Lindsey R. King Marie-Noele Croteau Michelle I. Hornberger 20250929 Comma Separated Values (CSV) files https://doi.org/10.5066/P1IHH2D5 Water, bed sediment, and invertebrate tissue were sampled in streams from Butte to near Missoula, Montana, as part of a long-term monitoring program in the upper Clark Fork Basin. The sampling program was completed by the U.S. Geological Survey (USGS), in cooperation with the U.S. Environmental Protection Agency, to characterize aquatic resources in the upper Clark Fork Basin and monitor trace elements associated with historical mining and smelting activities. Sampling sites were on the Clark Fork and a subset of its tributaries. Water samples were collected periodically at 21 sites from October 1, 2021, through September 30, 2022. Bed-sediment and invertebrate tissue samples were collected once at 13 sites in July 2022. Water-quality data included onsite stream properties and laboratory determination of concentrations of major ions, dissolved organic carbon, nitrogen (nitrate plus nitrite), trace elements, and suspended sediment concentrations in stream water samples. Bed-sediment data included trace-element concentrations measured in the fine-grained (finer than 0.063 millimeter) fraction. Biological data included trace-element concentrations in whole-body tissue of selected aquatic benthic invertebrates. The purpose of this data release is to characterize aquatic resources in the upper Clark Fork Basin, with emphasis on trace elements associated with historic mining and smelting activities. 20211001 20220930 Publication Date Complete None Data were collected in the upper Clark Fork Basin, Montana. -114.3347 -112.0000 47.0000 45.7254 None Suspended sediment Benthic invertebrate Bed sediment Trace elements Taxonomy Taxa Division Genus Species USGS Thesaurus Water quality Biota USGS Metadata Identifier USGS:658da2eed34e3265ab14baf3 Common geographic areas United States Montana Clark Fork Integrated Taxonomic System Arctopsyche grandis Claassenia sabulosa Hesperoperla sp. Hydropsyche cockerelli Hydropsyche occidentalis Hydropsyche spp. (Hydropsyche) Smithsonian Institution 2020 Online Reference Washington, D.C. Smithsonian Institution https://itis.gov Michelle I. Hornberger USGS Water Mission Area Earth System Processes Division Research Physical Scientist mailing and physical

PO Box 158

Moffett Field CA 94035 USA 650-329-4467 mhornber@usgs.gov Taxa targeted for sample collection included the orders Trichoptera (caddisflies) and Plecoptera (stoneflies). Samples of each taxon were sorted by genus in the field and to their lowest possible taxonomic level at the USGS Metal Bioavailability Laboratory in Menlo Park, California. All benthic invertebrates were identified to a subgenus level. Kingdom Animalia Subkingdom Bilateria Infrakingdom Protostomia Superphylum Ecdysozoa Phylum Arthropoda Subphylum Hexapoda Class Insecta Subclass Pterygota Infraclass Neoptera Superorder Holometabola Order Trichoptera Superfamily Hydropsychoidea Family Hydropsychidae Subfamily Arctopsychinae Genus Arctopsyche Species Arctopsyche grandis Subfamily Hydropsychinae Genus Ceratopsyche Species Hydropsyche cockerelli Genus Hydropsyche Subgenus Hydropsyche spp. (Hydropsyche) Species Hydropsyche occidentalis Superorder Polyneoptera Order Plecoptera Suborder Systellognatha Family Perlidae Subfamily Perlinae Tribe Perlini Genus Claassenia Species Claassenia sabulosa Subfamily Acroneuriinae Tribe Acroneuriini Genus Hesperoperla sp. None. Please see 'Distribution Info' for details. None. Users are advised to read the dataset's metadata thoroughly to understand appropriate use and data limitations. Lindsey R. King U.S. Geological Survey, Wyoming-Montana Water Science Center Hydrologist mailing and physical

3162 Bozeman Ave

Helena MT 59601 United States of America (406) 465-7021 lrking@usgs.gov This dataset was collected by the U.S. Geological Survey in cooperation with U.S. Environmental Protection Agency. All environmental and laboratory quality assurance and quality control (QA/QC) data were broadly checked for accuracy. Laboratory QC samples and analyses were conducted for water-quality, bed sediment, and biological data to assess variability in the sample processing and preservation methods, analytical method, and cleaning procedures. Supplementary QA/QC tables can be provided upon request for a comprehensive understanding of the instrumentation. Any water-quality result outliers were reviewed and either qualified appropriately or rejected after review and comparison with historical data. No formal logical accuracy tests were conducted, but data were checked for consistency and numerical errors. Dataset is considered complete for the information presented, as described in the abstract. Unfiltered and filtered cadmium results are currently in review and are not ready for publishing. Users are advised to read the rest of the metadata record carefully for additional details. No formal positional accuracy tests were conducted. No formal positional accuracy tests were conducted. Discrete water-quality data collection. Water-quality data consists of onsite stream properties and laboratory determination of chemical and physical constituents in stream water samples. Discrete water-quality samples were collected six to eight times per year at 21 sites, from October 1, 2021, through September 30, 2022, depending on weather conditions. Water samples were collected using a grab, multi-vertical, equal-width-increment, or equal-discharge-increment sampling method using a 1-liter polyethylene bottle with either a DH-81, DH-95, or D-95 depth integrating sampler and composited from vertical transits through the stream depth at multiple locations along the channel cross section as described in Ward and Harr (1990), Horowitz and others (1994), Clark and others (2022), and the USGS National Field Manual (U.S. Geological Survey, 2015). These methods provided flow-weighted (depth and width integrated) composite samples that represented the flow passing through the cross section of the stream. Samples were collected using isokinetic depth-integrated water-quality samplers constructed of plastic or coated with a nonmetallic rubber-containing paint and equipped with polytetrafluoroethylene nozzles. Onsite measurements of pH, specific conductance, and water temperature were measured during water sample collection. Water samples were filtered, preserved, and quality assured according to procedures described in Ward and Harr (1990), Horowitz and others (1994), Clark and others (2022), and the USGS National Field Manual (U.S. Geological Survey, 2015). Ward, J.R., and Harr, C.A. 1990 Publication U.S. Geological Survey Open-File Report Open-File Report 90–140 https://doi.org/10.3133/ofr90140 Horowitz, A.J., Demas, C.R., Fitzgerald, K.K., Miller, T.L., and Rickert, D.A. 1994 Publication U.S. Geological Survey Open-File Report Open-File Report 94–539 https://doi.org/10.3133/ofr94539 Clark, G.D., Hornberger, M.I., Hepler, E.J., and Heinert, T.L. 2022 Publication U.S. Geological Survey Open-File Report Open-File Report 2022–1090 https://doi.org/10.3133/ofr20221090 U.S. Geological Survey 2015 Publication Techniques of water resources investigations Book 9 https://doi.org/10.3133/twri09 Bed sediment data collection. Bed-sediment data consists of trace-element concentrations in the fine-grained (finer than 0.063 millimeter [mm]) fraction of bed-sediment samples. Samples were collected from the surfaces of streambed deposits in areas near the edge of the stream using an acid-rinsed polypropylene scoop. Whenever possible, samples were collected from both sides of the stream. Fine-grained bed-sediment samples were collected using protocols described by Axtmann and Luoma (1991), Shelton and Capel (1994), Hornberger and others (1997), and Clark and others (2022). Individual samples of bed sediment were collected by scooping material from the surface at three to five randomly selected depositional zones located along pools or low-velocity areas. The three to five individual samples were combined to form a single composite sample. This collection process was repeated three times to obtain three composite samples. Each composite sample was wet sieved onsite through a 0.063-mm polyester-mesh sieve using ambient stream water. The fraction of bed sediment in each composite sample that was finer than 0.063 mm was collected in an acid-rinsed 500-milliliter polyethylene bottle and transported to the laboratory on ice. Axtmann, E.V. and Luoma, S.N. 1991 Publication Journal Article Applied Geochemistry, v. 6, no. 1 https://doi.org/10.1016/0883-2927(91)90064-V Shelton, L.R., and Capel, P.D. 1994 Publication U.S. Geological Survey Open-File Report Open-File Report 94–458 https://doi.org/10.3133/ofr94458 Hornberger, M.I., Lambing, J.H., Luoma, S.N., and Axtmann, E.V. 1997 Publication U.S. Geological Survey Open-File Report Open-File Report 97–669 https://doi.org/10.3133/ofr97669 Clark, G.D., Hornberger, M.I., Hepler, E.J., and Heinert, T.L. 2022 Publication U.S. Geological Survey Open-File Report Open-File Report 2022–1090 https://doi.org/10.3133/ofr20221090 Benthic invertebrate tissue data collection. Benthic invertebrate tissue data consists of trace-element concentrations in the whole-body tissue of aquatic benthic invertebrates. Benthic invertebrates of the orders Trichoptera (caddisflies) and Plecoptera (stoneflies) were targeted for collection at all sample locations. Samples were collected following protocols described in Hornberger and others (1997) and Clark and others (2022). Benthic invertebrates at immature stages were collected with a large-nylon-mesh kick net. A single riffle at each site was sampled three times until an adequate number of individual invertebrates were collected to provide enough mass for analysis. In the field, samples were sorted by taxon and placed in acid-rinsed plastic containers with enough ambient stream water to cover, and then were placed on dry ice within 30 minutes of sample collection. At the analyzing laboratory, invertebrate samples were thawed, rinsed with ultrapure deionized water, and then sorted to the lowest possible taxonomic level by the laboratory for analysis of trace element concentrations. Hornberger, M.I., Lambing, J.H., Luoma, S.N., and Axtmann, E.V. 1997 Publication U.S. Geological Survey Open-File Report USGS Open-File Report 97–669 https://doi.org/10.3133/ofr97669 Clark, G.D., Hornberger, M.I., Hepler, E.J., and Heinert, T.L. 2022 Publication U.S. Geological Survey Open-File Report Open-File Report 2022–1090 https://doi.org/10.3133/ofr20221090 Field and laboratory data from each sampling location were reviewed and compared to historical data. Any outliers were either rejected or qualified appropriately. Unfiltered and filtered cadmium results are currently in review and are not ready for publishing. All data were compiled into four comma-separated (CSV) files for this data release. 20231222 FY22_Clark_Fork_Water_Quality_Data.csv The CSV file contains discrete water-quality data collected from 21 sites in the upper Clark Fork Basin from October 1, 2021, to September 30, 2022. Refer to each analyte attribute definition below for measurement units used in the file. Producer Defined Station_ID The USGS unique 8-digit station identification number for the location where data were collected. Producer Defined 12323233 Blacktail Creek above Grove Gulch, at Butte, MT http://doi.org/10.5066/F7P55KJN 12323242 Silver Bow Creek at Montana Street, at Butte, MT http://doi.org/10.5066/F7P55KJN 12323250 Silver Bow Creek below Blacktail Creek, at Butte, MT http://doi.org/10.5066/F7P55KJN 12323600 Silver Bow Creek at Opportunity, MT http://doi.org/10.5066/F7P55KJN 12323670 Mill Creek near Anaconda, MT http://doi.org/10.5066/F7P55KJN 12323700 Mill Creek at Opportunity, MT http://doi.org/10.5066/F7P55KJN 12323710 Willow Creek near Anaconda, MT http://doi.org/10.5066/F7P55KJN 12323720 Willow Creek at Opportunity, MT http://doi.org/10.5066/F7P55KJN 12323750 Silver Bow Creek at Warm Springs, MT http://doi.org/10.5066/F7P55KJN 12323760 Warm Springs Creek near Anaconda, MT http://doi.org/10.5066/F7P55KJN 12323770 Warm Springs Creek at Warm Springs, MT http://doi.org/10.5066/F7P55KJN 12323800 Clark Fork near Galen, MT http://doi.org/10.5066/F7P55KJN 12323840 Lost Creek near Anaconda, MT http://doi.org/10.5066/F7P55KJN 12323850 Lost Creek near Galen, MT http://doi.org/10.5066/F7P55KJN 12324200 Clark Fork at Deer Lodge, MT http://doi.org/10.5066/F7P55KJN 12324400 Clark Fork above Little Blackfoot River near Garrison, MT http://doi.org/10.5066/F7P55KJN 12324680 Clark Fork at Goldcreek, MT http://doi.org/10.5066/F7P55KJN 12331800 Clark Fork near Drummond, MT http://doi.org/10.5066/F7P55KJN 12334550 Clark Fork at Turah Bridge near Bonner, MT http://doi.org/10.5066/F7P55KJN 12340000 Blackfoot River near Bonner, MT http://doi.org/10.5066/F7P55KJN 12340500 Clark Fork above Missoula, MT http://doi.org/10.5066/F7P55KJN Site_Name The USGS site name for the location where data were collected as indicated in the Station_ID attribute column. Producer Defined Site name The USGS site name for the location where data were collected as indicated in the Station_ID attribute column. http://doi.org/10.5066/F7P55KJN Date Date of sample collection formatted as MM/DD/YYYY. Producer Defined 10/12/2021 08/18/2022 Time A numeric identifier for the time the samples were collected formatted as HH:MM. Producer Defined 7:20 18:25 Time_zone Time zone for reported time of sample collection. Producer Defined MDT Mountain Daylight Time Producer Defined Sample_Type Type of sample collected. Producer Defined Environmental Standard water-quality sample. Producer Defined Field Replicate Field replicate sample to assess variability from sample processing and preservation. Producer Defined Laboratory Replicate Laboratory replicate sample to assess variability of the analytical method. Producer Defined Laboratory Spike Laboratory spike sample to assess the extent of matrix interferences and to evaluate bias for specific matrices. Producer Defined Field Blank Field blank sample to address on-site processing of blank water in the same environment in which the samples are collected. Producer Defined Gage_Height Gage height (also known as stage) is the height of the water in the stream above a specific reference point, referenced to either NAVD88, NGVD29, or an arbitrary datum. Gage height refers to the elevation of the water surface in the specific pool at the streamgaging station, not along the entire stream. Gage height also does not refer to the depth of the stream. National Water Information System (https://dx.doi.org/10.5066/F7P55KJN) NA No data associated with the sample. Producer Defined 1.21 6.66 feet, ft Discharge Discharge (also known as streamflow) is the volume of water that passes a given location within a given period of time. Discharge is computed by applying measured gage height readings to a mathematical rating curve. Rating curves are routinely calibrated by U.S. Geological Survey staff with direct measurements of streamflow. National Water Information System (https://dx.doi.org/10.5066/F7P55KJN) NA No data associated with the sample. Producer Defined 0.22 9170 cubic feet per second, cfs Instantaneous_Streamflow Streamflow measured before sample collection. National Water Information System (https://dx.doi.org/10.5066/F7P55KJN) NA No data associated with the sample. Producer Defined 5.19 5.19 cubic feet per second, cfs Temperature_water Water temperature of the stream measured onsite using a multiparameter water-quality monitor. National Water Information System (https://dx.doi.org/10.5066/F7P55KJN) NA No data associated with the sample. Producer Defined 3.0 23.5 degrees Celsius, deg C Specific_Conductance Specific conductance of the stream measured onsite using a multiparameter water-quality monitor. National Water Information System (https://dx.doi.org/10.5066/F7P55KJN) 1 1924 microsiemens per centimeter at 25 degrees Celsius, µS/cm pH pH of the stream measured onsite using a multiparameter water-quality monitor. National Water Information System (https://dx.doi.org/10.5066/F7P55KJN) NA No data associated with the sample. Producer Defined 4.8 9.0 Standard units Nitrate_plus_nitrite Laboratory result for filtered nitrate plus nitrite. National Water Information System (https://dx.doi.org/10.5066/F7P55KJN) NA No data associated with the sample. Producer Defined 0.18 1.61 milligrams per liter as nitrogen, mg/L as N RC_Organic_Carbon Remark code for attribute labeled Organic_Carbon. Producer Defined NA No data associated with the sample. Producer Defined < Actual value is known to be less than the value shown. Producer Defined Organic_Carbon Laboratory result for filtered organic carbon. Refer to prior attribute for associated remark code. National Water Information System (https://dx.doi.org/10.5066/F7P55KJN) NA No data associated with the sample. Producer Defined 0.23 8.21 milligrams per liter, mg/L RC_Calcium_wf Remark code for attribute labeled Calcium_wf. Producer Defined NA No data associated with the sample. Producer Defined < Actual value is known to be less than the value shown. Producer Defined Calcium_wf Laboratory result for filtered calcium. Refer to prior attribute for associated remark code. National Water Information System (https://dx.doi.org/10.5066/F7P55KJN) NA No data associated with the sample. Producer Defined 0.02 394 milligrams per liter, mg/L Calcium_wu Laboratory result for unfiltered calcium. National Water Information System (https://dx.doi.org/10.5066/F7P55KJN) NA No data associated with the sample. Producer Defined 30.8 401 milligrams per liter, mg/L RC_Magnesium_wf Remark code for attribute labeled Magnesium_wf. Producer Defined NA No data associated with the sample. Producer Defined < Actual value is known to be less than the value shown Producer Defined Magnesium_wf Laboratory result for filtered magnesium. Refer to prior attribute for associated remark code. National Water Information System (https://dx.doi.org/10.5066/F7P55KJN) NA No data associated with the sample. Producer Defined 0.01 29.7 milligrams per liter, mg/L Magnesium_wu Laboratory result for unfiltered magnesium. National Water Information System (https://dx.doi.org/10.5066/F7P55KJN) NA No data associated with the sample. Producer Defined 7.11 15.1 milligrams per liter, mg/L RC_Sodium_wf Remark code for attribute labeled Sodium_wf. Producer Defined NA No data associated with the sample. Producer Defined < Actual value is known to be less than the value shown. Producer Defined Sodium_wf Laboratory result for filtered sodium. Refer to prior attribute for associated remark code. National Water Information System (https://dx.doi.org/10.5066/F7P55KJN) NA No data associated with the sample. Producer Defined 0.40 50.1 milligrams per liter, mg/L RC_Potassium_wf Remark code for attribute labeled Potassium_wf. Producer Defined NA No data associated with the sample. Producer Defined < Actual value is known to be less than the value shown. Producer Defined Potassium_wf Laboratory result for filtered potassium. Refer to prior attribute for associated remark code. National Water Information System (https://dx.doi.org/10.5066/F7P55KJN) NA No data associated with the sample. Producer Defined 0.30 14.4 milligrams per liter, mg/L Chloride_wf Laboratory result for filtered chloride. National Water Information System (https://dx.doi.org/10.5066/F7P55KJN) NA No data associated with the sample. Producer Defined 0.04 50.4 milligrams per liter, mg/L RC_Sulfate_wf Remark code for attribute labeled Sulfate_wf. Producer Defined NA No data associated with the sample. Producer Defined < Actual value is known to be less than the value shown. Producer Defined Sulfate_wf Laboratory result for filtered sulfate. Refer to prior attribute for associated remark code. National Water Information System (https://dx.doi.org/10.5066/F7P55KJN) NA No data associated with the sample. Producer Defined 0.02 957 milligrams per liter, mg/L RC_Fluoride_wf Remark code for attribute labeled Fluoride_wf. Producer Defined NA No data associated with the sample. Producer Defined < Actual value is known to be less than the value shown. Producer Defined Fluoride_wf Laboratory result for filtered fluoride. Refer to prior attribute for associated remark code. National Water Information System (https://dx.doi.org/10.5066/F7P55KJN) NA No data associated with the sample. Producer Defined 0.01 1.35 milligrams per liter, mg/L RC_Silica_wf Remark code for attribute labeled Silica_wf. Producer Defined NA No data associated with the sample. Producer Defined < Actual value is known to be less than the value shown. Producer Defined Silica_wf Laboratory result for filtered silica. Refer to prior attribute for associated remark code. National Water Information System (https://dx.doi.org/10.5066/F7P55KJN) NA No data associated with the sample. Producer Defined 0.05 26.7 milligrams per liter, mg/L RC_Arsenic_wf Remark code for attribute labeled Arsenic_wf. Producer Defined NA No data associated with the sample. Producer Defined < Actual value is known to be less than the value shown. Producer Defined Arsenic_wf Laboratory result for filtered arsenic. Refer to prior attribute for associated remark code. National Water Information System (https://dx.doi.org/10.5066/F7P55KJN) NA No data associated with the sample. Producer Defined 0.10 76.0 micrograms per liter, µg/L RC_Arsenic_wu Remark code for attribute labeled Arsenic_wu. Producer Defined NA No data associated with the sample. Producer Defined < Actual value is known to be less than the value shown. Producer Defined Arsenic_wu Laboratory results for unfiltered arsenic. Refer to prior attribute for associated remark code. National Water Information System (https://dx.doi.org/10.5066/F7P55KJN) NA No data associated with the sample. Producer Defined 0.10 84.4 micrograms per liter, µg/L RC_Copper_wf Remark code for attribute labeled Copper_wf. Producer Defined NA No data associated with the sample. Producer Defined < Actual value is known to be less than the value shown. Producer Defined Copper_wf Laboratory results for filtered copper. Refer to prior attribute for associated remark code. National Water Information System (https://dx.doi.org/10.5066/F7P55KJN) NA No data associated with the sample. Producer Defined 0.40 9.52 micrograms per liter, µg/L RC_Copper_wu Remark code for attribute labeled Copper_wu. Producer Defined NA No data associated with the sample. Producer Defined < Actual value is known to be less than the value shown. Producer Defined Copper_wu Laboratory result for unfiltered copper. Refer to prior attribute for associated remark code. National Water Information System (https://dx.doi.org/10.5066/F7P55KJN) NA No data associated with the sample. Producer Defined 0.40 98.9 micrograms per liter, µg/L RC_Iron_wu Remark code for attribute labeled Iron_wu. Producer Defined NA No data associated with the sample. Producer Defined < Actual value is known to be less than the value shown. Producer Defined Iron_wu Laboratory results for unfiltered iron. Refer to prior attribute for associated remark code. National Water Information System (https://dx.doi.org/10.5066/F7P55KJN) NA No data associated with the sample. Producer Defined 5.0 1867 micrograms per liter, µg/L RC_Iron_wf Remark code for attribute labeled Iron_wf. Producer Defined NA No data associated with the sample. Producer Defined < Actual value is known to be less than the value shown. Producer Defined Iron_wf Laboratory result for filtered iron. Refer to prior attribute for associated remark code. National Water Information System (https://dx.doi.org/10.5066/F7P55KJN) NA No data associated with the sample. Producer Defined 5.0 214 micrograms per liter, µg/L RC_Lead_wf Remark code for attribute labeled Lead_wf. Producer Defined NA No data associated with the sample. Producer Defined < Actual value is known to be less than the value shown. Producer Defined Lead_wf Laboratory result for filtered lead. Refer to prior attribute for associated qualifier. National Water Information System (https://dx.doi.org/10.5066/F7P55KJN) NA No data associated with the sample. Producer Defined 0.02 0.95 micrograms per liter, µg/L RC_Lead_wu Remark code for attribute labeled Lead_wu. Producer Defined NA No data associated with the sample. Producer Defined < Actual value is known to be less than the value shown. Producer Defined Lead_wu Laboratory result for unfiltered lead. Refer to prior attribute for associated remark code. National Water Information System (https://dx.doi.org/10.5066/F7P55KJN) NA No data associated with the sample. Producer Defined 0.06 12.7 micrograms per liter, µg/L RC_Manganese_wu Remark code for attribute labeled Manganese_wu. Producer Defined NA No data associated with the sample. Producer Defined < Actual value is known to be less than the value shown. Producer Defined Manganese_wu Laboratory result for unfiltered manganese. Refer to prior attribute for associated remark code. National Water Information System (https://dx.doi.org/10.5066/F7P55KJN) NA No data associated with the sample. Producer Defined 0.40 448 micrograms per liter, µg/L RC_Manganese_wf Remark code for attribute labeled Manganese_wf. Producer Defined NA No data associated with the sample. Producer Defined < Actual value is known to be less than the value shown. Producer Defined Manganese_wf Laboratory result for filtered manganese. Refer to prior attribute for associated remark code. National Water Information System (https://dx.doi.org/10.5066/F7P55KJN) NA No data associated with the sample. Producer Defined 0.40 293 micrograms per liter, µg/L RC_Zinc_wf Remark code for attribute labeled Zinc_wf. Producer Defined NA No data associated with the sample. Producer Defined < Actual value is known to be less than the value shown. Producer Defined Zinc_wf Laboratory result for filtered zinc. Refer to prior attribute for associated remark code. National Water Information System (https://dx.doi.org/10.5066/F7P55KJN) NA No data associated with the sample. Producer Defined 2.0 74.4 micrograms per liter, µg/L RC_Zinc_wu Remark code for attribute labeled Zinc_wu. Producer Defined NA No data associated with the sample. Producer Defined < Actual value is known to be less than the value shown. Producer Defined Zinc_wu Laboratory result for unfiltered zinc. Refer to prior attribute for associated remark code. National Water Information System (https://dx.doi.org/10.5066/F7P55KJN) NA No data associated with the sample. Producer Defined 2.0 113 micrograms per liter, µg/L RC_Alkalinity_lab Remark code for attribute labeled Alkalinity_lab. Not Specified NA No data associated with the sample. Producer Defined < Actual value is known to be less than the value shown. Producer Defined Alkalinity_lab Laboratory result for filtered alkalinity. Refer to prior attribute for associated remark code. National Water Information System (https://dx.doi.org/10.5066/F7P55KJN) NA No data associated with the sample. Producer Defined 2.5 170 milligrams per liter as calcium carbonate, mg/L as CaCO3 RC_Turbidity_lab Remark code for attribute labeled Turbidity_lab. Producer Defined NA No data associated with the sample. Producer Defined < Actual value is known to be less than the value shown. Producer Defined E Indicates concentrations were estimated. Producer Defined Turbidity_lab Laboratory result for unfiltered turbidity. Refer to prior attribute for associated remark code. National Water Information System (https://dx.doi.org/10.5066/F7P55KJN) NA No data associated with the sample. Producer Defined 2.0 6.57 nephelometric turbidity ratio unit, NTRU Suspended_Sediment_percent_finer_than_0.0625_mm Laboratory result for suspended sediment (finer than 0.0625 millimeter). National Water Information System (https://dx.doi.org/10.5066/F7P55KJN) NA No data associated with the sample. Producer Defined 37 99 percent finer than 0.0625-millimeter RC_Suspended_Sediment_Concentration Remark code for attribute labeled Suspended_Sediment_Concentration. Producer Defined NA No data associated with the sample. Producer Defined < Actual value is known to be less than the value shown. Producer Defined Suspended_Sediment_Concentration Laboratory result for suspended sediment concentration. Refer to prior attribute for associated remark code. National Water Information System (https://dx.doi.org/10.5066/F7P55KJN) NA No data associated with the sample. Producer Defined 0.5 111 milligrams per liter, mg/L FY22_Clark_Fork_Bed_Sediment_Data.csv The CSV file contains laboratory bed sediment sample results from 13 sites in the upper Clark Fork Basin. Concentrations presented in the spreadsheet are in units of micrograms per grams (µg/g) and were determined for the fine-grained fraction (material finer than 0.063 millimeter in diameter). Producer Defined Station_ID The USGS unique 8- to 15- digit station identification number for the location where data were collected. Producer Defined 12323600 Silver Bow Creek at Opportunity, MT http://doi.org/10.5066/F7P55KJN 12323750 Silver Bow Creek at Warm Springs, MT http://doi.org/10.5066/F7P55KJN 12323800 Clark Fork near Galen, MT http://doi.org/10.5066/F7P55KJN 461415112450801 Clark Fork below Lost Creek, near Galen, MT http://doi.org/10.5066/F7P55KJN 461559112443301 Clark Fork at County Bridge near Racetrack, MT http://doi.org/10.5066/F7P55KJN 461903112440701 Clark Fork at Dempsey Creek diversion near Racetrack, MT http://doi.org/10.5066/F7P55KJN 12324200 Clark Fork at Deer Lodge, MT http://doi.org/10.5066/F7P55KJN 12324400 Clark Fork above Little Blackfoot River near Garrison, MT http://doi.org/10.5066/F7P55KJN 12324680 Clark Fork at Goldcreek, MT http://doi.org/10.5066/F7P55KJN 12331800 Clark Fork near Drummond, MT http://doi.org/10.5066/F7P55KJN 12340000 Blackfoot River near Bonner, MT http://doi.org/10.5066/F7P55KJN 12334550 Clark Fork at Turah Bridge near Bonner, MT http://doi.org/10.5066/F7P55KJN 12340500 Clark Fork above Missoula, MT http://doi.org/10.5066/F7P55KJN Site_Name The USGS site name for the location where data were collected as indicated in the Station_ID column. Producer Defined Site name The USGS site name for the location where data were collected as indicated in the Station_ID column. http://doi.org/10.5066/F7P55KJN Sample_Collection_Month Month of bed sediment sample collection. Producer Defined July Month of bed sediment sample collection. Producer Defined Sample_Collection_Year Year of bed sediment sample collection. Producer Defined 2022 Year of bed sediment sample collection. Producer Defined Sample_Type Type of sample analyzed. Producer Defined Regular Standard bed-sediment sample. Producer Defined Duplicate Duplicate bed-sediment sample. Producer Defined Matrix Matrix of sample analyzed. Producer Defined Sediment Bed sediment samples were analyzed in the fine-grained fraction (finer than 0.063 millimeter) sediment for trace-element concentration. Producer defined Arsenic Arsenic concentration of bed sediment sample. Producer defined 7.08 154 micrograms per gram, µg/g RC_Cadmium Remark code for attribute labeled Cadmium. Producer Defined NA No data associated with the sample. Producer Defined < Actual value is known to be less than the value shown. Producer Defined Cadmium Cadmium concentration of bed sediment sample. Refer to prior attribute for associated remark code. Producer Defined 0.07 10.2 micrograms per gram, µg/g Chromium Chromium concentration of bed sediment sample. Producer Defined 19.4 41.3 micrograms per gram, µg/g Copper Copper concentration of bed sediment sample. Producer Defined 23.8 1353 micrograms per gram, µg/g Iron Iron concentration of bed sediment sample. Producer Defined 18818 43058 micrograms per gram, µg/g Manganese Manganese concentration of bed sediment sample. Producer Defined 374 5775 micrograms per gram, µg/g Nickel Nickel concentration of bed sediment sample. Producer Defined 11.4 24.6 micrograms per gram, µg/g Lead Lead concentration of bed sediment sample. Producer Defined 26.0 195 micrograms per gram, µg/g Zinc Zinc concentration of bed sediment sample. Producer Defined 59.3 2274 micrograms per gram, µg/g FY22_Clark_Fork_Biota_Data.csv The CSV file contains laboratory analytical results for whole-body benthic invertebrate samples collected from 13 sites in the upper Clark Fork Basin. All benthic invertebrate sample concentrations are reported in units of micrograms per gram (µg/g). Producer Defined Station_ID The USGS unique 8- to 15- digit station identification number for the location where data were collected. Producer Defined 12323600 Silver Bow Creek at Opportunity, MT http://doi.org/10.5066/F7P55KJN 12323750 Silver Bow Creek at Warm Springs, MT http://doi.org/10.5066/F7P55KJN 12323800 Clark Fork near Galen, MT http://doi.org/10.5066/F7P55KJN 461415112450801 Clark Fork below Lost Creek near Galen, MT http://doi.org/10.5066/F7P55KJN 461559112443301 Clark Fork at County Bridge near Racetrack, MT http://doi.org/10.5066/F7P55KJN 461903112440701 Clark Fork at Dempsey Creek diversion near Racetrack, MT http://doi.org/10.5066/F7P55KJN 12324200 Clark Fork at Deer Lodge, MT http://doi.org/10.5066/F7P55KJN 12324400 Clark Fork above Little Blackfoot River near Garrison, MT http://doi.org/10.5066/F7P55KJN 12324680 Clark Fork at Goldcreek, MT http://doi.org/10.5066/F7P55KJN 12331800 Clark Fork near Drummond, MT http://doi.org/10.5066/F7P55KJN 12340000 Blackfoot River near Bonner, MT http://doi.org/10.5066/F7P55KJN 12334550 Clark Fork at Turah Bridge near Bonner, MT http://doi.org/10.5066/F7P55KJN 12340500 Clark Fork above Missoula, MT http://doi.org/10.5066/F7P55KJN Site_Name The USGS site name for the location where data were collected as indicated in the Station_ID column. Producer Defined Site name The USGS site name for the location where data were collected as indicated in the Station_ID column. http://doi.org/10.5066/F7P55KJN Sample_Collection_Month Month of benthic invertebrate sample collection. Producer Defined July Month of benthic invertebrate sample collection. Producer Defined Sample_Collection_Year Year of benthic invertebrate sample collection. Producer Defined 2022 Year of benthic invertebrate sample collection. Producer Defined Sample_Type Type of sample analyzed. Producer Defined Regular Standard biota sample. Producer Defined Matrix Matrix of sample analyzed. Producer Defined Biota Whole-body tissue of aquatic benthic invertebrates. Producer defined Taxa Taxa of benthic invertebrate sample analyzed by laboratory. Producer Defined Arctopsyche grandis Species of caddisfly. Producer defined Claassenia sabulosa Species of stonefly. Producer defined Hesperoperla sp. Genus of stonefly. Producer defined Hydropsyche cockerelli Species of caddisfly. Producer defined Hydropsyche occidentalis Species of caddisfly. Producer defined Hydropsyche spp. (Hydropsyche) Genus of caddisfly with possible multiple species. Producer defined Arsenic Arsenic concentration of whole-body benthic invertebrate sample. Producer Defined 1.24 19.6 micrograms per gram, µg/g RC_Cadmium Remark code for attribute labeled Cadmium. Producer Defined NA No data associated with the sample. Producer Defined < Actual value is known to be less than the value shown. Producer Defined Cadmium Cadmium concentration of whole-body benthic invertebrate sample. Refer to prior attribute for associated remark code. Producer Defined 0.13 3.99 micrograms per gram, µg/g RC_Flag_Cadmium Remark code for flag given to cadmium concentration result. Producer Defined NA No data associated with the sample. Producer Defined < Actual value is known to be less than the value shown. Producer Defined Flag_Cadmium Flag given to cadmium concentration result. Refer to prior attribute for associated remark code. Producer Defined NA No data associated with the sample. Producer Defined RL Reporting level Producer Defined RC_Chromium Remark code for attribute labeled Chromium. Producer Defined NA No data associated with the sample. Producer Defined < Actual value is known to be less than the value shown. Producer Defined Chromium Chromium concentration of whole-body benthic invertebrate sample. Refer to prior attribute for associated remark code. Producer Defined 0.35 3.56 micrograms per gram, µg/g RC_Flag_Chromium Remark code for flag given to chromium concentration result. Producer Defined NA No data associated with the sample. Producer Defined < Actual value is known to be less than the value shown. Producer Defined Flag_Chromium Flag given to chromium concentration result. Refer to prior attribute for associated remark code. Producer Defined NA No data associated with the sample. Producer Defined RL Reporting level Producer Defined Copper Copper concentration of whole-body benthic invertebrate sample. Producer Defined 15.3 180 micrograms per gram, µg/g Iron Iron concentration of whole-body benthic invertebrate sample. Producer Defined 84.3 2444 micrograms per gram, µg/g Manganese Manganese concentration of whole-body benthic invertebrate sample. Producer Defined 31.2 1727 micrograms per gram, µg/g Nickel Nickel concentration of whole-body benthic invertebrate sample. Producer Defined 0.07 2.80 micrograms per gram, µg/g RC_Lead Remark code for attribute labeled Lead. Producer Defined NA No data associated with the sample. Producer Defined < Actual value is known to be less than the value shown. Producer Defined Lead Lead concentration of whole-body benthic invertebrate sample. Refer to prior attribute for associated qualifier. Producer Defined 0.07 46.5 micrograms per gram, µg/g RC_Flag_Lead Remark code for flag given to lead concentration result. Producer Defined NA No data associated with the sample. Producer Defined < Actual value is known to be less than the value shown. Producer Defined Flag_Lead Flag given to lead concentration result. Refer to prior attribute for associated remark code. Producer Defined NA No data associated with the sample. Producer Defined RL Reporting level Producer Defined Zinc Zinc concentration of whole-body benthic invertebrate sample. Producer Defined 110 640 micrograms per gram, µg/g FY22_Clark_Fork_QAQC_Data.csv This CSV file contains laboratory quality assurance and quality control results for bed sediment and whole-body benthic invertebrate sample analyses. Producer defined Sample_type Type of sample analyzed at the laboratory. Producer Defined Type of sample analyzed at the laboratory. Reference_Material Type of reference material analyzed by the laboratory. Producer Defined NA No data associated with the sample. Producer Defined Type of reference material analyzed by the laboratory. QAQC_Matrix Matrix of sample analyzed. Producer Defined CRM Certified reference material. Producer defined DUP Analytical duplicate. Producer defined eQC External check standard solution. Producer defined iQC Internally prepared check standard. Producer defined MDL Method detection limit. Producer defined pblank Procedural blank. Producer defined Analyte Analyte measured by laboratory. Producer Defined As Arsenic Producer defined Cd Cadmium Producer defined Cr Chromium Producer defined Cu Copper Producer defined Fe Iron Producer defined Mn Manganese Producer defined Ni Nickel Producer defined Pb Lead Producer defined Zn Zinc Producer defined Result_mgl Laboratory result for corresponding analyte. Producer Defined NA No data associated with the sample. Producer Defined 0.001 101 milligrams per liter, mg/L Flag_Result_mgl Flag given to laboratory result. Producer Defined NA No data associated with the sample. Producer Defined Less than method detection limit Indicates concentrations were less than the method detection limit. Producer Defined RC_Result_ugg Remark code given to laboratory result. Producer Defined NA No data associated with the sample. Producer Defined < Actual value is known to be less than the value shown. Producer Defined Result_ugg Laboratory result for corresponding analyte. Producer Defined NA No data associated with the sample. Producer Defined 0.001 32675 micrograms per gram, µg/g Percent_Recovery Analyzing laboratory percent recovery = 100 x [(spiked sample concentration - unspiked sample concentration)/effective spike concentration]. Producer Defined NA No data associated with the sample. Producer Defined 51.8 311 percent, % Flag_Percent_Recovery Flag given to laboratory percent recovery. Producer Defined NA No data associated with the sample. Producer Defined Less than method detection limit Indicates concentrations were less than the method detection limit. Producer Defined Less than reporting level Actual value is known to be less than the value shown. Producer Defined GS ScienceBase U.S. Geological Survey mailing and physical

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. This information may be updated without notification. The USGS shall not be liable for any activity involving these data, installation, firmness of the data for a particular purpose, its use, or analysis. Digital Data https://doi.org/10.5066/P1IHH2D5 None 20250929 Lindsey R. King U.S. Geological Survey, Wyoming-Montana Water Science Center mailing and physical

3162 Bozeman Ave

Helena MT 59601 (406) 465-7021 lrking@usgs.gov FGDC Biological Data Profile of the Content Standard for Digital Geospatial Metadata FGDC-STD-001.1-1999