. Values must be unique within database. Null values not permitted NA Glossary.csv Definition Definition of value in Term NA Glossary.csv DefinitionSource_ID Identifies source of definition. Foreign key to DataSources table NA Glossary.csv Notes Optional field. Free text for additional information specific to this feature. Free text for additional information specific to this line feature. Null values permitted NA Glossary.csv Glossary_ID Prefix "GLO". Values must be unique in database. Null values not permitted NA DescriptionOfMapUnits.csv MapUnit Short descriptor of unit or surface being mapped. NA DescriptionOfMapUnits.csv Name Full name of formal or informal map unit. NA DescriptionOfMapUnits.csv FullName Full name of formal or informal map unit. NA DescriptionOfMapUnits.csv Age Geologic age of map unit; Period or Epoch of unit consistent with GSA time scale NA DescriptionOfMapUnits.csv Description Full text description of map unit NA DescriptionOfMapUnits.csv ParagraphStyle Name of user-defined paragraph style that indicates hierarchy of map units and headings within DMU. Values must be defined in Glossary table; definition typically includes formatting specifications NA DescriptionOfMapUnits.csv HierarchyKey Text string that indicates place of map unit or heading within DMU hierarchy. Text string has form of “n-n-n”, “nn-nn”, “nn-nn-nn”, “nnn-nnn”, or similar; each dash-delimited fragment of string (1) is numeric, (2) has same length as others in string and in DescriptionOfMapUnits table, and (3) is left-padded with zeroes if values exceed one digit. NA DescriptionOfMapUnits.csv Symbol Abbreviated version of Geologic Unit, null values permitted. NA DescriptionOfMapUnits.csv Label Describes text label for map-unit polygons. Field from which map-unit label is generated NA DescriptionOfMapUnits.csv DescriptionSourceID Identifies source of Description. Foreign key to DataSources table NA DescriptionOfMapUnits.csv GeoMaterial Term categorizing the dominant lithology in the map feature. Term derived from NGMDB standard term list in Appendix 1 of the GeMS data model https://ngmdb.usgs.gov/Info/standards/GeMS/) NA DescriptionOfMapUnits.csv AreaFillRGB Map Unit Polygon color fill reported in RGB values from the FGDC standard. Null values permitted. NA DescriptionOfMapUnits.csv AreaFillPatternDescription Map Unit Polygon color fill and descriptive representation reported in RGB values from the FGDC standard. Null values permitted. NA DescriptionOfMapUnits.csv GeoMaterialConfidence Qualitative term describing appropriateness of the GeoMaterial term used (low, medium, high). NA DescriptionOfMapUnits.csv Notes Free text for additional information specific to this entry. NA DescriptionOfMapUnits.csv DescriptionOfMapUnits_ID Prefix "DMU". Values must be unique in database. Null values not permitted. NA GeoMaterialDict.csv HierarchyKey Delimited text string used to indicate order and hierarchical relations between parent and child records. NA GeoMaterialDict.csv GeoMaterial Categorization of map unit based on lithologic and genetic character, term selected from NGMDB standard term list defined in Appendix A of GeMS documentation, available at http://ngmdb.usgs.gov/Info/standards/GeMS. NA GeoMaterialDict.csv IndentedName Name with addition of leading spaces to help show rank within a hierarchical list. NA GeoMaterialDict.csv Definition Plain-language definition. NA GeologicLines_RASALimits Type Specifies kind of line feature represented by this database row. Values must be defined in Glossary table. Null values not permitted feet, meters GeologicLines_RASALimits MapUnit Short, easily understood ASCII-character identifier for the map unit represented by this polygon. Foreign key to DescriptionOfMapUnits table. Use of special characters is discouraged feet, meters GeologicLines_RASALimits IsConcealed Indicates whether this contact or fault is concealed by an overlying map unit. Values = “N” or “Y”. Null values not permitted feet, meters GeologicLines_RASALimits LocationConfidenceMeters Half-width (in meters) of positional-uncertainty envelope around this line feature. Data type = float. Null values not permitted; recommend setting value = ?9 if value is not known feet, meters GeologicLines_RASALimits ExistenceConfidence Indicates how confidently existence of this line feature has been determined. Typical values are “certain”, “questionable”, “unspecified”. Values must be defined in Glossary table. Null values not permitted feet, meters GeologicLines_RASALimits IdentityConfidence Indicates how confidently this line feature has been identified as a particular type. Typical values are “certain”, “questionable”, “unspecified”. Values must be defined in Glossary table. Null values not permitted feet, meters GeologicLines_RASALimits Symbol References a line symbol in USGS FGDC Digital Cartographic Standard for Geologic Map Symbolization (https://pubs.usgs.gov/tm/2006/11A02/) feet, meters GeologicLines_RASALimits Label Describes text label for this line feature. Can be used to store fault name or other easily understood name for line feature. Allows for special fonts to show geologic age symbols. Null values are typical feet, meters GeologicLines_RASALimits DataSourceID Identifies source of each data element. Foreign key to DataSources table. Null values not permitted feet, meters GeologicLines_RASALimits Notes Optional field. Free text for additional information specific to this feature. Free text for additional information specific to this line feature. Null values permitted feet, meters GeologicLines_RASALimits GeologicLines_ID Primary key. Prefix "GL". Values must be unique in database. Null values not permitted. feet, meters IsoValueLines_Bakken Type Specifies kind of line feature represented by this database row. Values must be defined in Glossary table. Null values not permitted feet, meters IsoValueLines_Bakken MapUnit Short, easily understood ASCII-character identifier for the map unit represented by this polygon. Foreign key to DescriptionOfMapUnits table. Use of special characters is discouraged feet, meters IsoValueLines_Bakken Value_ft Specifies measured value in feet that pertains to this line feature. Date type = float. Null values not permitted feet, meters IsoValueLines_Bakken Value_m Specifies measured value in meters that pertains to this line feature, value calculated and rounded to the nearest whole number from original value in feet. Date type = float. Null values not permitted feet, meters IsoValueLines_Bakken ValueConfidence Half-width (in meters) of positional-uncertainty envelope around this line feature. Data type = float. Null values not permitted; recommend setting value = ?9 if value is not known feet, meters IsoValueLines_Bakken Symbol References a line symbol in USGS FGDC Digital Cartographic Standard for Geologic Map Symbolization (https://pubs.usgs.gov/tm/2006/11A02/) feet, meters IsoValueLines_Bakken Label Describes text label for this line feature. Can be used to store fault name or other easily understood name for line feature. Allows for special fonts to show geologic age symbols. Null values are typical feet, meters IsoValueLines_Bakken DataSourceID Identifies source of each data element. Foreign key to DataSources table. Null values not permitted feet, meters IsoValueLines_Bakken Notes Optional field. Free text for additional information specific to this feature. Free text for additional information specific to this line feature. Null values permitted feet, meters IsoValueLines_Bakken IsoValueLines_Bakken_ID Primary key. Prefix "IVL". Values must be unique in database. Null values not permitted. feet, meters IsoValueLines_BigSnowy Type Specifies kind of line feature represented by this database row. Values must be defined in Glossary table. Null values not permitted feet, meters IsoValueLines_BigSnowy MapUnit Short, easily understood ASCII-character identifier for the map unit represented by this polygon. Foreign key to DescriptionOfMapUnits table. Use of special characters is discouraged feet, meters IsoValueLines_BigSnowy Value_ft Specifies measured value in feet that pertains to this line feature. Date type = float. Null values not permitted feet, meters IsoValueLines_BigSnowy Value_m Specifies measured value in meters that pertains to this line feature, value calculated and rounded to the nearest whole number from original value in feet. Date type = float. Null values not permitted feet, meters IsoValueLines_BigSnowy ValueConfidence Half-width (in meters) of positional-uncertainty envelope around this line feature. Data type = float. Null values not permitted; recommend setting value = ?9 if value is not known feet, meters IsoValueLines_BigSnowy Symbol References a line symbol in USGS FGDC Digital Cartographic Standard for Geologic Map Symbolization (https://pubs.usgs.gov/tm/2006/11A02/) feet, meters IsoValueLines_BigSnowy Label Describes text label for this line feature. Can be used to store fault name or other easily understood name for line feature. Allows for special fonts to show geologic age symbols. Null values are typical feet, meters IsoValueLines_BigSnowy DataSourceID Identifies source of each data element. Foreign key to DataSources table. Null values not permitted feet, meters IsoValueLines_BigSnowy Notes Optional field. Free text for additional information specific to this feature. Free text for additional information specific to this line feature. Null values permitted feet, meters IsoValueLines_BigSnowy IsoValueLines_BigSnowy_ID Primary key. Prefix "IVL". Values must be unique in database. Null values not permitted. feet, meters IsoValueLines_CambOrdovician Type Specifies kind of line feature represented by this database row. Values must be defined in Glossary table. Null values not permitted feet, meters IsoValueLines_CambOrdovician MapUnit Short, easily understood ASCII-character identifier for the map unit represented by this polygon. Foreign key to DescriptionOfMapUnits table. Use of special characters is discouraged feet, meters IsoValueLines_CambOrdovician Value_ft Specifies measured value in feet that pertains to this line feature. Date type = float. Null values not permitted feet, meters IsoValueLines_CambOrdovician Value_m Specifies measured value in meters that pertains to this line feature, value calculated and rounded to the nearest whole number from original value in feet. Date type = float. Null values not permitted feet, meters IsoValueLines_CambOrdovician ValueConfidence Half-width (in meters) of positional-uncertainty envelope around this line feature. Data type = float. Null values not permitted; recommend setting value = ?9 if value is not known feet, meters IsoValueLines_CambOrdovician Symbol References a line symbol in USGS FGDC Digital Cartographic Standard for Geologic Map Symbolization (https://pubs.usgs.gov/tm/2006/11A02/) feet, meters IsoValueLines_CambOrdovician Label Describes text label for this line feature. Can be used to store fault name or other easily understood name for line feature. Allows for special fonts to show geologic age symbols. Null values are typical feet, meters IsoValueLines_CambOrdovician DataSourceID Identifies source of each data element. Foreign key to DataSources table. Null values not permitted feet, meters IsoValueLines_CambOrdovician Notes Optional field. Free text for additional information specific to this feature. Free text for additional information specific to this line feature. Null values permitted feet, meters IsoValueLines_CambOrdovician IsoValueLines_CambOrdovician_ID Primary key. Prefix "IVL". Values must be unique in database. Null values not permitted. feet, meters IsoValueLines_Cretaceous Type Specifies kind of line feature represented by this database row. Values must be defined in Glossary table. Null values not permitted feet, meters IsoValueLines_Cretaceous MapUnit Short, easily understood ASCII-character identifier for the map unit represented by this polygon. Foreign key to DescriptionOfMapUnits table. Use of special characters is discouraged feet, meters IsoValueLines_Cretaceous Value_ft Specifies measured value in feet that pertains to this line feature. Date type = float. Null values not permitted feet, meters IsoValueLines_Cretaceous Value_m Specifies measured value in meters that pertains to this line feature, value calculated and rounded to the nearest whole number from original value in feet. Date type = float. Null values not permitted feet, meters IsoValueLines_Cretaceous ValueConfidence Half-width (in meters) of positional-uncertainty envelope around this line feature. Data type = float. Null values not permitted; recommend setting value = ?9 if value is not known feet, meters IsoValueLines_Cretaceous Symbol References a line symbol in USGS FGDC Digital Cartographic Standard for Geologic Map Symbolization (https://pubs.usgs.gov/tm/2006/11A02/) feet, meters IsoValueLines_Cretaceous Label Describes text label for this line feature. Can be used to store fault name or other easily understood name for line feature. Allows for special fonts to show geologic age symbols. Null values are typical feet, meters IsoValueLines_Cretaceous DataSourceID Identifies source of each data element. Foreign key to DataSources table. Null values not permitted feet, meters IsoValueLines_Cretaceous Notes Optional field. Free text for additional information specific to this feature. Free text for additional information specific to this line feature. Null values permitted feet, meters IsoValueLines_Cretaceous IsoValueLines_Cretaceous_ID Primary key. Prefix "IVL". Values must be unique in database. Null values not permitted. feet, meters IsoValueLines_Deadwood Type Specifies kind of line feature represented by this database row. Values must be defined in Glossary table. Null values not permitted feet, meters IsoValueLines_Deadwood MapUnit Short, easily understood ASCII-character identifier for the map unit represented by this polygon. Foreign key to DescriptionOfMapUnits table. Use of special characters is discouraged feet, meters IsoValueLines_Deadwood Value_ft Specifies measured value in feet that pertains to this line feature. Date type = float. Null values not permitted feet, meters IsoValueLines_Deadwood Value_m Specifies measured value in meters that pertains to this line feature, value calculated and rounded to the nearest whole number from original value in feet. Date type = float. Null values not permitted feet, meters IsoValueLines_Deadwood ValueConfidence Half-width (in meters) of positional-uncertainty envelope around this line feature. Data type = float. Null values not permitted; recommend setting value = ?9 if value is not known feet, meters IsoValueLines_Deadwood Symbol References a line symbol in USGS FGDC Digital Cartographic Standard for Geologic Map Symbolization (https://pubs.usgs.gov/tm/2006/11A02/) feet, meters IsoValueLines_Deadwood Label Describes text label for this line feature. Can be used to store fault name or other easily understood name for line feature. Allows for special fonts to show geologic age symbols. Null values are typical feet, meters IsoValueLines_Deadwood DataSourceID Identifies source of each data element. Foreign key to DataSources table. Null values not permitted feet, meters IsoValueLines_Deadwood Notes Optional field. Free text for additional information specific to this feature. Free text for additional information specific to this line feature. Null values permitted feet, meters IsoValueLines_Deadwood IsoValueLines_Deadwood_ID Primary key. Prefix "IVL". Values must be unique in database. Null values not permitted. feet, meters IsoValueLines_Devonian Type Specifies kind of line feature represented by this database row. Values must be defined in Glossary table. Null values not permitted feet, meters IsoValueLines_Devonian MapUnit Short, easily understood ASCII-character identifier for the map unit represented by this polygon. Foreign key to DescriptionOfMapUnits table. Use of special characters is discouraged feet, meters IsoValueLines_Devonian Value_ft Specifies measured value in feet that pertains to this line feature. Date type = float. Null values not permitted feet, meters IsoValueLines_Devonian Value_m Specifies measured value in meters that pertains to this line feature, value calculated and rounded to the nearest whole number from original value in feet. Date type = float. Null values not permitted feet, meters IsoValueLines_Devonian ValueConfidence Half-width (in meters) of positional-uncertainty envelope around this line feature. Data type = float. Null values not permitted; recommend setting value = ?9 if value is not known feet, meters IsoValueLines_Devonian Symbol References a line symbol in USGS FGDC Digital Cartographic Standard for Geologic Map Symbolization (https://pubs.usgs.gov/tm/2006/11A02/) feet, meters IsoValueLines_Devonian Label Describes text label for this line feature. Can be used to store fault name or other easily understood name for line feature. Allows for special fonts to show geologic age symbols. Null values are typical feet, meters IsoValueLines_Devonian DataSourceID Identifies source of each data element. Foreign key to DataSources table. Null values not permitted feet, meters IsoValueLines_Devonian Notes Optional field. Free text for additional information specific to this feature. Free text for additional information specific to this line feature. Null values permitted feet, meters IsoValueLines_Devonian IsoValueLines_Devonian_ID Primary key. Prefix "IVL". Values must be unique in database. Null values not permitted. feet, meters IsoValueLines_Interlake Type Specifies kind of line feature represented by this database row. Values must be defined in Glossary table. Null values not permitted feet, meters IsoValueLines_Interlake MapUnit Short, easily understood ASCII-character identifier for the map unit represented by this polygon. Foreign key to DescriptionOfMapUnits table. Use of special characters is discouraged feet, meters IsoValueLines_Interlake Value_ft Specifies measured value in feet that pertains to this line feature. Date type = float. Null values not permitted feet, meters IsoValueLines_Interlake Value_m Specifies measured value in meters that pertains to this line feature, value calculated and rounded to the nearest whole number from original value in feet. Date type = float. Null values not permitted feet, meters IsoValueLines_Interlake ValueConfidence Half-width (in meters) of positional-uncertainty envelope around this line feature. Data type = float. Null values not permitted; recommend setting value = ?9 if value is not known feet, meters IsoValueLines_Interlake Symbol References a line symbol in USGS FGDC Digital Cartographic Standard for Geologic Map Symbolization (https://pubs.usgs.gov/tm/2006/11A02/) feet, meters IsoValueLines_Interlake Label Describes text label for this line feature. Can be used to store fault name or other easily understood name for line feature. Allows for special fonts to show geologic age symbols. Null values are typical feet, meters IsoValueLines_Interlake DataSourceID Identifies source of each data element. Foreign key to DataSources table. Null values not permitted feet, meters IsoValueLines_Interlake Notes Optional field. Free text for additional information specific to this feature. Free text for additional information specific to this line feature. Null values permitted feet, meters IsoValueLines_Interlake IsoValueLines_Interlake_ID Primary key. Prefix "IVL". Values must be unique in database. Null values not permitted. feet, meters IsoValueLines_Jurassic Type Specifies kind of line feature represented by this database row. Values must be defined in Glossary table. Null values not permitted feet, meters IsoValueLines_Jurassic MapUnit Short, easily understood ASCII-character identifier for the map unit represented by this polygon. Foreign key to DescriptionOfMapUnits table. Use of special characters is discouraged feet, meters IsoValueLines_Jurassic Value_ft Specifies measured value in feet that pertains to this line feature. Date type = float. Null values not permitted feet, meters IsoValueLines_Jurassic Value_m Specifies measured value in meters that pertains to this line feature, value calculated and rounded to the nearest whole number from original value in feet. Date type = float. Null values not permitted feet, meters IsoValueLines_Jurassic ValueConfidence Half-width (in meters) of positional-uncertainty envelope around this line feature. Data type = float. Null values not permitted; recommend setting value = ?9 if value is not known feet, meters IsoValueLines_Jurassic Symbol References a line symbol in USGS FGDC Digital Cartographic Standard for Geologic Map Symbolization (https://pubs.usgs.gov/tm/2006/11A02/) feet, meters IsoValueLines_Jurassic Label Describes text label for this line feature. Can be used to store fault name or other easily understood name for line feature. Allows for special fonts to show geologic age symbols. Null values are typical feet, meters IsoValueLines_Jurassic DataSourceID Identifies source of each data element. Foreign key to DataSources table. Null values not permitted feet, meters IsoValueLines_Jurassic Notes Optional field. Free text for additional information specific to this feature. Free text for additional information specific to this line feature. Null values permitted feet, meters IsoValueLines_Jurassic IsoValueLines_Jurassic_ID Primary key. Prefix "IVL". Values must be unique in database. Null values not permitted. feet, meters IsoValueLines_LowerK Type Specifies kind of line feature represented by this database row. Values must be defined in Glossary table. Null values not permitted feet, meters IsoValueLines_LowerK MapUnit Short, easily understood ASCII-character identifier for the map unit represented by this polygon. Foreign key to DescriptionOfMapUnits table. Use of special characters is discouraged feet, meters IsoValueLines_LowerK Value_ft Specifies measured value in feet that pertains to this line feature. Date type = float. Null values not permitted feet, meters IsoValueLines_LowerK Value_m Specifies measured value in meters that pertains to this line feature, value calculated and rounded to the nearest whole number from original value in feet. Date type = float. Null values not permitted feet, meters IsoValueLines_LowerK ValueConfidence Half-width (in meters) of positional-uncertainty envelope around this line feature. Data type = float. Null values not permitted; recommend setting value = ?9 if value is not known feet, meters IsoValueLines_LowerK Symbol References a line symbol in USGS FGDC Digital Cartographic Standard for Geologic Map Symbolization (https://pubs.usgs.gov/tm/2006/11A02/) feet, meters IsoValueLines_LowerK Label Describes text label for this line feature. Can be used to store fault name or other easily understood name for line feature. Allows for special fonts to show geologic age symbols. Null values are typical feet, meters IsoValueLines_LowerK DataSourceID Identifies source of each data element. Foreign key to DataSources table. Null values not permitted feet, meters IsoValueLines_LowerK Notes Optional field. Free text for additional information specific to this feature. Free text for additional information specific to this line feature. Null values permitted feet, meters IsoValueLines_LowerK IsoValueLines_LowerK_ID Primary key. Prefix "IVL". Values must be unique in database. Null values not permitted. feet, meters IsoValueLines_Madison Type Specifies kind of line feature represented by this database row. Values must be defined in Glossary table. Null values not permitted feet, meters IsoValueLines_Madison MapUnit Short, easily understood ASCII-character identifier for the map unit represented by this polygon. Foreign key to DescriptionOfMapUnits table. Use of special characters is discouraged feet, meters IsoValueLines_Madison Value_ft Specifies measured value in feet that pertains to this line feature. Date type = float. Null values not permitted feet, meters IsoValueLines_Madison Value_m Specifies measured value in meters that pertains to this line feature, value calculated and rounded to the nearest whole number from original value in feet. Date type = float. Null values not permitted feet, meters IsoValueLines_Madison ValueConfidence Half-width (in meters) of positional-uncertainty envelope around this line feature. Data type = float. Null values not permitted; recommend setting value = ?9 if value is not known feet, meters IsoValueLines_Madison Symbol References a line symbol in USGS FGDC Digital Cartographic Standard for Geologic Map Symbolization (https://pubs.usgs.gov/tm/2006/11A02/) feet, meters IsoValueLines_Madison Label Describes text label for this line feature. Can be used to store fault name or other easily understood name for line feature. Allows for special fonts to show geologic age symbols. Null values are typical feet, meters IsoValueLines_Madison DataSourceID Identifies source of each data element. Foreign key to DataSources table. Null values not permitted feet, meters IsoValueLines_Madison Notes Optional field. Free text for additional information specific to this feature. Free text for additional information specific to this line feature. Null values permitted feet, meters IsoValueLines_Madison IsoValueLines_Madison_ID Primary key. Prefix "IVL". Values must be unique in database. Null values not permitted. feet, meters IsoValueLines_Ordovician Type Specifies kind of line feature represented by this database row. Values must be defined in Glossary table. Null values not permitted feet, meters IsoValueLines_Ordovician MapUnit Short, easily understood ASCII-character identifier for the map unit represented by this polygon. Foreign key to DescriptionOfMapUnits table. Use of special characters is discouraged feet, meters IsoValueLines_Ordovician Value_ft Specifies measured value in feet that pertains to this line feature. Date type = float. Null values not permitted feet, meters IsoValueLines_Ordovician Value_m Specifies measured value in meters that pertains to this line feature, value calculated and rounded to the nearest whole number from original value in feet. Date type = float. Null values not permitted feet, meters IsoValueLines_Ordovician ValueConfidence Half-width (in meters) of positional-uncertainty envelope around this line feature. Data type = float. Null values not permitted; recommend setting value = ?9 if value is not known feet, meters IsoValueLines_Ordovician Symbol References a line symbol in USGS FGDC Digital Cartographic Standard for Geologic Map Symbolization (https://pubs.usgs.gov/tm/2006/11A02/) feet, meters IsoValueLines_Ordovician Label Describes text label for this line feature. Can be used to store fault name or other easily understood name for line feature. Allows for special fonts to show geologic age symbols. Null values are typical feet, meters IsoValueLines_Ordovician DataSourceID Identifies source of each data element. Foreign key to DataSources table. Null values not permitted feet, meters IsoValueLines_Ordovician Notes Optional field. Free text for additional information specific to this feature. Free text for additional information specific to this line feature. Null values permitted feet, meters IsoValueLines_Ordovician IsoValueLines_Ordovician_ID Primary key. Prefix "IVL". Values must be unique in database. Null values not permitted. feet, meters IsoValueLines_PennPerm Type Specifies kind of line feature represented by this database row. Values must be defined in Glossary table. Null values not permitted feet, meters IsoValueLines_PennPerm MapUnit Short, easily understood ASCII-character identifier for the map unit represented by this polygon. Foreign key to DescriptionOfMapUnits table. Use of special characters is discouraged feet, meters IsoValueLines_PennPerm Value_ft Specifies measured value in feet that pertains to this line feature. Date type = float. Null values not permitted feet, meters IsoValueLines_PennPerm Value_m Specifies measured value in meters that pertains to this line feature, value calculated and rounded to the nearest whole number from original value in feet. Date type = float. Null values not permitted feet, meters IsoValueLines_PennPerm ValueConfidence Half-width (in meters) of positional-uncertainty envelope around this line feature. Data type = float. Null values not permitted; recommend setting value = ?9 if value is not known feet, meters IsoValueLines_PennPerm Symbol References a line symbol in USGS FGDC Digital Cartographic Standard for Geologic Map Symbolization (https://pubs.usgs.gov/tm/2006/11A02/) feet, meters IsoValueLines_PennPerm Label Describes text label for this line feature. Can be used to store fault name or other easily understood name for line feature. Allows for special fonts to show geologic age symbols. Null values are typical feet, meters IsoValueLines_PennPerm DataSourceID Identifies source of each data element. Foreign key to DataSources table. Null values not permitted feet, meters IsoValueLines_PennPerm Notes Optional field. Free text for additional information specific to this feature. Free text for additional information specific to this line feature. Null values permitted feet, meters IsoValueLines_PennPerm IsoValueLines_PennPerm_ID Primary key. Prefix "IVL". Values must be unique in database. Null values not permitted. feet, meters IsoValueLines_RedRiver Type Specifies kind of line feature represented by this database row. Values must be defined in Glossary table. Null values not permitted feet, meters IsoValueLines_RedRiver MapUnit Short, easily understood ASCII-character identifier for the map unit represented by this polygon. Foreign key to DescriptionOfMapUnits table. Use of special characters is discouraged feet, meters IsoValueLines_RedRiver Value_ft Specifies measured value in feet that pertains to this line feature. Date type = float. Null values not permitted feet, meters IsoValueLines_RedRiver Value_m Specifies measured value in meters that pertains to this line feature, value calculated and rounded to the nearest whole number from original value in feet. Date type = float. Null values not permitted feet, meters IsoValueLines_RedRiver ValueConfidence Half-width (in meters) of positional-uncertainty envelope around this line feature. Data type = float. Null values not permitted; recommend setting value = ?9 if value is not known feet, meters IsoValueLines_RedRiver Symbol References a line symbol in USGS FGDC Digital Cartographic Standard for Geologic Map Symbolization (https://pubs.usgs.gov/tm/2006/11A02/) feet, meters IsoValueLines_RedRiver Label Describes text label for this line feature. Can be used to store fault name or other easily understood name for line feature. Allows for special fonts to show geologic age symbols. Null values are typical feet, meters IsoValueLines_RedRiver DataSourceID Identifies source of each data element. Foreign key to DataSources table. Null values not permitted feet, meters IsoValueLines_RedRiver Notes Optional field. Free text for additional information specific to this feature. Free text for additional information specific to this line feature. Null values permitted feet, meters IsoValueLines_RedRiver IsoValueLines_RedRiver_ID Primary key. Prefix "IVL". Values must be unique in database. Null values not permitted. feet, meters IsoValueLines_Triassic Type Specifies kind of line feature represented by this database row. Values must be defined in Glossary table. Null values not permitted feet, meters IsoValueLines_Triassic MapUnit Short, easily understood ASCII-character identifier for the map unit represented by this polygon. Foreign key to DescriptionOfMapUnits table. Use of special characters is discouraged feet, meters IsoValueLines_Triassic Value_ft Specifies measured value in feet that pertains to this line feature. Date type = float. Null values not permitted feet, meters IsoValueLines_Triassic Value_m Specifies measured value in meters that pertains to this line feature, value calculated and rounded to the nearest whole number from original value in feet. Date type = float. Null values not permitted feet, meters IsoValueLines_Triassic ValueConfidence Half-width (in meters) of positional-uncertainty envelope around this line feature. Data type = float. Null values not permitted; recommend setting value = ?9 if value is not known feet, meters IsoValueLines_Triassic Symbol References a line symbol in USGS FGDC Digital Cartographic Standard for Geologic Map Symbolization (https://pubs.usgs.gov/tm/2006/11A02/) feet, meters IsoValueLines_Triassic Label Describes text label for this line feature. Can be used to store fault name or other easily understood name for line feature. Allows for special fonts to show geologic age symbols. Null values are typical feet, meters IsoValueLines_Triassic DataSourceID Identifies source of each data element. Foreign key to DataSources table. Null values not permitted feet, meters IsoValueLines_Triassic Notes Optional field. Free text for additional information specific to this feature. Free text for additional information specific to this line feature. Null values permitted feet, meters IsoValueLines_Triassic IsoValueLines_Triassic_ID Primary key. Prefix "IVL". Values must be unique in database. Null values not permitted. feet, meters DataDictionary.csv GS ScienceBase U.S. Geological Survey mailing address

Denver Federal Center, Building 810, Mail Stop 302

Denver CO 80225 United States 1-888-275-8747 sciencebase@usgs.gov Unless otherwise stated, all data, metadata and related materials are considered to satisfy the quality standards relative to the purpose for which the data were collected. Although these data and associated metadata have been reviewed for accuracy and completeness and approved for release by the U.S. Geological Survey (USGS), no warranty expressed or implied is made regarding the display or utility of the data for other purposes, nor on all computer systems, nor shall the act of distribution constitute any such warranty. Digital Data https://doi.org/10.5066/P14KMRL9 None 20250430 Brooklyn Smout USGS - ROCKY MOUNTAIN REGION Geologist mailing and physical

Denver Federal Center,DFC Bldg 25

Lakewood CO 80225 303-236-1231 bsmout@usgs.gov FGDC Biological Data Profile of the Content Standard for Digital Geospatial Metadata FGDC-STD-001.1-1999