This U.S. Geological Survey (USGS) data release is an assessment of aquatic habitat within the tributaries of the lower Middle Fork Salmon River. These datasets are primarily focused on physical stream habitat (2020-21 stream temperature data) and the presence or absence (2021 eDNA data) of fish that inhabit the basin. Many environmental stressors contribute to the declining range and density of Bull trout (S. confluentus) populations, one of which is the toxic trace metals contributions from legacy mine waste and adits. These data were collected in stream habitats with variable physical and thermal conditions. Characterizing and comparing reference streams of similar physical attributes will assist to differentiate the regional impacts of toxic trace metals exposure.

This USGS data release evaluates the impact of historical mining sites on water quality using samples collected in late July 2021 from Big Creek tributaries Coin Creek, Smith Creek, and Monumental Creek in Valley County, Idaho. These data were collected to support a fisheries mining impact assessment in the Middle Fork Salmon River. Specific conductance, pH, and stream temperature were measured in the field. Analyses include major cations and anions, alkalinity, trace metals, total mercury, and methylmercury.

This USGS data release evaluates the impact of historical mining sites on water quality using samples collected in late July 2021 from Big Creek tributaries Coin Creek, Smith Creek, and Monumental Creek in Valley County, Idaho. These data were collected to support a fisheries mining impact assessment in the Middle Fork Salmon River. Specific conductance, pH, and stream temperature were measured in the field. Analyses include major cations and anions, alkalinity, trace metals, total mercury, and methylmercury.

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 Data Release provides stream temperature data (13 sites) and fish community data (3 sites) in Big Hunting Creek, Maryland. Data were collected during summer baseflow conditions in 2023. This product supports brook trout conservation and restoration research needs identified by Maryland Department of Natural Resources. We collected temperature data with Onset ProV2 water temperature gages in slotted PVC housings mounted to the stream substrates with rebar. Gages recorded temperature every 15 minutes from July 11, 2023 (midnight) until July 15, 2023 (midnight) (337 observations per site). We collected fish community data following Maryland Department of Natural Resources protocols (Maryland Biological Stream Survey) with 2-pass backpack electrofishing and dipnets. All fishes were identified to species and released. Sites include locations upstream and downstream of an impoundment (Frank Bentz Pond) in Big Hunting Creek.

This Data Release provides stream temperature data (13 sites) and fish community data (3 sites) in Big Hunting Creek, Maryland. Data were collected during summer baseflow conditions in 2023. This product supports brook trout conservation and restoration research needs identified by Maryland Department of Natural Resources. We collected temperature data with Onset ProV2 water temperature gages in slotted PVC housings mounted to the stream substrates with rebar. Gages recorded temperature every 15 minutes from July 11, 2023 (midnight) until July 15, 2023 (midnight) (337 observations per site). We collected fish community data following Maryland Department of Natural Resources protocols (Maryland Biological Stream Survey) with 2-pass backpack electrofishing and dipnets. All fishes were identified to species and released. Sites include locations upstream and downstream of an impoundment (Frank Bentz Pond) in Big Hunting Creek.

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."

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).