U.S. Geological Survey 20260123 1.0 vector digital data U.S. Geological Survey data release DOI: doi.org/10.5066/P148EEUA Denver, CO U.S. Geological Survey Suggested Citation: U.S. Geological Survey, 2026, National mine waste inventory: U.S. Geological Survey data release, https://doi.org/10.5066/P148EEUA. https://doi.org/10.5066/P148EEUA This U.S. Geological Survey (USGS) data release is a collaborative geospatial database compiled by the USGS and participating State geological surveys, with support from the Earth Mapping Resources Initiative (Earth MRI) program. The database represents the first phase of cataloging above-ground mine waste features —such as tailings and waste rock piles— that are remnants of historical and current mining activities across the nation. These features are potential sources of critical minerals and other metallic commodities that may have been discarded or overlooked. Features in the first version of the database occur in Arizona, Colorado, Kentucky, Michigan, Montana, Nevada, New Mexico, North Carolina, Oklahoma, Utah, and Virginia. These features are represented as points and polygons with attributes describing location, size, commodity, and mineralogy. The entries and descriptions in the database are derived from publicly available sources compiled by USGS and State geological survey partners. This dataset is being developed to increase the understanding of the number, location, size, and other characteristics of non-fuel mine waste features for the conterminous United States. These data are the first version of a national-scale database that is intended to inform and support other Federal, State, and Tribal agencies in land management planning, environmental impact assessments, and prioritizing future research initiatives. The Esri ArcGIS Pro 3.4.3 geodatabase contains one point feature class, one polygon feature class, three non-spatial tables, and six relationship classes. The relationship classes link attribute tables using the Feature ID (Ftr_ID) or Site ID (Site_ID). Spatial and non-spatial tables are duplicated as CSV files. Metadata is provided in extensible markup language (XML), hypertext markup language (HTML), and text-formatted (TXT) formats. A data dictionary summarizes fields in the tables and provides short field descriptions. FILES IN DATA RELEASE --USGS_Mine_Waste-metadata.xml: FGDC metadata --USGS_Mine_Waste-metadata.zip: a folder containing the metadata in XML, HTML, and TXT formats. --USGS_Mine_Waste-metadata-datadict.csv: a non-spatial table summarizing all fields in the geodatabase in alphabetic order. --------USGS_Mine_Waste_US-geodatabase.zip-------- USGS_Mine_Waste.gdb: an Esri file geodatabase containing the following feature classes and tables: -----Relates: six relationship classes that link attribute tables. -----Waste_Points: a point feature class that represents the approximate center of mine waste polygons and contains basic information about the location. -----Waste_Polygons: a polygon feature class that represents the extent of mine waste features. -----Waste_Geology: a table that contains reported deposit type, commodity, and minerals associated to the waste feature. -----Waste_References: a table that contains the citation document(s) from which the point, polygon, or attribute information was obtained. -----Waste_Resources: a table that contains reported resource information for mine waste features. ------USGS_Mine_Waste-shapefiles.zip---------- A zip file containing shapefiles of feature classes and CSV versions of non-spatial tables in the file geodatabase. Also includes a data dictionary and metadata. Zip file contains: --USGS_Mine_Waste-metadata: a folder containing the metadata in XML, HTML, and TXT formats. --USGS_Mine_Waste-shapefiles: a folder containing shapefiles of the GIS data and comma-separated values (CSV) tables. --USGS_Mine_Waste-metadata-datadict.csv: a non-spatial table that summarizes all fields represented in the geodatabase, presented in alphabetic order. GENERAL INFORMATION Mine waste features are man-made features which are the result of extracting, processing, and/or concentrating mining-related materials. The locations of mine waste features are commonly represented as polygons or points in source maps, figures, reports, tabular data, or GIS layers. In this database, mine waste features are represented by a polygon boundary showing the surficial extent of a mine waste feature as determined from published reports or from digital GIS datasets, and a point feature that represents the approximate center of the polygon extent. Each polygon and point feature are uniquely identified by a feature ID. The site ID is used to indicate groups of related features, or "sites". Tables are linked (related) using the Feature ID (Ftr_ID) or the Site ID (Site_ID) fields. Some tables have more than one record describing a feature. For example, a point denoting a mine waste feature location may have many records in the Waste_Resources table which may provide mine waste characterization information reported for multiple materials (for example, copper, lead, and zinc). The database is designed to allow the user to navigate from the polygon or point layers to the linked table information or from the tables to the polygon and point layers. All information is derived from publicly available sources. Full citations are listed in the References table Citation (Citation) field, and each full citation is assigned a short citation that is recorded in the Primary Citation (Prim_Cit) or Secondary Citation (Sec_Cit) fields in the attribute tables. Secondary citations are enumerated after attribute field values, which are referred to as secondary citation designators, and the corresponding citation is reported in the Secondary Citation (Sec_Cit) field. As an example, one Commodity record shows "copper; gold (1); silver (1)". This indicates that identification of the commodity "copper" is derived from the primary citation denoted in the Primary Citation (Prim_Cit) field as "Duhamel and others (1995)" and "gold (1); silver (1)" are derived from the first reference in the Secondary Citation (Sec_Cit) field as "(1) Werner and others (2017)". Secondary citations are reported in the order of use in the attribute table after the primary citation. The Last Updated (Last_Updt) field shows the date that the record was last updated. Text fields may report text strings, such as those seen in the Commodity (Commodity) field. Commodity values are reported in alphabetical order, not order of importance, and are separated by a semicolon. There are no ending periods for text strings, except for the Reference (Reference) field. In Esri ArcGIS Pro, null values in the attribute table indicate where available data were checked and no data were found to populate the cell. In these cases, the attribute value will display "<Null>". In csv files, the cell value will appear empty. In the Entity and Attribute section of this metadata, attribute fields from all feature classes and tables are listed in alphabetical order, and corresponding feature classes and tables are listed in parentheses after the field name in the Attribute Label. For example, "Commodity (Waste_Geology, Waste_Points)" indicates that the attribute field Commodity (Commodity) occurs in the Waste_Geology table and in the Waste_Points table. DATABASE LAYERS AND TABLES EXPLANATION In the geospatial database, all non-fuel mine waste features are represented as polygons that contain a central point. The perimeters of waste features are obtained from published reports or from digital GIS datasets. These perimeters are compared to current GIS imagery and updated as needed to reflect any discernable changes to the waste feature on the landscape. The central point located inside each polygon provides a single latitude and longitude coordinate for each mine waste feature plus additional information about the waste feature. Waste Polygons (Waste_Polygons) The Waste_Polygons feature class contains polygons or footprints of non-fuel mine waste features. These polygons are digitized from public documents or imported from digital GIS datasets. Polygons may be subsequently refined using imagery and/or digital elevation models to capture the current spatial extent of the feature. Attributes are captured for site and feature name, feature type, and a description of how the feature was located. The polygon feature is related to the point and resource record by the Feature ID (Ftr_ID) field and to the geology record by the Site ID (Site_ID) field. All information in the attribute record is derived from the citation(s) reported in the Primary Citation (Prim_Cit) and Secondary Citation (Sec_Cit) fields. These citations are reported in the Reference table Citation (Citation) field. Waste Points (Waste_Points) The Waste_Points feature class contains point locations that represent the approximate center of the related polygon feature. All features have an associated point record in the database. The point attribute table reports general locational information (State, County, Longitude, Latitude, and other things), commodity(s), and the mine and/or district the waste feature is associated with. The point feature is related to the polygon and resource record by the Feature ID (Ftr_ID) field, and to the geology record by the Site ID (Site_ID) field. Waste Resources (Waste_Resources) The Waste_Resources attribute table reports known mineral resource characterization information for the mine waste feature. This may include volume, tonnage factor, material amount, grade, or contained commodity information. In many cases, little is known about mineral resources, so these entries may be sparsely populated. Individual waste features may have multiple records in the resource table, or a one-to-many relationship. For example, if a publicly available source reports that a waste feature has copper, lead, and zinc, all with tonnage and grade, there would be a minimum of three records in the resource table, one for each reported material. There may be more than three records for this example if the characterization included resource classifications, such as inferred or indicated resources. There are two primary divisions of the waste resources attribute table: 1) reported information, where no conversions or calculations are reported; 2) International System of Units (SI) information, where all reported values are reported in SI, and when appropriate, calculations by USGS staff are completed to fill in the gaps in the records. The USGS reports first order approximation for the volume of all mine waste features. These volumes are estimated using a linear regression method that uses the areal extent of the waste feature and the minimum and maximum elevations derived from digital elevation model data. This value is reported in the Calculated Volume (Calc_Vol) field, where units are in cubic meters. Calculated volumes are not used in other calculations to fully populate records. These values may not compare well with reported volumes given possible dimensional changes to the features over time since the volumes were reported in literature. The SI fields - Reported Volume SI (Rep_Vol_SI), Tonnage Factor SI (Ton_F_SI), Material Amount SI (MatAmntSI), Grade SI (GradeSI), and Contained SI Commodity Amount (CntSIComAm) are populated by USGS staff where possible. These conversions and calculations allow resource values to be reported in standard units, and gaps in the database to be filled. Values ending with “111” as a decimal trailer, indicate the value was calculated by USGS staff. For example, if the value in the Tonnage Factor SI (Ton_F_SI) field is calculated by USGS staff to be 1.8 metric tons per cubic meter, the value recorded in the database will be 1.8111. Converted values will also use this format. For example, if a value in the Material Amount SI (MatAmntSI) field is converted by USGS staff to be 450,000 metric tons, the value recorded in the database will be 450,000.111. These decimal trailers are not reported in the Entity and Attribute section of this metadata for numeric ranges. Additionally, values may be reported with a preceding negative sign to indicate values that apply to multiple records. For example, if the volume of a waste feature contains copper, lead, and zinc, and the grade and tonnage are reported, the table will have a record for each commodity, and the volume of each will be the same and will include a negative sign. Waste resource records are related to the polygon and point feature by the Feature ID (Ftr_ID) field and to the geology record by the Site ID (Site_ID) field. Waste Geology (Waste_Geology) The Waste_Geology attribute table reports known information for deposit type, commodity, and minerals related to the geologic source of the mine waste. Geology records are generally reported at a broader site level since there typically is little published information on the composition of materials in individual waste features. If it is known that features within a site have variable material compositions, there may be more than one geology record to a site, where the Feature ID (Ftr_ID) field will designate the geology record specific to the feature. Terms in text strings for Deposit Type 2 (Dep_Type_2), Ore Minerals (Ore_Min), and Gangue Minerals (Gangue_Min) fields are listed alphabetically and are delimited by a semicolon. Waste geology records are related to the polygon, point, and resource records by the Site ID (Site_ID) field. Waste References (Waste_References) The Waste_References table provides full references in USGS format for all citations used in the database. This is a stand-alone table which is not related to any other table in the database. 1905 2025 publication dates of source information Planned Irregular -124.7625 -66.9496 49.3845 24.5211 ISO 19115 Topic Category geoscientificInformation USGS Thesaurus aluminum antimony arsenic barite beryllium bismuth cobalt copper critical minerals economic geology fluorite geographic information systems geospatial datasets gold hafnium iron lead lithium magnesium manganese metallic mineral resources mine waste mineral deposits mineral resources mineralogy mining and quarrying molybdenum nickel palladium platinum rhenium silver tellurium tin titanium tungsten uranium vanadium zinc zirconium none Department of the Interior DOI Energy and Minerals Mission Area EMMA Rocky Mountain Region USGS Region 7 U.S. Geological Survey USGS Geology, Geophysics, and Geochemistry Science Center GGGSC Mineral Resources Program MRP Earth Mapping Resources Initiative Earth MRI USGS Mineral Deposit Database USMIN none commodities deposit deposit type evaporation pond gangue minerals gypsum stack leach pile mine dump mining district ore minerals ore stockpile overburden pile phosphate pond potash settling pond slag pile tailings waste rock stockpile USGS information products data release USGS Metadata Identifier USGS:686317a5d4be025653d31f09 Common Geographic Areas United States Arizona Colorado Kentucky Michigan Montana Nevada New Mexico North Carolina Oklahoma Utah Virginia None. Please see 'Distribution Info' for details. Any use of trade, firm, or product names is for descriptive purposes only and does not imply endorsement by the U.S. Government. Although these data have been processed successfully on a computer system at 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. The USGS or the U.S. Government shall not be held liable for improper or incorrect use of the data described and/or contained herein. Nick A Karl U.S. Geological Survey Supervisory Physical Scientist mailing and physical

PO Box 25046

Mail Stop 973

Lakewood CO 80225 US 303-236-1222 nkarl@usgs.gov The data sets were developed by the U.S. Geological Survey Geology, Geophysics, and Geochemistry Science Center (GGGSC) with funding from the U.S. Geological Survey Mineral Resources Program (MRP) and the Earth Mapping Resources Initiative (Earth MRI). USGS contributors were Autumn L. Helfrich, Carma A. San Juan, Elizabeth M. Smith, John A. Murzyn, Karissa G. Rosenberger, Nick A. Karl, Ryan D. Taylor, and Sean P. Gaynor. Former USGS contributors were Abby S. Buarapha, Alan A. Hurlbert, Andrew F. Smith, Cheryl Novakovich, Christina N. Hutchins, Emma Boardman-Larson, Emma J. Haydamack, Jacob D. Melendez, Jeffrey L. Mauk, Jonathan Funk, Justin S. Pierson, Laura C. Dair, Madelyn E. Eysel, Sophia Pinter, Ursula E. Armstrong-Sturges, and Virgil S. Alfred. State geological survey contributions were made by: Kentucky Geological Survey, Michigan Geological Survey, Montana Bureau of Mines and Geology, Nevada Bureau of Mines and Geology, North Carolina Geological Survey, Oklahoma Geological Survey, and Virginia Department of Energy, Geology and Mineral Resources Program. Data and metadata review were provided by Josh M. Rosera of the U.S. Geological Survey. Environment as of Metadata Creation: Microsoft Office 365 ProPlus; Esri ArcGIS Pro 3.4.3 Unique values in text attribute fields were checked through frequency analyses for spelling, consistency of terms, accuracy, adherence to established vocabularies, and completeness. Numeric values were reviewed and verified by USGS staff. In published reports, numeric values are reported with variable precision. Numeric values that have trailing zeros after the decimal are truncated in ArcGIS. For example, a Grade (Grade) value reported as 0.370 is stored as 0.37 in the ArcGIS table. The published Grade (Grade) is provided in the Remarks (Remarks) field. The CSV version of the ArcGIS attribute tables will reflect the contents of the geodatabase table. A feature in this database is a spatially unique mine waste entity represented by a point and a polygon. The locations of mine waste features are represented as polygons in the Waste_Polygons, and as points in the Waste_Points feature classes. The polygonal footprint represents the approximate outline of a mine waste feature. These features are identified in cited literature reported in the Primary Citation (Prim_Cit) and/or the Secondary Citation (Sec_Cit) fields. Spatial extents are refined using imagery, digital elevation models or similar to allow the estimation of the current spatial extent of the feature. The point represents the approximate center of the polygon feature. Features reported in the polygon and point feature classes are related to records in the Waste_Resources table by the Feature ID (Ftr_ID), and to the Waste_Geology table by the Site ID (Site_ID). A site is considered a grouping of features but may also consist of an individual feature. Polygon features do not overlap and point features are not co-located or “stacked”. In rare circumstances polygonal features are represented as a multipart polygon if the volume, material amount, grade or similar are reported for a feature that has spatially separated parts. Polygon features may be merged if they are within 100 meters of another similar feature type given there is not a significant change in elevation. All features in this database have a polygon record, a point record, and a resource record at the feature level and a geology record that represents the grouping of features at the site level. Non-fuel mine waste feature geospatial and attribute data are compiled for Arizona, Colorado, New Mexico, and Utah by USGS staff, where features captured are larger than 200,000 square meters in area. Mine waste features captured by State geological surveys for Kentucky, Michigan, Montana, Nevada, North Carolina, Oklahoma, and Virginia are larger than 2,000 square meters in area. Data are limited to publicly available sources which were found to be reported for the time period between 1905 and 2025. Common literature sources include industry reports, mining technical reports, journal articles, and Federal and State agency reports or databases. Locations of features are compiled by importing published geographic information system (GIS) data or by digitizing georeferenced images of maps, and then using imagery, or digital elevation models to refine shape extents. The locational accuracy of features is dependent on the accuracy of the source GIS, maps, or similar that were imported or digitized in the database. USGS 3D Elevation Program (3DEP) 1/3 arc-second (approximately 10-meter resolution) seamless Digital Elevation Model (DEM) data were used in the calculation of mine waste volumes. 3DEP reports that as of 2022, the absolute vertical accuracy of 1/3 arc DEM within the conterminous United States is approximately 0.82 meters root mean square error (RMSE), and is based on a comparison to almost 25,000 NOAA National Geodetic Survey Online Positioning User Service (OPUS) points. Vertical accuracy varies significantly across the U.S. because of differences in source quality, terrain relief, land cover, and other factors. Vertical measurements are based on the North American Vertical Datum of 1988 (NAVD88). See https://www.usgs.gov/faqs/what-vertical-accuracy-3d-elevation-program-3dep-dems for further information. Esri 2025 application/service Suggested citation: Esri, 2025, World imagery: Esri, https://services.arcgisonline.com/ArcGIS/rest/services/World_Imagery/MapServer. https://services.arcgisonline.com/ArcGIS/rest/services/World_Imagery/MapServer Online map service 2025 publication date Esri (2025) A primary natural color landscape imagery layer used to refine the perimeters of mine waste polygon features. Imagery data are from TerraColor satellite and aerial Maxar imagery at 0.3-meter resolution for select metropolitan areas around the world, and 0.5-meter resolution across the United States. John D Horton Carma A San Juan 2016 vector digital data Suggested citation: Horton, J.D., and San Juan, C.A., 2016, Prospect- and mine-related features from U.S. Geological Survey 7.5- and 15-minute topographic quadrangle maps of the United States (ver. 10.0, May 2023): U.S. Geological Survey data release, https://doi.org/10.5066/F78W3CHG. https://doi.org/10.5066/f78w3chg Digital and/or Hardcopy 1886 2006 Topographic map publication date Horton and San Juan (2016) These data were used to identify locations and mine waste feature types in the development of the dataset. In addition, this source was used by the authors to develop standardized vocabularies of waste feature types for the database and attribute tables. U.S. Geological Survey 2019 raster digital data Suggested citation: U.S. Geological Survey, 2019, USGS 3D Elevation Program Digital Elevation Model: U.S. Geological Survey, accessed October 17, 2022, at https://elevation.nationalmap.gov/arcgis/rest/services/3DEPElevation/ImageServer. https://elevation.nationalmap.gov/arcgis/rest/services/3DEPElevation/ImageServer Digital and/or Hardcopy 2019 publication date U.S. Geological Survey (2019) A 1- to 10-meter resolution digital elevation model (DEM) layer used to generate hill shade images to refine the perimeters of mine waste polygon features. These DEM data were also used to extract the minimum and maximum elevations of mine waste features to estimate the volume of waste. American Geosciences Institute 1997 2 publication American Geosciences Institute, 1997, Dictionary of mining, mineral, and related terms (2nd ed.): Alexandria, Va., American Geosciences Institute, 646 p. Digital and/or Hardcopy 1997 publication date American Geosciences Institute (1997) Reference used by the staff to develop standardized vocabularies for the database and attribute tables. The use of this reference is denoted as American Geosciences Institute (1997) in this metadata. Canadian Institute of Mining, Metallurgy and Petroleum 2014 publication Canadian Institute of Mining, Metallurgy and Petroleum, 2014, CIM definition standards for mineral resources & mineral reserves: Canadian Institute of Mining, Metallurgy and Petroleum, 9 p., accessed May 4, 2020, at https://mrmr.cim.org/media/1128/cim-definition-standards_2014.pdf. https://mrmr.cim.org/media/1128/cim-definition-standards_2014.pdf Digital and/or Hardcopy 2014 publication date Canadian Institute of Mining, Metallurgy and Petroleum (2014) Reference used by the staff to develop standardized vocabularies for the database and attribute tables. The use of this reference is denoted as Canadian Institute of Mining, Metallurgy and Petroleum (2014) in this metadata. Committee for Mineral Reserves International Reporting Standards 2024 publication Committee for Mineral Reserves International Reporting Standards, 2024, RIRSCO Definitions, 22 p., accessed July 17, 2025, at https://crirsco.com/wp-content/uploads/woocommerce_uploads/2025/07/CRIRSCO_Definitions_Summary_to_accompany_June2024_version_of_the_CRIRSCO_Template-6c3lij.pdf. https://crirsco.com/wp-content/uploads/woocommerce_uploads/2025/07/CRIRSCO_Definitions_Summary_to_accompany_June2024_version_of_the_CRIRSCO_Template-6c3lij.pdf Digital and/or Hardcopy 2024 publication date Committee for Mineral Reserves International Reporting Standards (2024) Reference used by the USGS staff to develop standardized vocabularies for the database and attribute tables. The use of this reference is denoted as Committee for Mineral Reserves International Reporting Standards (2024) in this metadata. Bureau of Land Management 2025 application/service Bureau of Land Management, 2025, BLM National SMA Surface Management Agency Area Polygons: Bureau of Land Management database, accessed July 15, 2025, at https://www.arcgis.com/sharing/rest/content/items/6bf2e737c59d4111be92420ee5ab0b46/info/metadata/metadata.xml?format=default&output=html. https://www.arcgis.com/sharing/rest/content/items/6bf2e737c59d4111be92420ee5ab0b46/info/metadata/metadata.xml?format=default&output=html Digital and/or Hardcopy 2025 publication date Bureau of Land Management (2025) Reference used by USGS staff to develop standardized vocabularies for the database and attribute tables. The use of this reference is denoted as Bureau of Land Management (2025) in this metadata. Albert Hofstra Vladimir Lisitsin Louise Corriveau Suzanne Paradis Jan Peter Kathleen Lauzière Christopher Lawley Michael Gadd Jean-Luc Pilote Ian Honsberger Evgeniy Bastrakov David Champion Karol Czarnota Michael Doublier David Huston Oliver Raymond Simon VanDerWielen Poul Emsbo Matthew Granitto Douglas Kreiner 2021 publication Hofstra, A., Lisitsin, V., Corriveau, L., Paradis, S., Peter, J., Lauzière, K., Lawley, C., Gadd, M., Pilote, J., Honsberger, I., Bastrakov, E., Champion, D., Czarnota, K., Doublier, M., Huston, D., Raymond, O., VanDerWielen, S., Emsbo, P., Granitto, M., and Kreiner, D., 2021, Deposit classification scheme for the Critical Minerals Mapping Initiative Global Geochemical Database: U.S. Geological Survey Open-File Report 2021–1049, 60 p., https://doi.org/10.3133/ofr20211049. https://doi.org/10.3133/ofr20211049 Digital and/or Hardcopy 2021 publication date Hofstra and others (2021) Reference used by USGS staff to develop standardized vocabularies for the database and attribute tables. The use of this reference is denoted as Hofstra and others (2021) in this metadata. The U.S. Geological Survey compiled mine waste features related to non-fuel commodities for Arizona, Colorado, New Mexico, and Utah. A search of publicly available mine waste information was conducted for mine waste features greater than 200,000 square meters in areal extent. The size cutoff applies to individual features at a site. Sites with numerous smaller mine waste features, like Leadville, CO, were not captured. Priority was given to using existing national coverage databases which provide mine waste feature locations and attribute information suitable for a geographic information system (GIS). Four primary sources of information were evaluated for waste feature identification. They include GRID-Arendal (2020), Horton and San Juan (2016), U.S. Army Corps of Engineers (2020), and U.S. Environmental Protection Agency (2024). Literature research identified additional attribute information for these features. Relevant information was acquired, reviewed for quality and geospatial information, digitally captured, and fully attributed to the extent possible. Mine waste features identified in published datasets or literature were captured in the GIS as a polygon feature type. The perimeters of these features were evaluated using 0.3- to 0.5-meter resolution natural color imagery (Esri, 2025) as well as 1- to 10-meter resolution shaded relief imagery (U.S. Geological Survey, 2019). In many cases, waste feature perimeters were modified to reflect landscape changes. In most cases, these features represent individual waste entities. Situationally, features may have been merged if they were within 100 meters of another similar feature type, and if there were not significant elevation changes between the features. If a feature was named, and reported resource characterization information was provided, such as a reported volume, those features were not merged with neighboring features in order to preserve the original reporting information as best as possible. A point feature was then placed in the approximate center of the associated polygon feature. The point feature was attributed to provide a single latitude and longitude coordinate for each mine waste feature plus associated information such as feature type, commodity, land management agency, Superfund status, and other things. Known mine waste resource information is reported for each feature. Information was compiled as reported and consequently reported in variable units. For consistency, the USGS converted these values to International System of Units (SI). USGS staff made every attempt to provide SI material amount, grade, and contained values. If two of the three values were reported, the missing value was calculated by the USGS staff in SI fields. These fields are denoted by "SI" in the field name. Values that have been converted or calculated in SI fields are denoted by a “111” decimal trailer. The USGS estimated a first order approximation of volumes for each feature using a linear regression method (Hollister and Milstead, 2010) and 10-meter resolution DEM data for minimum and maximum elevations. Volumes with null values indicate the area of the mine waste feature was too small for the tool to calculate. Geology is generally provided at the site level. There may be instances where geology within a site is unique at the feature level. In these instances, there may be more than one geology record per site, but this is uncommon. Otherwise, a single geology record per site is required, which includes information on the deposit type, commodity, ore, and gangue minerals. These attributes are based on the source of the mine waste feature(s). All data were spatially integrated using ArcGIS. All attribute data were compiled from publicly available sources published between 1905 and 2025. Data were checked throughout the compilation process for accuracy of locations, completeness, and accuracy and consistency of attribution. State geological surveys completed an in-person training and two-review cycles prior to submitting final records to be included in the mine waste inventory. States completed work based on proposals through Earth MRI, which may not be inclusive of all mine waste features for the State. Once final data were submitted to USGS, USMIN staff evaluated submissions to ensure data were captured and attributed as these metadata describe. GRID-Arendal, 2020, Global tailings portal: GRID-Arendal database, accessed December 2022, https://tailing.grida.no/. Hollister, J., and Milstead, W.B., 2010, Using GIS to estimate lake volume from limited data: Lake and Reservoir Management, v. 26, no. 3, p. 194-199, https://doi.org/10.1080/07438141.2010.504321. U.S. Army Corps of Engineers, 2020, National Inventory of Dams: U.S. Army Corps of Engineers, accessed January 31, 2023, at https://nid.sec.usace.army.mil/#/. U.S. Environmental Protection Agency, 2024, NPL superfund site boundaries (EPA public): U.S Environmental Protection Agency, accessed December 13, 2024, at https://services.arcgis.com/cJ9YHowT8TU7DUyn/arcgis/rest/services/FAC_Superfund_Site_Boundaries_EPA_Public/FeatureServer. Esri (2025) Horton and San Juan (2016) U.S. Geological Survey (2019) 20250201 Vector G-polygon 764 Albers Conical Equal Area 20.0 60.0 -96.0 40.0 0.0 0.0 coordinate pair 0.6096 0.6096 meters North_American_Datum_1983 GRS 1980 6378137.0 298.257222101 Attribute Fields The attribute fields contain attribute information associated with features or records in the data set. Attribute fields occur in data layer(s) noted in parentheses. USGS staff Area_SqKm (Waste_Polygons) Area Square Kilometers: area of the feature reported in square kilometers. USGS staff 0.000424 20.799310 square kilometer 0.000001 Calc_Vol (Waste_Resources) Calculated Volume: volume calculated by USGS. Associated units are reported in Calculated Volume Units (Calc_V_Ut). USGS staff 416 1,892,567,584 cubic meters 1.0 Calc_V_Ut (Waste_Resources) Calculated Volume Units: the Calculated Volume (Calc_Vol) units reported in cubic meters. USGS staff An example for this field is "cubic meters". Citation (Waste_References) Citation: shortened version of the reference reported in Primary Citation (Prim_Cit) or Secondary Citation (Sec_Cit). The citation includes author(s) name and publication year. USGS staff An example for this field is "Karl and others (2022)". CntSIComAm (Waste_Resources) Contained SI Commodity Amount: amount reported in the Contained field converted to metric tons, where associated units are reported in the Contained SI Commodity Unit (CntSIComUt) field. If the Material is reported as a compound, USGS staff convert to the elemental amount using stoichiometry. USGS staff 0.003 2,800,000 See CntSIComUt CntSIComod (Waste_Resources) Contained SI Commodity: contained commodity in the reported material. Reported as an element or chemical compound. USGS staff Ag Silver USGS Staff Au Gold USGS Staff Bi Bismuth USGS staff Co Cobalt USGS staff Cu Copper USGS staff Fe Iron USGS staff Ga Gallium USGS staff Pb Lead USGS staff Te Tellurium USGS staff W Tungsten USGS staff Zn Zinc USGS staff Zr Zirconium USGS staff CntSIComUt (Waste_Resources) Contained SI Commodity Units: the Contained SI Commodity Amount (CntSIComAm) units reported in metric tons. USGS staff An example for this field is "metric tons". Commodity (Waste_Geology, Waste_Points) Commodity: produced commodity(s) reported by the source mine or the mining district. USGS staff An example for this field is "copper; gold; silver". Contained (Waste_Resources) Contained: contained commodity amount reported for the waste feature. Associated units are reported in the Contained Units (ContUnits) field. The Contained value is associated to the reported Material. If the Material is a compound, the Contained value represents the contained compound. If the Material reported is an elemental commodity, the Contained value represents the elemental form of the commodity. USGS staff 300 257,400,000 See ContUnits ContUnits (Waste_Resources) Contained Units: units of the Contained commodity. USGS staff kilograms The SI base unit for mass. USGS staff pounds A U.S. customary unit of mass equal to 16 ounces. USGS staff short ton units A unit of mass equal to 2000 pounds. USGS staff County (Waste_Points) County: name of the U.S. County where the feature is located. The attribution is based on the point location. USGS staff An example for this field is "Grant". DEM_Date (Waste_Resources) Digital Elevation Model Date: publication year of the digital elevation model used for the volume calculation. USGS staff An example for this field is "2024". Dep_Type_1 (Waste_Geology) Primary Deposit Type: primary reported deposit type for the site and (or) feature. Classifications are modified from Hofstra and others (2021). USGS staff An example for this field is "Calc-alkaline porphyry copper". Dep_Type_2 (Waste_Geology) Other Deposit Type(s): other reported deposit types for the site and (or) feature. Classifications are modified from Hofstra and others (2021). USGS staff An example for this field is "Skarn; Supergene". Ftr_ID (Waste_Geology, Waste_Points, Waste_Polygons, Waste_Resources) Feature ID: a unique alpha-numeric value assigned to each feature. The identifier includes the Site ID (Site_ID). USGS staff An example for this field is "NM000001-001". Ftr_Name (Waste_Geology, Waste_Points, Waste_Polygons, Waste_Resources) Feature Name: known name of the feature. USGS staff An example for this field is "Tailings Impoundment No. 1". Ftr_Type (Waste_Points, Waste_Polygons) Feature Type: type of waste feature. USGS staff Evaporation pond An artificial pond with very large surface areas that are designed to efficiently evaporate water by sunlight and exposure to ambient temperatures. American Geological Institute (1997) Gypsum stack Features of gypsum, or phosphogypsum waste piles as a result of phosphate mining. USGS staff Leach pile - dump A process in hydrometallurgy by which a lixiviant is added to broken waste rock heaped on the surface. USGS staff Leach pile - heap A process in hydrometallurgy by which a lixiviant is added to broken ore heaped on the surface. USGS American Geological Institute (1997) Leach pile - unknown The feature is a leach dump or heap, but it is not clearly known as to which it should be classified as. USGS staff Mine dump A pile of material excavated from a mine and then transported and dumped in a heap or pile at or near a mine opening or open pit. Also called a waste dump, heap, pile, or spoil pile. American Geological Institute (1997) Ore stockpile/storage A location where ore materials are stored as piles after being removed from the mine and before being processed. The material is then transported to a process plant or site. American Geological Institute (1997) Other Other feature type. Where a description is reported in the Remarks field. USGS staff Overburden pile Barren rock material, either loose or consolidated, overlying a mineral deposit, which was removed prior to mining. American Geological Institute (1997) Phosphate pond Ponds related to phosphate mining which may include surge ponds, cooling ponds, liming ponds or similar. USGS staff Settling pond A basin used to allow solids to settle out of waste water. May also be known as settling area. USGS staff Slag pile A pile of slag which is waste from the smelting of ore. American Geological Institute (1997) Tailings - dredge Sand and gravel that was mined and processed by a dredge. Dredge tailings typically occur as regularly spaced, curved mounds of sand and gravel in streambeds. American Geological Institute (1997) Tailings - mill The gangue and other refuse material resulting from the washing, concentration, or treatment of ground ore. American Geological Institute (1997) Tailings - placer Undifferentiated placer tailings include mounds and curved rills (material rolled down a slope) of sand and gravel that were mined and processed by placer methods. American Geological Institute (1997) Tailings - pond An area closed at the lower end by a constraining wall or dam into which tailings, mineral processing waste, containing a high proportion of water are deposited. The pond is generally impounded with a dam, referred to as a tailings dam. Also known as tailings impoundments, or tailings storage facilities. American Geological Institute (1997) Tailings - undifferentiated The gangue and other refuse material resulting from the washing, concentration, or other treatment of ground ores. Also called slimes, tails, refuse, and leach residue. Generally differentiated from mine dumps on topographic maps by label only. American Geological Institute (1997) Waste rock stockpile Rock or ore that has been mined and stockpiled for later use. Identified as waste rock stockpile, or waste stockpile in literature. USGS staff Gangue_Min (Waste_Geology) Gangue Minerals: minerals identified in the cited reference(s) that were not economically desirable. In most cases, these minerals do not contain a commodity from the commodity list. USGS staff An example for this field is "biotite; calcite; chlorite; epidote; orthoclase; pyrite; quartz". Grade (Waste_Resources) Grade: reported grade of the waste feature Material. Associated units are reported in the Grade Units (Grade_Units) field. This is not the deposit grade, but the grade of the waste feature material. USGS staff 0.005 543.15 See Grade_Units Grade_Units (Waste_Resources) Grade Units: units of Grade. USGS staff parts per million The numeric units of mass of element per million units of total mass. USGS staff percent Numeric value expressed on the basis of a proportion per hundred. USGS staff troy ounces per short ton A unit of grade defined by mass in troy ounces divided by mass in short tons. USGS staff GradeSI (Waste_Resources) Grade SI: amount reported in the Grade field converted to International Systems of Units (SI). Associated units are reported in the Grade Units SI (GradeUntSI) field. USGS staff 0.02 543.15 See GradeUntSI GradeUntSI (Waste_Resources) Grade Units SI: Units of Grade SI (GradeSI). USGS staff grams per metric ton Numeric value expressed as mass in grams divided by mass in metric tons. USGS staff parts per million The numeric units of mass of element per million units of total mass. USGS staff percent Numeric value expressed on the basis of a proportion per hundred. USGS staff Land_Mng (Waste_Points) Land Management: surface management agency identified using the Bureau of Land Management National Surface Management Agency geodatabase (Bureau of Land Management, 2024). Attribution is based on the polygon extent. USGS staff DOD-USACE Department of Defense United States Army Corp of Engineers Bureau of Land Management (2025) DOI-BIA Department of Interior Bureau of Indian Affairs Bureau of Land Management (2025) DOI-BLM Department of Interior Bureau of Land Management Bureau of Land Management (2025) DOI-NPS Department of Interior National Park Service Bureau of Land Management (2025) PVT Private Bureau of Land Management (2025) ST State Bureau of Land Management (2025) UND Undetermined Bureau of Land Management (2025) USDA-USFS United States Department of Agriculture United States Forest Service Bureau of Land Management (2025) Last_Updt (Waste_Geology, Waste_Points, Waste_Polygons, Waste_References, Waste_Resources) Last Updated: date the record was last updated. USGS staff An example for this field is "2024-10-28". Latitude (Waste_Points) Latitude: latitude of point feature in decimal degrees, North American Datum 1983. USGS staff 31.385907 47.935318 decimal degrees 0.000001 Loc_Descr (Waste_Polygons) Location Description: description of how the feature was located. USGS staff An example for this field is "Digitized polygon using Esri (2024) (1)" where the primary citation located the feature and then was digitized using Esri imagery to reshape the feature to represent the current landscape. The "(1)" indicates that this is a secondary citation that is reported in the Secondary Citation (Sec_Cit) field. Longitude (Waste_Points) Longitude: longitude of point feature in decimal degrees, North American Datum 1983. USGS staff -119.397898 -76.714664 decimal degrees 0.000001 Mat_Amnt (Waste_Resources) Material Amount: reported Material amount in the waste feature. Associated units are reported in the Material Units (Mat_Units) field. USGS staff 18,200 1,903,000,000 See Mat_Units Mat_Type (Waste_Resources) Material Type: type of material reported. Material type is equivalent to Feature Type (Ftr_Type) reported in the Waste_Polygons and Waste_Points feature classes. USGS staff An example for this field is "Tailings - pond". Material types are the same as feature types. Please see the field Ftr_Type for a full list of definitions. Mat_Units (Waste_Resources) Material Units: units of the Material Amount (Mat_Amnt). USGS staff kilograms The SI base unit for mass. USGS staff metric tons An SI unit of mass equal to 1,000 kilograms. USGS staff short tons A U.S. customary unit for mass that is equal to 2,000 pounds. USGS staff MatAmntSI (Waste_Resources) Material Amount SI: amount reported in the Material Amount (Mat_Amnt) field converted to the International System of Units (SI) of metric tons. USGS staff 16,500 1,903,000,000 metric tons Material (Waste_Resources) Material: material reported by the source document. Material may be reported in elemental or compound form. USGS staff An example for this field is "titanium (Ti)" when reporting in elemental form, or "rutile (TiO2)" when reporting in compound form. MatUnitSI (Waste_Resources) Material Units SI: the Material Amount SI (MatAmntSI) units reported in metric tons. USGS staff An example for this field is "metric tons". Mine_Name (Waste_Points) Mine Name: name of the mine associated to the feature. USGS staff An example of this field is "Tyrone Mine". Mine_Dist (Waste_Points) Mining District: name of the mining district, mineral district, area, region, belt, or similar that is related to the source material. USGS staff An example of this field is "Burro Mountains". Ore_Min (Waste_Geology) Ore Minerals: mineral(s) identified in the cited reference(s) that is a commodity, or contains an element from the Commodity field, that could be economically viable for production and recovery. USGS staff An example of this field is "chalcopyrite; molybdenite". Where the commodities of copper and molybdenum are reported. Other Names (Waste_Points) Other Names: other reported names of the mine waste feature. USGS staff An example of this field is "Tailing Pond 6E; Tailing Pond 6W". Prim_Cit (Waste_Geology, Waste_Points, Waste_Polygons, Waste_Resources) Primary Citation: shortened version of the primary citation. Identification includes author name(s) and publication year. USGS staff An example of this field is "Simmons (2013)" for a single author, "North and McLemore (1986)" for two authors, and "McLemore and others (2021)" for more than two authors. Reference (Waste_References) Reference: full reference of the associated Citation. USGS staff An example of this field is "McLemore, V.T., 2017, Mining districts and prospect areas in New Mexico: New Mexico Bureau Mines Mineral Resources Resource Map 24, 65 p., https://doi.org/10.58799/RM-24.". Reclaimed (Waste_Points) Reclaimed: value that indicates if a waste feature has been fully reclaimed. USGS staff An example of this field is "Yes" if the feature has been fully reclaimed, and "No" if the feature has been partially reclaimed, or has not undergone reclamation. Remarks (Waste_Geology, Waste_Points, Waste_Polygons, Waste_Resources) Remarks: field that contains general remarks not accommodated by the data structure. USGS staff An example of this field is "Deposit known as Santa Rita". Rep_Vol (Waste_Resources) Reported volume: reported volume of the waste feature. Associated units are reported in the Reported Volume Units (Rep_V_Ut) field. USGS staff 400,000 1,562,000,000 See Rep_V_Ut Rep_Vol_SI (Waste_Resources) Reported Volume SI: amount reported in the Reported Volume (Rep_Vol) field converted to International System of Units (SI). Associated units are reported in the Reported Volume Units SI (Rep_Vut_SI) field. USGS staff 300,000 1,562,000,000 See Rep_Vut_SI Rep_V_Ut (Waste_Resources) Reported Volume Units: units of the Reported Volume (Rep_Vol). USGS staff cubic feet A unit of volume of a cube with edges of one foot in length. USGS staff cubic meters An SI unit of volume of a cube with edges of one meter in length. USGS staff cubic yards A unit of volume of a cube with edges of one yard in length. USGS staff Rep_Vut_SI (Waste_Resources) Reported Volume Units SI: units in cubic meters of the Reported Volume SI (Rep_Vol_SI). USGS staff An example of this field is "cubic meters". Rsrc_Class (Waste_Resources) Resource Classification: resource classification reported in the source document. USGS staff Indicated Mineral Resources An Indicated Mineral Resource is the part of a Mineral Resource for which quantity, grade or quality, densities, shape and physical characteristics are estimated with sufficient confidence to allow the application of Modifying Factors in sufficient detail to support mine planning and evaluation of the economic viability of the deposit. Geological evidence is derived from adequately detailed and reliable exploration, sampling and testing and is sufficient to assume geological and grade or quality continuity between points of observation. An Indicated Mineral Resource has a lower level of confidence than that applying to a Measured Mineral Resource and may only be converted to a Probable Mineral Reserve. Committee for Mineral Reserves International Reporting Standards (2019) Inferred Mineral Resources An Inferred Mineral Resource is that part of a Mineral Resource for which quantity and grade or quality are estimated on the basis of limited geological evidence and sampling. Geological evidence is sufficient to imply but not verify geological and grade or quality continuity. An Inferred Resource has a lower level of confidence than that applying to an Indicated Mineral Resource and cannot be converted to a Mineral Reserve. It is reasonable to expect that the majority of Inferred Mineral Resources could be upgraded to Indicated Mineral Resources with continued exploration. Committee for Mineral Reserves International Reporting Standards (2019) Probable Mineral Reserves A Probable Mineral Reserve is the economically mineable part of an Indicated, and in some circumstances, a Measured Mineral Resource. The confidence in the Modifying Factors applying to a Probable Mineral Reserve is lower than the applying to a Proved Mineral Reserve. Committee for Mineral Reserves International Reporting Standards (2019) Unclassified Unclassified is only reported when there is a reported Resource Code, but there is no reported Resource Classification. USGS staff Rsrc_Code (Waste_Resources) Resource Code: standard classification system used to classify and report the resource estimate. USGS staff CIM The CIM (Canadian Institute of Mining, Metallurgy and Petroleum) Definition Standards on Mineral Resources and Reserves (CIM Definition Standards) establish definitions and guidance on the definitions for mineral resources, mineral reserves, and mining studies used in Canada. The Mineral Resource, Mineral Reserve, and Mining Study definitions are incorporated, by reference, into National Instrument 43-101 Standards of Disclosure for Mineral Projects (NI 43-101). The CIM Definition Standards can be viewed on the CIM website at www.cim.org. Canadian Institute of Mining, Metallurgy and Petroleum (2014) Unclassified The reported resources are non-compliant with CIM, JORC, or SEC. USGS staff Rsrc_Date (Waste_Resources) Resource Date: year the resource was estimated. USGS staff 1975 2024 year 1 RsrcMethod (Waste_Resources) Resource Method: a brief description of the resource method. USGS staff An example of this field is "Resource defined by 30-RC drill holes". Sec_Cit (Waste_Geology, Waste_Points, Waste_Polygons, Waste_Resources) Secondary Citation(s): shortened version of the secondary citation. Identification includes author name(s) and publication year. USGS staff An example of this field is "(1) Karl (2022); (2) Karl (2023)". Site_ID (Waste_Geology, Waste_Points, Waste_Polygons, Waste_Resources) Site ID: an alpha-numeric identification assigned to a site. USGS staff An example of this field is "NM000001". Site_Name (Waste_Geology, Waste_Points, Waste_Polygons, Waste_Resources) Site Name: name that best represents the grouping of features. USGS staff An example of this field is "Tyrone". State (Waste_Points) State: the 2-letter abbreviation of the U.S. State where the feature is located. The attribution is based on the point location. USGS staff An example of this field is "NM". Superfund (Waste_Points) Superfund: value that indicates if the feature has been declared or proposed as a U.S. Environmental Protection Agency Superfund site. USGS staff An example of this field is "Yes" if the feature is a Superfund site and "No" if the feature has not been a Superfund site. Ton_Factor (Waste_Resources) Tonnage Factor: the tonnage factor is a specific value used based upon density that converts volume of material to a tonnage weight. Associated units are reported in the Tonnage Factor Units (Ton_F_Ut) field. USGS staff 0.0643 1,430 See Ton_F_Ut Ton_F_Ut (Waste_Resources) Tonnage Factor Units: units of the Tonnage Factor (Ton_Factor). USGS staff kilograms per cubic meter A unit of density defined by mass in kilograms divided by cubic meters. USGS staff pounds per cubic food A unit of density defined by mass in pounds divided by volume in cubic feet. USGS staff short tons per cubic foot A unit of density defined by mass in short tons divided by volume in cubic feet. USGS staff units not specified The tonnage factor units were not specified. USGS staff Ton_F_SI (Waste_Resources) Tonnage Factor SI: amount reported in Tonnage Factor (Ton_Factor) converted to International System of Units (SI). Associated units are reported in the Tonnage Factor SI Units (Ton_F_SI_U) field. USGS staff 1.2 1,500 See Ton_F_SI_U Ton_F_SI_U (Waste_Resources) Tonnage Factor SI Units: units of Tonnage Factor SI (Ton_F_SI). USGS staff kilograms per cubic meter A unit of density defined by mass in kilograms divided by cubic meters. USGS staff metric tons per cubic meters A unit of density defined by mass in metric tons divided by volume in cubic meters. Equivalent to grams per cubic centimeter. USGS staff units not specified The tonnage factor units were not specified. USGS staff Topo_Name (Waste_Points) Topo Name: USGS topographic map name provided on the 7.5-minute quadrangle. The attribution is based on the point location. USGS staff An example of this field is "Wind Mountain". The entity and attribute information provide the tabular data associated with the data set. Please review the detailed descriptions that are provided (the individual attribute descriptions) for information on the values that appear as fields/table entries of the dataset. The entity and attribute information are generated by the individual and (or) agency identified as the originator of the dataset. Please review the rest of the metadata record for additional details and information. GS ScienceBase U.S. Geological Survey mailing and physical

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Denver CO 80225 United States of America 1-888-ASK-USGS (1-888-275-8747) sciencebase@usgs.gov https://doi.org/10.5066/P148EEUA 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 Use a file extraction software such as WinZip, 7zip, Peazip https://doi.org/10.5066/P148EEUA none None. 20260123 Nick A Karl U.S. Geological Survey Supervisory Physical Scientist mailing and physical

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Lakewood CO 80225 US 303-236-1222 nkarl@usgs.gov Content Standard for Digital Geospatial Metadata FGDC-STD-001-1998