The National Hydrography Dataset (NHD) High Resolution flowlines were used as a base to provide additional information on the connectivity of the stream network for the hydrographic basins in and around Montana. In addition to the attributes that are published as part of the NHD data, two fields were added to the attribute table to associate streams that do not have a Geographic Names Information System (GNIS) name with the GNIS name and NHD reachcode of the nearest downstream named flowline. The National Hydrography Dataset (NHD) is a feature-based database that interconnects and uniquely identifies the stream segments or reaches that make up the nation's surface water drainage system. NHD data were originally developed at 1:100,000-scale and exists at that scale for the whole country. This high-resolution NHD, generally developed at 1:24,000/1:12,000 scale, adds detail to the original 1:100,000-scale NHD. Local resolution NHD is being developed where partners and data exist. The NHD contains reach codes for networked features, flow direction, names, and centerline representations for areal water bodies. The NHD also incorporates the National Spatial Data Infrastructure framework criteria established by the Federal Geographic Data Committee. This dataset is NHD Model version 2.2.1. For more information on the NHD High Resolution dataset, see Model Diagram at: http://ftp.geoinfo.msl.mt.gov/Data/Spatial/MSDI/Hydrography.

The U.S. Geological Survey (USGS), in cooperation with the Wyoming Water Development Office, developed streamflow statistics for active (through September 30, 2021) and discontinued USGS streamgages in and near Wyoming with 10 or more years of daily mean streamflow record. The computation of streamflow statistics for USGS streamgages is part of a larger study to develop a StreamStats application (www.usgs.gov/streamstats) for the State of Wyoming (https://www.usgs.gov/centers/wyoming-montana-water-science-center/science/wyoming-streamstats). StreamStats is a web-based computer program that can be used to delineate drainage areas, determine basin characteristics, and compute streamflow statistics at locations with and without streamgages (https://streamstats.usgs.gov/ss/; Ries and others, 2024). Streamflow at each streamgage was assessed for degree of human alteration owing to dams and diversions before streamflow statistics were computed. Streamflow records from 631 streamgage periods of record were used to compute basic, seasonal, and flow-duration statistics; records for 390 streamgage periods of record were used to compute n-day statistics and statistics that can be used for regional regression. Methods used to compute the summary statistics contained in this data release are described in an accompanying report (Armstrong and others, 2025).

The U.S. Geological Survey (USGS), in cooperation with the Wyoming Water Development Office, developed streamflow statistics for active (through September 30, 2021) and discontinued USGS streamgages in and near Wyoming with 10 or more years of daily mean streamflow record. The computation of streamflow statistics for USGS streamgages is part of a larger study to develop a StreamStats application (www.usgs.gov/streamstats) for the State of Wyoming (https://www.usgs.gov/centers/wyoming-montana-water-science-center/science/wyoming-streamstats). StreamStats is a web-based computer program that can be used to delineate drainage areas, determine basin characteristics, and compute streamflow statistics at locations with and without streamgages (https://streamstats.usgs.gov/ss/; Ries and others, 2024). Streamflow at each streamgage was assessed for degree of human alteration owing to dams and diversions before streamflow statistics were computed. Streamflow records from 631 streamgage periods of record were used to compute basic, seasonal, and flow-duration statistics; records for 390 streamgage periods of record were used to compute n-day statistics and statistics that can be used for regional regression. Methods used to compute the summary statistics contained in this data release are described in an accompanying report (Armstrong and others, 2025).

This child item includes daily mean streamflow data obtained from the U.S. Geological Survey (USGS) National Water Information System database (https://doi.org/10.5066/F7P55KJN) and subsequently used in the computation of streamflow statistics. Daily mean streamflow data for some streamgages were removed from the analyses if the daily streamflows were determined to be incorrect, estimated, or had other problems. Streamflow at each streamgage was assessed for degree of human alteration owing to dams and diversions before streamflow statistics were computed. Methods used to remove daily mean streamflows, assess alteration, and compute the summary statistics contained in this data release are described in an accompanying report (Armstrong and others, 2025). Daily mean streamflow data for the period of record at each USGS streamgage used in the analyses are grouped into 15 folders organized by the 4-digit hydrologic unit code (HUC; https://water.usgs.gov/GIS/huc.html) in which the streamgage is located. The content of these folders is described in this metadata file. A table describing characteristics of the streamgages used in the analyses is provided in text file "AtSite_Table1_StreamgageSummary.txt."

The U.S. Geological Survey (USGS), in cooperation with the Wyoming Water Development Office, developed streamflow statistics for active (through September 30, 2021) and discontinued USGS streamgages in and near Wyoming with 10 or more years of daily mean streamflow record. The computation of streamflow statistics for USGS streamgages is part of a larger study to develop a StreamStats application (www.usgs.gov/streamstats) for the State of Wyoming (https://www.usgs.gov/centers/wyoming-montana-water-science-center/science/wyoming-streamstats). StreamStats is a web-based computer program that can be used to delineate drainage areas, determine basin characteristics, and compute streamflow statistics at locations with and without streamgages (https://streamstats.usgs.gov/ss/; Ries and others, 2024). Streamflow at each streamgage was assessed for degree of human alteration owing to dams and diversions before streamflow statistics were computed. Streamflow records from 631 streamgage periods of record were used to compute basic, seasonal, and flow-duration statistics; records for 390 streamgage periods of record were used to compute n-day statistics and statistics that can be used for regional regression. Methods used to compute the summary statistics contained in this data release are described in an accompanying report (Armstrong and others, 2025).

This data release presents two datasets including waterbodies (reservoirs, lakes, ponds, wetlands, etc.) and flowlines (stream reaches) from the high-resolution National Hydrography Dataset Plus (NHDPlus HR) that are potentially observable from Landsat images for the United States (excluding Alaska). To determine where National Hydrography Dataset Plus high resolution (NHDPlus HR; USGS 2019) features intersect locations with observed water, a workflow was developed using the Global Surface Water Extent dataset (GSWE; Pekel et al. 2016) to specify where water was observed by Landsat from 1984 to 2019. The workflow determines where the extent of NHDPlus HR water features (waterbodies and areas) overlaps the maximum extent of Landsat-observed water (as defined by GSWE), then removes edge pixels to determine if any pure water pixels are observable by Landsat within a water feature’s extent. Each pure-water pixel within NHDPlus HR area features (i.e. rivers represented by polygons) was associated with the nearest NHDPlus HR flowline. The result identifies flowlines and waterbodies (as defined by NHDPlus HR) that contain at least one estimated pure-water pixel from the GSWE and are thus ‘potentially resolvable’. The resulting datasets can be linked to the NHDWaterbodies and NHDFlowline layers of NHDPlus HR to identify waterbodies where remote sensing may be a suitable monitoring method.

This dataset was produced by the U.S. Geological Survey (USGS) in cooperation with the Wyoming Water Development Office for the purpose of delineating drainage basins and performing hydrologic analysis in the Wyoming StreamStats application. The data are raster representations of the fundamental dataset layers necessary for the functionality of StreamStats application within the Wyoming StreamStats study area. The StreamStats application provides access to spatial analytical tools that are useful for water-resources planning and management, and for engineering and design purposes. The map-based user interface can be used to delineate drainage areas, calculate basin characteristics, and estimates of flow statistics, and more. The study boundary for data in this data release is defined by the extent of all HUC08 watersheds flowing in or out of the state of Wyoming.

This dataset was produced by the U.S. Geological Survey (USGS) in cooperation with the Wyoming Water Development Office for the purpose of delineating drainage basins and performing hydrologic analysis in the Wyoming StreamStats application. The data are raster representations of the fundamental dataset layers necessary for the functionality of StreamStats application within the Wyoming StreamStats study area. The StreamStats application provides access to spatial analytical tools that are useful for water-resources planning and management, and for engineering and design purposes. The map-based user interface can be used to delineate drainage areas, calculate basin characteristics, and estimates of flow statistics, and more. The study boundary for data in this data release is defined by the extent of all HUC08 watersheds flowing in or out of the state of Wyoming.