WATER-QUALITY, BED-SEDIMENT, AND BIOLOGICAL 

DATA (OCTOBER 1993 THROUGH SEPTEMBER 1994) 

AND STATISTICAL SUMMARIES OF DATA FOR 

STREAMS IN THE UPPER CLARK FORK BASIN, 

MONTANA

By John H. Lambing, Michelle I. Hornberger, Ellen V. Axtmann, and Kent A. Dodge

U.S. GEOLOGICAL SURVEY

Open-File Report 95-429

Prepared in cooperation with the

U.S. ENVIRONMENTAL PROTECTION AGENCY

Helena, Montana 

September 1995
U.S. DEPARTMENT OF THE INTERIOR 

BRUCE BABBITT, Secretary

U.S. GEOLOGICAL SURVEY 

Gordon P. Eaton, Director

For additional information write to: Copies of this report may be purchased from:

District Chief U.S. Geological Survey

U.S. Geological Survey Earth Science Information Center

428 Federal Building Open-File Reports Section

Drawer 10076 Box 25286, Mail Stop 517

301 South Park Denver Federal Center

Helena, MT 59626-0076 Denver, CO 80225
CONTENTS

Page

Abstract.................................................................................................................................................................................. 1

Introduction................................................................................._^ 1

Sampling locations and types of data.................................................................................................................................... 2

Water-quality data.................................................................................................................................................................. 3

Methods...................................................................................................................................................................... 4

Results..............................................^ 5

Qimlity assurance..................................................................................._^ 5

Bed-sediment data................................................................................................................................................................. 9

Methods...................................................................................................................................................................... 9

Results.....................................................................................................^ 10

Quality assurance....................................................................................................................................................... 10

Biological data....................................................................................................................................................................... 11

Methods..........................................^ 11

Results..................................................................................................................................^ 11

Quality assurance....................................................................................................................................................... 12

Statistical summaries of data................................................................................................................................................. 12

Selected references...................................................................................................^^ 12

Data...........................................^ 15

ILLUSTRATION

Figure 1. Map showing location of study area................................................................................................................... 2

TABLES

Table 1. Type and period of data collection at sampling stations in the upper Clark Fork basin, Montana.................... 3

2. Properties and constituents analyzed in samples of water, bed sediment, and biota from the upper

Clark Fork basin, Montana............................................................................................................................. 4

3. Data-quality objectives for analyses of water-quality samples collected in the upper Clark Fork basin,

Montana.......................................................................................................................................................... 7

4. Water-quality data for the upper Clark Fork basin, Montana, October 1993 through September 1994............ 16

5.-10. Daily streamflow and suspended-sediment data, October 1993 through September 1994, for:

5. Silver Bow Creek at Opportunity, Montana.............................................................................................. 32

6. Silver Bow Creek at Warm Springs, Montana......................................................................................... 36

7. Clark Fork at Deer Lodge, Montana......................................................................................................... 40

8. Clark Fork at Turah Bridge, near Bonner, Montana.................................................................................. 44

9. Blackfoot River near Bonner, Montana..................................................................................................... 48

10. Clark Fork above Missoula, Montana....................................................................................................... 52

11. Chemical analyses of field replicates for water samples, upper Clark Fork basin, Montana............................. 56

12. Precision of chemical analyses of field replicates for water samples, upper Clark Fork basin, Montana......... 59

13. Precision of chemical analyses of laboratory replicates for water samples, upper Clark Fork basin,

Montana..........................................................................................................................................^ 60

14. Recovery efficiency for trace-element analyses of laboratory-spiked deionized-water blanks......................... 61

15. Recovery efficiency for trace-element analyses of laboratory-spiked stream samples, upper Clark

Fork basin, Montana....................................................................................................................................... 62

16. Chemical analyses of field blanks for water samples......................................................................................... 63

17. Trace-element analyses of fine-grained bed sediment, upper Clark Fork basin, Montana, August 1994.......... 66

18. Trace-element analyses of bulk bed sediment, upper Clark Fork basin, Montana, August 1994...................... 67

CONTENTS Hi
TABLES-Continued

Page

Table 19. Recovery efficiency for trace-element analyses of standard reference materials for bed sediment.................. 68

20. Trace-element analyses of procedural blanks for bed sediment........................................................................ 69

21. Trace-element analyses of aquatic insects, upper Clark Fork basin, Montana, August 1994........................... 70

22. Recovery efficiency for trace-element analyses of standard reference material for biota................................. 72

23. Trace-element analyses of procedural blanks for biota..................................................................................... 73

24. Statistical summary of water-quality data for the upper Clark Fork basin, Montana, March 1985 through

September 1994............................................_^ 74

25. Statistical summary of the fine-grained bed-sediment data for the upper Clark Fork basin, Montana,

August 1986 through August 1994................................................................................................................ 90

26. Statistical summary of bulk bed-sediment data for the upper Clark Fork basin, Montana, August 1993

through August 1994...................................................................................................................................... 93

27. Statistical summary of biological data for the upper Clark Fork basin, Montana, August 1986 through

August 1994........................................................._^ 96

CONVERSION FACTORS AND ABBREVIATED WATER-QUALITY UNITS

_________________Multiply_______________By_____________To obtain________________

cubic foot per second (ft3/s) 0.02832 cubic meter per second

foot (ft) 0.3048 meter (m)

gallon (gal) 3.785 liter (L)

inch (in.) 25.4 millimeter (mm)

inch (in.) 25,400 micrometer (um)

mile (mi) 1.609 kilometer

ounce (oz) 28.35 gram (g)

part per million 1 microgram per gram (ug/g)

square mile (mi2) 2.59 square kilometer 

____________ton per day (ton/d)_____________907.2_____________kilogram per day_____________

Temperature can be converted from degrees Celsius (°C) to degrees Fahrenheit (°F) by the equation:

°F = 9/5 (°C) + 32 

Abbreviated water-quality units used in this report:

ug/g micrograms per gram

ug/L micrograms per liter

ug/mL micrograms per milliliter

uS/cm microsiemens per centimeter at 25 °C

mg/L milligrams per liter

Water-year definition:

A water year is the 12-month period from October 1 through September 30. It is designated by the calendar year in which it ends.

iv Water-Quality, Bed-Sediment, and Biological Data (October 1993 through September 1994) and Statistical Summaries of Data 

for Streams in the Upper Clark Fork Basin, Montana.
Water-Quality, Bed-Sediment, and Biological Data 

(October 1993 through September 1994) and Statistical 

Summaries of Data for Streams in the Upper Clark Fork 

Basin, Montana

By John H. Lambing, Michelle I. Hornberger, Ellen V. Axtmann, anc/Kent A. Dodge

Abstract

Water, bed sediment, and biota were sampled 

in streams from Butte to below Missoula as part of 

a program to characterize aquatic resources in the 

upper Clark Fork basin of western Montana. 

Sampling stations were located on the Clark Fork 

and major tributaries. Water-quality data were 

obtained periodically at 16 stations during October 

1993 through September 1994 (water year 1994). 

Bed-sediment and biological data were obtained at 

11 of the 16 stations in August 1994. The primary 

constituents analyzed were trace elements 

associated with mine tailings from historical 

mining and smelting activities.

Water-quality data include concentrations 

of major ions, trace elements, and suspended 

sediment in samples collected periodically during 

water year 1994. Daily values of streamflow, 

suspended-sediment concentration, and suspended-sediment discharge are given for six 

stations. Bed-sediment data include trace-element 

concentrations in the fine-grained and bulk 

fractions. Biological data include trace-element 

concentrations in whole-body tissue of aquatic 

benthic insects. Quality-assurance data are 

rep9rted for analytical results of water, bed 

sediment, and biota. Statistical summaries of 

water-quality, bed-sediment, and biological data 

are provided for the period of record at each 

station since 1985.

INTRODUCTION

The Clark Fork originates near Warm 

Springs in western Montana at the confluence of 

Silver Bow and Warm Springs Creeks (fig. 1). 

Alone the 148-mi reach of stream from Silver Bow 

CreeK in Butte to the Clark Fork at Milltown 

Reservoir, six majpr tributaries enter: Blacktail 

Creek, Warm Springs Creek, Little Blackfoot 

River, Flint Creek, Rock Creek, and Blackfoot 

River. Principal surface-water uses in the 6,000- 

mi2 Clark Fork basin above Missoula include

irrigation, stock watering, light industry, 

hydroelectric power generation, and habitat for 

trout fisheries. Current land uses primarily are 

cattle production, logging, mining, and recreation. 

Large-scale mining and smelting had been 

prevalent land uses in the upper basin for more 

than one hundred years, but are now largely 

discontinued.

Deposits of copper, gold, silver, and lead 

ores were extensively mined, milled, and smelted 

in the drainages of Silver Bow and Warm Springs 

Creeks from about 1860 to 1980. Moderate- and 

small-scale mining also occurred in the basins of 

most of the major tributaries to the upper Clark 

Fork. Tailings derived from mineral processing 

commonly contain large quantities of trace 

elements such as cadmium, copper, lead, and zinc 

that can accumulate to potentially toxic levels in 

aquatic organisms. Tailings have been eroded and 

transported downstream since the late 1800's and 

redeposited in stream channels, on flood plains, 

and in Warm Springs Ponds and Milltown 

Reservoir. The river continues to erode, transport, 

and redeposit tailings-laden sediment along the 

river and flood plain corridor, especially during 

high flows.

Concern about the potential toxicity of 

tailings to aquatic biota and human health has 

resulted in a comprehensive effort by State, 

Federal, and private entities to characterize the 

aquatic resources in the upper Clark Fork basin to

g

uide and monitor remedial cleanup activities, 

stablishment of a long-term data base was 

considered necessary to statistically detect trends 

over time in order to evaluate the effectiveness of 

remediation. Water-quality data have been 

collected by the U.S. Geological Survey (USGS) 

at selected sites in the upper Clark Fork basin since 

1985 (Lambing, 1987,1988,1989,1990, and 1991; 

Lambing and others, 1994). Trace-element data 

for bed sediment and biota (aquatic benthic 

insects) have been collected annually since 1986 at 

selected sites as part of studies on bed-sediment 

contamination and bioaccumulation of metals

Abstract
Base from U.S. Geological Survey State 

base map, 1=1,000,000, 

1966

EXPLANATION 

12324200 STATION AND NUMBER

Streamflow gaging 

A Continuous record 

A Periodic measurement

Water quality, bed eediment, biota 

-V Periodic water quality 

^.Daily suspended sediment 

V~0nce- annual bed sediment

"V Once-annual biota

10 20 MILES

10 20 KILOMETERS

Figure 1. Location of study area.

conducted by the USGS National Research 

Program (Axtmann and Luoma, 1991; Cain and 

others, 1992; Lambing and others, 1994). In 

March 1993, an expanded sampling program for 

water, bed sediment, and biota was implemented 

in cooperation with the U.S. Environmental 

Protection Agency.

The purpose of this report is to present 

water-quafity data for 16 stations and traceelement data for bed sediment and biota at 11 

stations in the upper Clark Fork basin collected 

from October 1993 through September 1994 

(water year 1994). Quality-assurance data are 

presented for water quality, bed sediment, and

biota. Statistical summaries also are provided for 

water-quality, bed-sediment, and biological data 

collected since 1985.

SAMPLING LOCATIONS AND TYPES OF 

DATA

Sampling stations in the upper Clark Fork 

basin are located on b9th the Clark Fork mainstem 

and major tributaries from Butte to below 

Missoula (fig. 1). Mainstem sites were selected to 

divide the upper Clark Fork into reaches of 

relatively uniform length, with each reach 

encompassing either a major tributary or

2 Water-Quality, Bed-Sediment, and Biological Data (October 1993 through September 1994) and Statistical Summaries of Data for 

Streams in the Upper Clark Fork Basin, Montana.
depositjonal environment (Warm Springs Ponds 

and Milltown Reservoir). Tributaries were 

sampled to describe water-quality characteristics 

for major hydrologic sources in the upper basin 

and to provide reference comparisons to the 

mainstem for bed sediment and biota. Waterquality data were obtained periodically at 16 

stations; daily suspended-sediment data were 

obtained at 6 of these stations. Bed-sediment and 

biological data were obtained once-annually at 11 

of these stations (table 1).

A list of properties and constituents analyzed 

in samples of water, bed sediment, and biota is 

given in table 2. Results of analyses for water, bed 

sediment, and biota for water year 1994 are listed 

in tables 4 through 23 at the back of the report. 

Statistical summaries of water-quality, bedsediment, and biological data collected since 1985 

are given in tables 24-27 at the back of the report.

Quality assurance of data was maintained

through the use of documented procedures 

designed to provide environmentally 

representative data. Acceptable performance of 

the procedures was verified with quality-control 

samples that were collected systematically to 

provide a measure of the accuracy, precision, and 

bias of the environmental data and to identify 

problems associated with sampling, processing, or 

analysis.

WATER-QUALITY DATA

Water-quality data consist of measurements 

of physical properties and concentrations of 

chemical and physical constituents analyzed in 

stream samples. Samples were collected 6 to 10 

times per year at a schedule designed to adequately 

describe seasonal and hydrologic variability.

Table 1. Type and period of data collection at sampling stations in the upper Clark Fork basin, Montana

[Abbreviation: P, present. Symbol: --, no data]

Station 

number (fig. D

12323230

12323250

12323600

12323750

12323770

12323800

12324200

12324590

12324680

12331500

12331800

12334510

12334550

12340000

12340500

12353000

Station name

Blacktail Creek at Harrison Avenue, 

at Butte

Silver Bow Creek below Blacktail 

Creek, at Butte

Silver Bow Creek at Opportunity

Silver Bow Creek at Warm Springs

Warm Springs Creek at Warm 

Springs

Clark Fork near Galen

Clark Fork at Deer Lodge

Little Blackfoot River near Garrison

Clark Fork at Goldcreek

Flint Creek near Drummond

Clark Fork near Drummond

Rock Creek near Clinton

Clark Fork at Turah Bridge, near 

Bonner

Blackfoot River near Bonner

Clark Fork above Missoula

Clark Fork below Missoula

Continuousrecord 

streamflow

10/83-P

07/88-P

03/72-09/79, 

04/93-P

10/83-P

07/88-P

10/78-P

10/72-P

10/77-P

08/90-P

04/93-P

10/72-P

05/86-P

10/39-P

03/29-P

10/29-P

Periodic 

water 

quality1

03/93-P

03/93-P

03/93-P

03/93-P

03/93-P

07/88-P

03/85-P

03/85-P

03/93-P

03/85-P

03/93-P

03/85-P

03/85-P

03/85-P

10/89-P

10/78-P

Daily 

suspended 

sediment

-

03/93-P

04/93-P

~

~

03/85-09/86, 

04/87-P

~

~

03/85-P

07/86-04/87, 

06/88-P

07/86-04/87, 

06/88-P

~

Finegrained 

bed sediment2

-

07/92-P

08/93

~

08/87-P

08/86-P

08/86-P

07/92-P

08/86-P

08/86-P

08/87-P

08/86-P

08/86-P

--

08/86-P

Bulk 

bed sediment2

~

08/93

08/93

~

08/93

08/93

08/94

08/93

08/93

08/93

08/93

08/93

08/93

-

08/93

Biota2

--

08/94

08/93

08/87-P

08/86-P

08/87-P

07/92-P

08/86-P

08/86-P

08/87-P

08/86-P

08/86-P

--

08/86-P

measurements of physical properties and laboratory analyses of major ions, trace elements, and suspended sediment. Prior to 

March 1993, laboratory analyses included only trace elements and suspended sediment, with the exception of Clark Fork below 

Missoula.

laboratory analyses of trace elements. 

Bed sediment and biota sampled about 30 miles downstream from water-quality station to conform to previous sampling location.

WATER-QUALITY DATA
Table 2. Properties and constituents analyzed in samples of water, bed 

sediment, and biota from the upper Clark Fork basin, Montana

Water

Property

Streamflow

Specific conductance

PH

Temperature

Constituent

Hardness

Calcium

Magnesium

Sodium

Potassium

Alkalinity

Sulfate

Chloride

Fluoride

Silica

Dissolved solids

Arsenic

Cadmium

Copper

Iron

Lead

Manganese

Zinc

Suspended 

sediment

Bed 

sediment

Constituent

Cadmium

Chromium

Copper

Iron

Lead

Manganese

Nickel

Silver

Zinc

Biota

Constituent

Cadmium

Chromium

Copper

Iron

Lead

Manganese

Nickel

Zinc

Methods

Cross-sectional water samples were 

collected from multiple verticals across the stream 

using depth-integration methods described by Guy 

and Norman (1970), USGS (1977), and Knapton 

(1985). These methods provide a vertically and 

laterally discharge-weighted sample that is 

representative of the entire flow through the cross 

section of a stream. Sampling equipment 

consisted of standard USGS depth-integrating 

suspended-sediment samplers (DH-81 and D74TM) which are either constructed of plastic or 

equipped with nylon nozzles and coated with a 

non-metallic epoxy paint.

Onsite measurements of water temperature, 

specific conductance, and pH were maae during 

collection of periodic water-quality samples. 

Onsite sample processing, including filtration and 

acidification, was performed according to 

procedures described by Horowitz and others 

(1994), Ward and Harr (1990), USGS (1977), and 

Knapton (1985). Instantaneous streamflow at the 

time of water sampling was determined at all 

stations, either by direct measurement or from 

stage-discharge rating tables (Rantz and others, 

1982).

Water samples were analyzed for the

constituents listed in table 2 by the USGS National 

Water Quality Laboratory (NWQL) in Aryada, 

Colo. The trace elements arsenic, cadmium, 

copper, iron, lead, manganese, and zinc were 

analyzed for both dissolved and total-recoverable 

concentrations. Analytical methods are described 

by Fishman and Friedman (1989) and Fishman 

(1993).

Cross-sectional water samples also were 

collected for analysis of suspended sediment 

whenever periodic water-quality samples were 

collected. These samples were analyzed for 

suspended-sediment concentration and sand-silt 

distribution (percent less than 0.062 mm diameter) 

by the USGS sediment laboratory in Helena, 

Mont., according to methods described by Guy 

(1969) and Lambing and Dodge (1993).

At the six daily suspended-sediment stations 

(table H, suspended-sediment samples were 

collected 2 to 7 times per week. These samples 

were collected by local contracted observers using 

the depth-integration method at a single vertical 

near mid-stream. The samples were analyzed for 

suspended-sediment concentration and were used 

to determine daily mean suspended-sediment 

concentrations according to methods described by 

Porterfield(1972).

4 Water-Quality, Bed-Sediment, and Biological Data (October 1993 through September 1994) and Statistical Summaries of Data for 

Streams in the Upper Clark Fork Basin, Montana.
Results

Water-quality data for samples collected 

periodically during October 1993 through 

September 1994 (water year 1994) are presented 

in table 4. The types of data include instantaneous 

streamflpw, onsite measurements of water-quality 

properties, and analytical results for chemical 

constituents and suspended sediment.

Daily streamflow and suspended-sediment 

data for water year 1994 at the six daily 

suspended-sediment stations are given in tables 5 

to 10. Monthly descriptive statistics for each 

parameter are provided along with totals for the 

annual discharge of water and suspended 

sediment.

Quality Assurance

Quality-assurance procedures used for the 

collection and field processing of water-quality 

samples are described by Horowitz and others 

(1994), Ward and Harr (1990), Edwards and 

Glysson (1988), Knapton andNimick (1991), and 

Knapton (1985). Standard procedures used by the 

NWQL for internal sample handling and quality 

assurance are described by Fnedman and 

Erdmann (1982), Jones (1987), and Pritt and 

Raese (1992). Quality-assurance procedures used 

by the Montana District sediment laboratory are 

described by Lambing and Dodge (1993).

The quality of analytical results reported for 

water-quality samples was evaluated by qualitycontrol samples that were submitted from the field 

and analyzed concurrently in the laboratory with 

routine samples. These quality-control samples 

consisted of replicates, spikes, and blanks which 

provide quantitative information on the precision 

and bias of the overall field and laboratory process. 

Each type of quality-control sample was 

submitted at a proportion equivalent to about 5 

percent of the total number of water-quality 

samples. Therefore, the total number of 

quanty-control samples represented about 15 

percent of the total number of water-quality 

samples.

In addition to quality-control samples 

submitted from the field, internal qualityassurance practices within the laboratory are 

performed systematically to provide quality 

control of analytical procedures (Pritt and Raese, 

1992). These internal practices include analyses 

of quality-control samples such as calibration 

standards, standard reference water samples, 

replicate samples, deionized-water blanks, or 

spiked samples at a proportion equivalent to at 

least 10 percent of the sample load. The NWQL

participates in a blind-sample program where 

standard reference water samples prepared by the 

USGS Branch of Quality Assurance are routinely 

inserted into the sample line for each analytical 

method at a frequency proportipnal to the sample 

load. The NWQL alsp participates in external 

evaluation studies twice-yearly with the U.S. 

Environmental Protection Agency, the Canadian 

Center for Inland Water, and the Quality 

Assurance Section of the USGS Branch of 

Technical Development and Quality Systems to 

assess analytical performance.

Replicate samples are two or more samples 

considered to be essentially identical in 

composition. Analyses of replicate samples 

indicate the precision (reproducibility) of results. 

Precision is affected by numerous sources of 

variability within the field and laboratory 

environments, including sample collection, 

sample processing, and sample analysis. To 

provide data on overall precision, replicate 

samples were obtained in the field by splitting a 

composite stream sample. Analyses of these field 

repficates indicate the reproducibility of 

environmental data, which is affected by the 

combined variability of field and laboratory 

processes to which the sample is exposed.

Analytical precision was evaluated by 

making replicate analyses of an individual sample 

selected randomly in the laboratory from the 

group of samples comprising each analytical run. 

A separate analysis of the sample was made at the 

beginning and end of each analytical run to 

provide information on laboratory analytical 

precision independent of possible effects on 

precision caused by field collection and processing 

of samples.

Spiked samples are used to evaluate the 

ability of an analytical method to accurately 

measure a known amount of analyte added to a 

sample. Deionized-water blanks and aliquots of 

stream samples were spiked in the laboratory with 

known amounts of the trace elements analyzed in 

water samples. Analyses of spiked blanks indicate 

if the spiking procedure and analytical method are 

within control for a water matrix that is 

presumably free of chemical interference. 

Analyses of spiked aliquots of stream samples 

indicate if the chemical matrix of ambient stream 

water interferes with the analytical measurement 

and whether these interferences could contribute 

significant bias to reported trace-element 

concentrations for stream samples.

Blank samples of deionized water were 

routinely analyzed to identify the presence and 

magnitude of contamination that potentially could 

bias analytical results. The particular type of blank 

sample routinely tested was a "field" blank. Field

WATER-QUALITY DATA
blanks are aliquots of deionized water that are 

certified as trace-element free and are processed 

through the sampling equipment used to collect 

stream samples. These blanks are then subjected 

to the same processing (sample splitting, filtration, 

preservation, transportation, and laboratory 

handling^ as stream samples. Blank samples are 

analyzed for the same constituents as those of 

stream samples to identify whether any detectable 

concentrations exist.

All water samples were handled in 

accordance with chain-of-custody procedures that 

provide documentation of sample identity, 

shipment, receipt, and laboratory handling. All 

samples submitted from a sampling episode were 

stored and analyzed as a group independent of 

other samples submitted to the NWQL. Therefore, 

statistical descriptions of quality-control data 

generated for this program are directly applicable 

to the analytical results for stream samples 

reported herein. In addition, internal laboratory 

quality-control data provide ongoing maintenance 

of accuracy and precision for the analytical 

process.

Data-auality objectives (table 3) were 

established for water-quality data as part of the 

study plan for the long-term monitoring program. 

The objectives identify analytical requirements of 

detectability and serve as a guide for identifying 

questionable data by establishing limits for 

precision and bias of laboratory results. 

Comparisons of quality-control data to objectives 

are used to evaluate whether sampling and 

analytical procedures are producing 

environmentally representative data in a consistent 

manner. Data that did not meet the objectives were 

evaluated for acceptability, and corrective action 

was taken, when appropriate.

The precision of analytical results for a 

constituent can be determined by estimating a 

standard deviation from the differences of several 

sets of replicate measurements. These replicate 

measurements may consist either of individual 

analyses of a pair of samples considered to be 

essentially identical (field replicates) or multiple 

analyses of an individual sample (laboratory 

replicates). The differences in concentration 

between replicate analyses can be used to estimate 

a standard deviation according to the following 

equation (Taylor, 1987):

S = (1)

S = standard deviation of the difference in 

concentration between replicate analyses,

d = difference in concentration between 

each pair of replicate analyses, and

k = number of pairs of replicate analyses.

Precision can also be expressed as a relative 

standard deviation (RSD), in percent, which is 

computed from the standard deviation and the 

mean concentration for all the replicate analyses. 

Expressing precision relative to a mean 

concentration standardizes comparison of 

precision among individual constituents. The 

RSD, in percent, is calculated according to the 

following equation (Taylor, 1987):

RSD = - x 100 (2)

where:

where:

RSD = relative standard deviation, 

S = standard deviation, and

x - mean of all replicate concentrations.

Paired chemical analyses of field replicates 

are presented in table 11. The overall precision 

estimated for each constituent based on these 

paired results is reported in table 12. Statistics for 

precision of field-replicate analyses were based on 

the values reported in table 11 which are rounded 

to standard USGS reporting levels for the 

particular constituent and its analytical method 

(Timme, 1994). Analytical precision for 

constituents based on laboratory-replicate 

analyses of individual samples randomly selected 

by the laboratory is reported in table 13. Statistics 

for analytical precision of laboratory-replicate 

analyses are based on unrounded values stored in 

laboratory data files. Concentrations less than the 

minimum reporting level (censored values) were 

included in the calculations by arbitrarily 

substituting a value of one-half the reporting level.

The data-quality objective for analytical 

precision, based on laboratory-replicate analyses, 

is a maximum relative standard deviation of 20 

percent. Precision estimates for laboratoryreplicate analyses were within the 20-percent 

relative standard deviation limits for all 

constituents (table 13). The precision data, 

therefore, indicate acceptable reproducibiliry of 

analytical results.

Although the data-quality objectives for 

precision are not directly applicable to field 

replicates owing to the additional potential for

6 Water-Quality, Bed-Sediment, and Biological Data (October 1993 through September 1994) and Statistical Summaries of Data for 

Streams in the Upper Clark Fork Basin, Montana.
Table 3. Data-quality objectives for analyses of water-quality samples collected in the upper Clark Fork basin, 

Montana

[Abbreviations: ug/L, micrograms per liter; uS/cm, microsiemens per centimeter at 25 degrees Celsius; mg/L, milligrams per liter. 

Symbol: , not determined]

Data-quality objectives

Detectability Precision Bias

Maximum relative

Property or constituent

Specific conductance

pH

Hardness

Calcium, dissolved

Magnesium, dissolved

Sodium, dissolved

Potassium, dissolved

Alkalinity, dissolved

Sulfate, dissolved

Chloride, dissolved

Fluoride, dissolved

Silica, dissolved

Arsenic, total recoverable

Arsenic, dissolved

Cadmium, total recoverable

Cadmium, dissolved

Copper, total recoverable

Copper, dissolved

Iron, total recoverable

Iron, dissolved

Lead, total recoverable

Lead, dissolved

Manganese, total recoverable

Manganese, dissolved

Zinc, total recoverable

Zinc, dissolved

Sediment, suspended

Sediment, suspended,

(percent finer than 0.062 mm)

Minimum _._._., 

., standard deviation reporting i of laboratory

replicate analyses, in units in percent

1

.1

1

.1

.1

.1

.1

1

.1

.1

.1

.1

1

1

1

.1

1

1

10

3

1

.5

10

1

10

3

1

1

uS/cm

units

mg/L as CaCC>3

mg/L

mg/L

mg/L

mg/L

mg/L as CaCO3

mg/L

mg/L

mg/L

mg/L

ug/L

ug/L

ug/L

ug/L

ug/L

ug/L

ug/L

ug/L

ug/L

ug/L

ug/L

ug/L

ug/L

ug/L

mg/L

percent

2

5

20

20

20

20

20

20

20

20

20

20

20

20

20

20

20

20

20

20

20

20

20

20

20

20

-

-

Maximum 

deviation of 

spike recovery, 

in percent

-

-

--

~

~

-

~

-

--

-

-

~

25

25

25

25

25

25

25

25

25

25

25

25

25

25

~

-

WATER-QUALITY DATA
variability resulting from field sampling and 

processing, relative standard deviations estimated 

From differences between analytical results of 

field replicates also were within 20 percent for all 

constituents except dissolved iron and dissolved 

lead (table 12). The large deviation in 

concentrations of dissolved iron was the result of 

filtration of replicate samples through two 

different types of filters as part of a test of new 

USGS protocols. Apparently, colloidal iron is 

retained more effectively on flat membrane filters 

compared to the convoluted surface of capsule 

filters recommended in new protocols. Other 

elements displayed no discernible difference 

between filters. Because detection of long-term 

trends could be affected by converting to new 

equipment having different sampling characteristics, it was decided to continue usage of the flat 

membrane filters.

Replicate data for dissolved lead also 

exceeded the 20-percent precision limit for 

analyses of field replicates. This exceedance 

resulted from a predominance of low 

concentrations whicn produced several pairs 

where the concentration of one sample was at or 

slightly greater than the minimum reporting level 

and the concentration of the other sample was less 

than the reporting level. Arbitrarily substituting 

one-half me minimum reporting level for the 

censored values in these cases produced relatively 

large relative standard deviations. Replacing onehalf the value with the actual minimum reporting 

level for those sample pairs resulted in an 

acceptable relative standard deviation of 19 

percent for dissolved lead.

Analyses of paired spiked and unspiked 

samples enable calculation of the spike recovery 

for each trace element and thereby provide a 

measure of the recovery efficiency for the 

analytical method. Spike recovery, in percent, 

was calculated using the following equation:

The data-quality objective for acceptable 

spike recovery of trace elements in water samples 

was a maximum deviation of 25 percent from a 

theoretical 100-percent recovery of added 

constituent. At the laboratory, a spiked deionizedwater blank and one spiked aliquot of stream 

sample were prepared and analyzed with the 

sample set. If the spike recovery for a trace 

element was outside a range of 75 to 125 percent, 

the sample set for the analytical run was 

reanalyzed for the trace element. Results of spike 

recoveries of individual trace elements in spiked 

deionized-water blanks and spiked stream samples 

are presented in tables 14 and 15, respectively.

The mean spike recovery for deionizedwater samples spiked with trace elements ranged 

from 94.6 to 109.3 percent. The mean spike 

recovery for spiked stream samples ranged from 

96.6 to 106.9 percent. The 95-percent confidence 

intervals for the mean (Taylor, 1987) of spike 

recovery for each constituent did not exceed a 25- 

percent deviation from an expected 100-percent 

recovery. Consequently, spike recoveries tor each 

trace element were within the limits of dataquality objectives and indicate acceptable 

analytical performance. However, bias is 

indicated if the confidence interyal does not 

include 100 percent. Confidence intervals for 

analytical recoveries of total-recoverable arsenic, 

dissolved copper, and dissolved lead in stream 

samples did not include 100 percent. For these 

elements, the bias was slightly low for dissolved 

copper (93.3-99.8 percent) and slightly high for 

total-recoverable arsenic (101-113 percent) and 

dissolved lead (101-105 percent). Because all 

identified bias was small and mean spike 

recoveries met data-quality objectives, no 

adjustments were made to analytical results for 

stream samples on the basis of spike recoveries.

Analytical results for field blanks are 

presented in table 16. A field blank with

Spike recovery in percent = spiked sample concentration unspiked sample concentration x 100

spike concentration (3)

8 Water-Quality, Bed-Sediment, and Biological Data (October 1993 through September 1994) and Statistical Summaries of Data for 

Streams in the Upper Clark Fork Basin, Montana.
constituent concentrations equal to or less than the 

minimum reporting level for the analytical method 

indicates that the entire sample collection, 

processing, and analytical process is presumably 

Free of significant contamination. If detectable 

concentrations in field blanks were equal to or 

greater than twice the minimum reporting level 

(typical measurement precision at the detection 

level), the concentrations were noted. Sporadic, 

infrequent exceedances of twice the minimum 

reporting level probably represent random 

contamination or instrument calibration error that 

is not persistent in the process and which is not 

likely to cause significant positive bias in 

analytical results. However, the field blank for the 

next sample set is evaluated for a consistent trend 

that may indicate systematic contamination. If 

concentrations for a particular constituent exceed 

twice the minimum reporting level in field blanks 

from two consecutive field trips, archived blank 

samples collected from individual components of 

the processing sequence are submitted for analysis 

in order to identify the source of contamination.

Constituent concentrations in field-blanks 

were almost always less than the minimum 

reporting level. Exceedances of twice the 

minimum reporting level generally were 

infrequent and random, thereby indicating no 

systematic positive bias of reported water-quality 

data. There were no occurrences of concentrations 

greater than the minimum reporting level in two 

consecutive blank samples.

Values for lead in four samples (and copper 

in one of those samples) collected between 

October and December 1993 were deleted as a 

result of field contamination identified and 

described in Lambing and others (1994). These 

samples represent the last set of data affected by 

acid-rinsing of the D-74TM sampler. The deleted 

lead and copper values are indicated as dashes in 

table 4.

BED-SEDIMENT DATA

Bed-sediment data consist of analyses of 

solid-phase concentrations of trace elements in the 

fine-grained and bulk fractions. Bed-sediment 

samples are collected pnce-annually during low, 

stable flow conditions to facilitate data 

comparisons between years.

Methods

Bed-sediment samples were collected in 

August 1994 using protocols described by E.V. 

Axtmann (U.S. Geological Survey, written 

commun., 1994). Samples were collected using an

acid-washed polypropylene scoop from the 

surfaces of streambed deposits in low-velocity 

areas near the edge of the stream. Samples were 

collected from both sides of the stream whenever 

possible. Three composite samples of fine-grained 

bed sediment and one to three composite samples 

of bulk bed sediment were collected at each site.

Individual samples of fine-grained bed 

sediment were collected from the surfaces of three 

to five randomly selected deposits along pool 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 0.064-mm nylon-mesh sieve 

using ambient stream water. The fraction of bed 

sediment in each composite sample that was finer 

than 0.064 mm was transferred to an acid-washed 

500-mL high-density polyethylene bottle and 

transported to the laboratory on ice.

Individual samples of bulk sediment also 

were collected from the surfaces of three to five 

randomly selected deposits. Because the 

streambed at most sampling locations is 

predominantly gravel and cobble, deposits were 

selected where cobbles and gravel could be 

visually avoided and excluded from the samples. 

Therefore, bulk samples generally are composed 

of particles smaller than about 10 mm in diameter. 

The individual unsieved samples were composited 

and stored in acid-washed polyethylene Dottles 

that were transported to the laboratory on ice.

Bed-sediment samples were processed at the 

USGS National Research Program laboratory in 

Boulder, Colo. Fine-grained and bulk bedsediment samples were oven-dried at 60 °C and 

ground using an acid-washed ceramic mortar and 

pestle. Duplicate aliquots of approximately 0.6 g 

of sediment from each composite fine-drained bed 

sediment sample were digested using a hot, 

concentrated nitric acid reflux according to 

methods described by Luoma and Bryan (1981). 

Triplicate aliquots were analyzed from each 

C9mposite sample of bulk bed sediment. After a 

digestion period of up to several weeks, the 

aliquots were evaporated to dryness on a hot plate. 

The dry residue was redissolved with 20 mL of 

0.6 N (normal) hydrochloric acid. The 

reconstituted aliquots then were filtered through a 

0.45-|im filter using a syringe and in-line 

disposable filter cartridge. Tne filtrate was 

subsequently diluted to either a 1:5 or 1:10 ratio 

with 0.6 N hydrochloric acid. These final 

solutions then were analyzed for cadmium, 

chromium, copper, iron, manganese, nickel, silver, 

and zinc using Inductively Coupled Argon Plasma 

Emission Spectroscopy (ICAPES) at the USGS

BED-SEDIMENT DATA 9
National Research Program laboratory in Menlo 

Park, Calif. Lead was analyzed by flame atomic 

absorption (AA) at the USGS National Research 

Program laboratory in Boulder, Colo.

Results

Solid-phase concentrations of trace elements 

measured in samples of fine-grained bed sediment 

and bulk bed sediment collected during August 

1994 are summarized in tables 17 and 18, 

respectively. Liquid-phase concentrations, in jj,g/ 

mL, that were analyzed in the reconstituted 

aliquots of digested bed sediment were converted 

to solid-phase concentrations, in jag/g, using the 

following equation:

x volume of digested sample, in mL 

dry weight of sample, in g x dilution ratio ^ '

The reported solid-phase concentrations in table 

17 and 18 represent the means of all analyses of 

replicate aliquots from each composite sample 

collected at the site. Because the conversion from 

liquid-phase to solid-phase concentration is 

dependent on both the dilution ratio and the dry 

weight of the sample, minimum reporting levels 

for some trace elements may differ between 

stations.

Quality Assurance

The protocols for field collection and 

processing of bed-sediment samples are designed 

to prevent contamination from metal sources. 

Non-metallic sampling and processing equipment 

was acid-washed and rinsed with deionized water 

prior to the first sample collection. Nylon-mesh 

sieves were washed in a laboratory-grade 

detergent and rinsed with deionized water. All 

equipment was given a final rinse onsite with 

stream water. Sampling equipment that was 

reused at each site was rinsed between sites with 

10-percent nitric acid, deionized water, and stream 

water. Separate sieves were used at each site and 

therefore did not require between-site cleaning. 

Samples were collected along an increasing 

concentration gradient from the downstream 

tributaries and mainstem to the upstream 

tributaries and mainstem to minimize any effects 

from potential station-to-station carryover 

contamination.

Quality assurance of analytical results for

bed sediment included laboratory instrument 

calibration with standard solutions and analysis of 

quality-control samples designed to identify the 

presence and magnitude of bias (E. V. Axtmann, 

U.S. Geological Survey, written commun., 1994). 

Quality-control samples consisted of standard 

reference materials and procedural blanks. Each 

type of sample was analyzed in a proportion 

equivalent to about 10 to 20 percent of me total 

number of bed-sediment samples.

Standard reference materials (SRM) have 

certified concentrations of trace elements. 

Replicate analyses of standard reference materials 

are used to indicate the repeatability of 

measurements and the ability of the method to 

accurately measure a known quantity of a 

constituent. Recovery efficiency or trace-element 

analyses of standard reference materials for bed 

sediment is summarized in table 19. Two standard 

reference materials consisting of agricultural soils 

representing low and high concentrations of trace 

elements were analyzed to test recovery efficiency 

for a range of concentrations generally similar to 

those occurring in the upper Clark Fork basin. The 

digestion process used to analyze bed-sediment 

samples is not a "total" digestion (does not liberate 

elements associated with crystalline lattices); 

therefore, 100-percent recovery may not be 

achieved for elements strongly bound to the 

sediment. The percent recovery of trace elements 

in standard reference materials under such 

conditions serve to indicate which trace elements 

display strong sediment-binding characteristics 

ana whether analytical recovery is consistent 

between multiple sets of analyses. Although dataquality objectives have not been established for 

bed sediment, elements with mean recoveries 

outside a 25-percent deviation from complete 

recovery were chromium and lead for the lowconcentration range (SRM 2709), and chromium 

and silver for the hign-concentration range (SRM 

2711). Mean recoveries were low for these 

elements, indicating that the digestion during 

sample preparation did not release all of the 

element from the solid-phase matrix.

Procedural blanks for bed-sediment samples 

consisted of the reagents used for sample digestion 

and reconstitution. Concentrated nitric acid used 

for sample digestion was heated and evaporated to 

dryness. After evaporation, 0.6 N hydrochloric 

acid was added quantitatively to the dry residue to 

obtain the same dilution ratio as that used in the 

analysis of bed sediment. Procedural blanks, 

therefore, represent the same chemical matrix as 

the solution used to process bed-sediment 

samples. Analytical results for procedural blanks 

indicate the presence and magnitude of potential 

contamination associated with sample handling

10 Water-Quality, Bed-Sediment, and Biological Data (October 1993 through September 1994) and Statistical Summaries of Data 

for Streams in the Upper Clark Fork Basin, Montana.
and analysis in the laboratory environment. 

Results of trace-element analyses of procedural 

blanks for bed sediment are in table 20.

Analytical results of procedural blanks are 

reported as a liquid-phase concentration, in (ig/ 

mL, which is equivalent to parts per million. 

Determination of the significance of a detectable 

blank concentration is based on the magnitude of 

the equivalent solid-phase concentration, in ng/g, 

relative to the ambient concentration of the trace 

element in bed-sediment samples. Because 

sample weights of individual aliquots may vary, 

the relative significance of blank concentrations 

may differ among samples. If a detectable blank 

concentration, after conversion to a solid-phase 

concentration, represents 10 percent or more of the 

ambient solid-phase concentration, then the blank 

concentration is subtracted to remove potential 

contamination bias. Almost all procedural blanks 

had concentrations less than analytical detection 

levels, with only one blank for lead haying a 

detectable concentration near the minimum 

reporting level. Therefore, no adjustments were 

made to trace-element concentrations in bedsediment samples on the basis of procedural 

blanks.

BIOLOGICAL DATA

Biological data consist of analyses of solidphase concentrations of trace elements in the 

whole-body tissue of aquatic benthic insects. 

Biota samples were collected once-annually at the 

same stations where bed sediment was sampled 

(table 1). Samples of insects were collected 

concurrently with bed-sediment samples to 

facilitate comparisons of results between years 

and between the accumulation patterns in physical 

and biological matrices.

Methods

Biota samples were collected using 

protocols described by M.I. Hornberger (U.S. 

Geological Survey, written commun., 1994). 

Immature stages or aquatic benthic insects were 

collected using a large nylon-mesh kick net. A 

single riffle at each station was sampled repeatedly 

until an adequate number of individuals was 

collected to provide sufficient mass for analysis. 

Targeted taxa for collection were Hydropsyche 

spp., Family Trichoptera; Arctopsyche grandis, 

Family Trichoptera; and Claassenia sabulosa, 

Family Plecoptera. Samples of each taxon were 

stored separately, by genus, in acid-washed plastic 

containers. Containers were kept on ice in the field 

while the insects were allowed to evacuate the gut

contents in ambient stream water for a period of 

six to eight hours. Excess water then was drained 

and insects were frozen for transport to the 

laboratory.

Biota samples were processed and analyzed 

at the USGS National Research Program 

laboratory in Menlo Park, Calif. Insects were 

thawed and rinsed with ultra-pure dei9nized water 

to remove particulate matter. The insects then 

were sorted to their lowest possible taxonomic 

level. When large numbers of specimens were 

collected from a station, similar-sized individuals 

were composited into replicate subsamples. 

Subsamples were placed in tared scintillation vials 

and oven-dried at 70 °C. Subsamples were 

weighed to obtain a final dry weight and digested 

by reflux using concentrated nitric acid (Cam and 

others, 1992). After digestion, insect samples 

were evaporated to dryness on a hot plate. The dry 

residue was reconstituted in 0.6 N hydrochloric 

acid, filtered through a 0.45-tim filter, and 

analyzed undiluted by ICAPES for cadmium, 

chromium, copper, iron, lead, manganese, nickel, 

and zinc.

Results

Solid-phase concentrations of trace elements 

in whole-body tissue of aquatic insects collected 

during August 1994 are summarized in table 21. 

The variability in the number of composite 

samples between species and between sites 

reflects the difference in insect abundance, with 

number of composite samples increasing with 

abundance of insects. Liquid-phase 

concentrations analyzed in the reconstituted 

samples were converted to solid-phase 

concentrations using equation 4. As in bed 

sediment, minimum reporting levels may differ 

between sites as a result of variable sample 

weights. In general, the smaller the biological 

sample weight (a function of insect abundance! 

the higher the minimum reporting level. 

Therefore, higher minimum reporting levels do 

not necessarily imply a higher trace-element 

concentration in tissue.

Two genera of Hydropsyche were 

collected Hydropsyche morosa group and 

Hydropsyche occiaentalis. Within me morosa 

group, two species (H. cockerelli and H. tana) 

were identified. Results of analyses are listed for 

the individual species within the morosa group 

where positive identification was possible. At 

some sites, sampled insects were not clearly 

identifiable as a specific species but could be 

sufficiently identified as belonging to the morosa 

group. Therefore, results listed for the morosa

BIOLOGICAL DATA 11
group are considered to represent concentrations 

m a sample that may consist of both Hydropsyche 

cockerelli and Hydropsyche tana. In addition, an 

additional Hydropsyche species (H. spp.) has been 

identified as distinct from the other species, but 

having characteristics that would place it in the 

morosa group.

Quality Assurance

The protocols for field collection and 

processing of biota samples are designed to 

prevent contamination from metal sources. Nonmetallic nets, sampling, and processing equipment 

was employed in all sample collection. 

Equipment was acid-washed and rinsed in ultrapure deionized water prior to the first sample 

collection. Biota samples were collected 

concurrently with bed sediment samples along an 

increasing concentration gradient to prevent 

station-to-station carryover contamination. Nets 

and equipment were thoroughly rinsed in ambient 

stream water at each new mainstem station. New 

nets and depuration chambers were used for the 

tributary stations.

Quality assurance of analytical results for 

biota incluaed laboratory instrument calibration 

with standard solutions and analyses of qualitycontrol samples designed to identify the presence 

and magnitude of bias (M.I. Hornberger, U.S. 

Geological Survey, written commun., 1994). 

Quality-control samples consisted of standard 

reference material and procedural blanks. Each 

type of sample was analyzed in a proportion 

equivalent to about 10 to 20 percent of the total 

number of biota samples.

Recovery efficiency for trace-element 

analyses of standard reference material for biota is 

summarized in table 22. The reference material 

tested was oyster tissue. Data-quality objectives 

have not been established for analytical recovery 

in biota, but mean recoveries were within 11 

percent of complete recovery for all trace 

elements, with me exception of lead (mean 

recovery within 21 percent). A low bias is 

indicated for iron, lead, manganese, and zinc 

(confidence interval does not include 100 percent). 

The cause of this minor bias is unknown, but no 

adjustments to insect data were warranted.

Results of trace-element analyses of 

procedural blanks for biota are in table 23. 

Procedural blanks for biota consisted of the same 

reagents used to digest and reconstitute tissue of 

aquatic insects. The blanks were analyzed 

undiluted at a proportion of one blank per site. No 

adjustments for procedural blanks were necessary 

because all blanks had concentrations less than 10

percent of ambient solid-phase trace-element 

concentrations in insects.

STATISTICAL SUMMARIES OF DATA

Statistical summaries of water-quality, bedsediment, and biological data are provided in 

tables 24-27 for the period of record at each station 

since 1985. The summaries include the period of 

record, number of samples, range, mean, and 

median of concentrations.

Statistical summaries of water-quality data 

(table 24) are based on results of samples collected 

periodically during the station's period of record. 

Statistical summaries of bed-sediment (table 25 

and 26) and biological data (table 27) are based on 

results of samples collected once-annually during 

the indicated years. Because not all stations were 

sampled for bed sediment and biota every year, 

these data may not represent a consecutive annual 

record. Also, because Hydropsyche insects were 

not sorted to the species level during 1986-89, 

statistics for stations sampled during those years 

are based on the results of all Hydropsyche species 

combined. At some sites, statistics for the 

Hydropsvche morosa group are based on the 

combined results for two or more species.

Sample sizes and statistics for bed sediment 

are based on the annual mean concentrations 

determined from the combined results of 

composite samples for a given year. Sample sizes 

and statistics for biological samples are based on 

the results for each individual composite sample 

collected in individual years rather than the annual 

mean concentration in order to describe the full 

range of variability in trace-element assimilation 

among species and to indicate the differences in 

species abundance. The abundance of biological 

taxa at a particular site in a given year may result 

in different taxa analyzed between years or in 

limited biomass which can affect analytical 

detection limits. Where minimum reporting levels 

vary between years, statistical summaries are 

provided only as a general indication of the range 

of detection.

SELECTED REFERENCES

Axtmann, E.V., and Luoma, S.N., 1991, Large 

scale distribution of metal contamination m 

the fine-grained sediment of the Clark Fork 

River, Montana: Applied Geochemistry, v. 6, 

p. 75-88.

Cain, D.J., Luoma, S.N., Carter, J.L., and Ferd, 

S. V, 1992, Aquatic insects as bioindicators of 

trace element contamination in cobble-bottom 

rivers and streams: Canadian Journal of 

Fisheries and Aquatic Sciences, v. 49, no. 10, 

p. 2,141-2,154.

12 Water-Quality, Bed-Sediment, and Biological Data (October 1993 through September 1994) and Statistical Summaries of Data 

for Streams in the Upper Clark Fork Basin, Montana.
Edwards, T.K., and Glysson, G.D., eds., 1988, 

Field methods for measurement of fluvial 

sediment: U.S. Geological Survey Open-File 

Report 86-531,118 p.

Fishman, M.J., 1993, Methods of analysis by the 

U.S. Geological Survey National Water 

Quality Laboratory Determination of 

inorganic and organic constituents in water 

and fluvial sediments: U.S. Geological 

Survey Open-File Report 93-125, 217 p.

Fishman, M.J., and Friedman, L.C., 1989, 

Methods for determination of inorganic 

substances in water and fluvial sediments: 

U.S. Geological Survey Techniques of WaterResources Investigations, Book 5, Chap. Al, 

709 p.

Friedman, L.C., and Erdman, D.E., 1982, Quality 

assurance practices for the chemical and 

biological analyses of water and fluvial 

sediments: U.S. Geological Survey 

Techniques of Water-Resources Investigations, Book 5, Chap. A6, 181 p.

Guy, H.R, 1969, Laboratory theory and methods 

for sediment analysis: U.S. Geological 

Survey Techniques of Water-Resources 

Investigations, Book 5, Chap. Cl, 58 p.

Guy, H.R, and Norman, V.W., 1970, Field 

methods for measurement of fluvial sediment: 

U.S. Geological Survey Techniques of WaterResources Investigations, Book 5, Chap. Cl, 

58 p.

Helsel, D.R., and Cohn, T.A., 1988, Estimation of 

descriptive statistics for multiply censored 

water quality data: Water Resources 

Research, v. 24, no. 12, p. 1,997-2,004.

Horowitz, A.J., Demas, C.R., Fitzgerald, K.K., 

Miller, T.L., and Rickert, D.A., 1994, U.S. 

Geological Survey protocol for trie collection 

and processing 01 surface-water samples for 

the subsequent determination of inorganic 

constituents in filtered water: U.S. Geological 

Survey Open-File Report 94-539, 57 p.

Jones, B.E., 1987, Quality control manual of the 

U.S. Geological Survey's National Water 

Quality Laboratory: U.S. Geological Survey 

Open-File Report 87-457, 17 p.

Knapton, J.R., 1985, Field guidelines for 

collection, treatment, and analysis of water 

samples, Montana District: U.S. Geological 

Survey Open-File Report 85-409, 86 p.

Knapton, J.R., and Nimick, D.A., 1991, Quality 

assurance for water-quality activities of the 

U.S. Geological Survey in Montana: U.S. 

Geological Survey Open-File Report 91-216, 

41 p.

Lambing, J.H., 1987, Water-quality data for the 

Clark Fork and selected tributaries from Deer 

Lodge to Milltown, Montana, March 1985 

through June 1986: U.S. Geological Survey 

Open-File Report 87-110,48 p.

____1988, Water-quality data (July 1986 

through September 1987) and statistical 

summaries (March 1985 through September

1987) for the Clark Fork and selected 

tributaries from Deer Lodge to Missoula, 

Montana: U.S. Geological Survey Open-File 

Report 88-308, 55 p.

____1989, Water-quality data (July 1987 

through September 1988) and statistical 

summaries (March 1985 through September

1988) for the Clark Fork and selected 

tributaries from Galen to Missoula, Montana: 

U.S. Geological Survey Open-File Report 89- 

229, 51 p.

____1990, Water-quality data (July 1988 

through September 1989) and statistical 

summaries (March 1985 through September 

1989) for the Clark Fork and selected 

tributaries from Galen to Missoula, Montana: 

U.S. Geological Survey Open-File Report 90- 

168, 68 p.

____1991, Water-quality and transport 

characteristics of suspended sediment and 

trace elements in streamflow of the upper 

Clark Fork basin from Galen to Missoula, 

Montana, 1985-90: U.S. Geological Survey 

Water-Resources Investigations Report 91- 

4139, 73 p.

Lambing, J.H., and Dodge, K.A., 1993, Quality 

assurance for laboratory analysis of 

suspended-sediment samples by the U.S. 

Geological Survey in Montana: U.S. 

Geological Survey Open-File Report 93-131, 

34 p.

Lambing, J.H., Horaberger, M.I., Axtmann, E.V., 

and Pope, D.A., 1994, Water-quality, bedsediment, and biological data (October 1992 

through September 1993) and statistical 

summaries of water-quality data (March 1985 

through September 1993) for streams in the 

upper Clark Fork basin, Montana: U.S. 

Geological Survey Open-File Report 94-375, 

85 p.

Luoma, S.N., and Bryan, G.W., 1981, A statistical 

assessment of me form of trace metals in 

oxidized estuarine sediments employing 

chemical extractants: Science of the Total 

Environment, v. 17, p. 167-196.

SELECTED REFERENCES 13
Maddy, D.V., Lqpp, L.E., Jackson, D.L., Coupe, 

R.H., and Schertz, T.L., 1989, National Water 

Information System user's manual, volume 2, 

chapter 2, Water-quality system: U.S. 

Geological Survey Open-File Report 89-617 

[variously paged].

Porterfield, George, 1972, Computation of fluvialsediment discharge: U.S. Geological Survey 

Techniques of Water-Resources 

Investigations, Book 3, Chap. C3, 66 p.

Pritt, J.W, and Raese, J.W., eds., 1992, Quality 

assurance/quality control manual National 

Water Quality Laboratory: U.S. Geological 

Survey Open-File Report 92-495, 33 p.

Rantz, S.E., and others, 1982, Computation of 

discharge: U.S. Geological Survey WaterSupply Paper 2175 (2 v.), 631 p.

Taylor, J. K., 1987, Quality assurance of chemical 

measurements: Chelsea, Mich., Lewis 

Publishers, 328 p.

Timme, P.J., 1994, National Water Quality 

Laboratory 1994 Services Catalog: U.S. 

Geological Survey Open-File Report 94-304, 

103 p.

U.S. Geological Survey, 1977, National handbook 

of recommendea methods for water-data 

acquisition Chapter 5, Chemical and physical 

quality of water and sediment: 193 p.

Ward, J.R., and Harr, C.A., eds., 1990, Methods 

for collection and processing of surface-water 

and bed-material samples for physical and 

chemical analyses: U.S. Geological Survey 

Open-File Report 90-140, 71 p.

14 Water-Quality, Bed-Sediment, and Biological Data (October 1993 through September 1994) and Statistical Summaries of Data 

for Streams in the Upper Clark Fork Basin, Montana.
DATA

DATA 15
Table 4. Water-quality data for the upper Clark Fork basin, Montana, October 1993 through September 1994

[Abbreviations: fr/s, cubic feet per second; °C, degrees Celsius; E, estimated; pg/L, micrograms per liter; nS/cm, microsiemens per centimeter at 25 °C; 

mg/L, milligrams per liter; mm, millimeter; ton/d, tons per day. Symbols: <, less than minimum reporting level;--, no data

12323230--BLACKTAIL CREEK AT HARRISON AVENUE, AT BUTTE, MONT.

Date

Oct 1993

28...

Febl994

15...

Mar

08...

Apr

11...

25...

May

12...

20...

Jun

13...

Jul

11...

Aug

17...

Stream- Specific 

flow, conductTime instan- ance, 

taneous onsite 

(ft3/s) (uS/cm)

1045

1045

1010

1015

1155

1310

1120

0945

0950

0845

9.3

5.8

6.3

8.5

30

11

20

9.3

7.3

5.7

262

322

292

259

184

214

193

227

283

340

PH, 

onsite (standard 

units)

7.7

7.7

7.6

7.7

7.7

8.0

7.7

7.7

7.7

7.8

Temperature, 

water

5.0

3.0

2.5

4.5

5.5

17.0

7.0

12.5

10.5

9.5

Hardness, 

total 

(mg/L 

as 

CaC03)

110

130

120

100

71

87

80

96

110

140

r ois.ii im Magne- e«Hii«« PotasC8dis"m' dm* **£" sium,

f±M solved J«J«( solved 

(ma/L) (mg/L) (mg/L) (mg/L)

31 7.0 9.8

36 8.7 12

33 8.0 11

30 7.3 10

20 5.0 7.2

25 5.9 7.8

23 5.5 7.8

28 6.4 8.4

32 7.8 11

39 9.7 14

3.3

2.6

4.2

2.7

2.5

2.2

2.6

2.0

2.5

2.8

Alkalinity 

(mg/L as 

CaC03)

90

108

99

89

64

78

70

86

102

117

Date

Oct 1993

28...

Febl994

15...

Mar

08...

Apr

11...

25...

May

12...

20...

Jun

13...

Jul

11...

Aug

17...

Sulfate, dissolved 

(mg/L)

28

36

31

26

18

19

18

19

25

36

Chloride, 

dissolved 

(mg/L)

5.8

8.0

7.5

7.4

4.4

4.1

3.6

4.0

5.3

7.5

Fluoride, 

dissolved 

(mg/L)

0.5

.2

.3

.3

.3

.3

.3

.4

.3

.3

Silica, dissolved 

(mg/L)

23

32

28

24

20

23

24

25

28

28

Solids, 

sum of 

constituents, 

dissolved 

(mg/L)

163

200

183

161

116

134

127

145

173

208

Arsenic, 

total 

recoverable

4

2

4

4

7

8

8

8

6

3

Cad- Cad 

Arsenic, mium, miT, 

dis- total mju.msolved recov- JS^d 

(Mg/L) erable a, °!y,f? (ug/L) iw1-)

3 <1 <0.1

2 <1 <.l

3 <1 <.l

3 <1 <.l

5 <1 <.l

7 <1 <.l

5 <1 <.l

6 <1 <.l

5 <1 <.l

3 <1 <.l

Copper, 

total 

recoverable 

(ug/L)

10

2

6

5

13

7

11

9

5

3

Copper, 

dissolved 

(ug/L)

5

<1

3

3

6

5

7

5

3

1

Date

Oct 1993

28...

Febl994

15...

Mar

08...

Apr

11...

25...

May

12...

20...

Jun

13...

Jul

11...

Aug

17...

Iron, 

total 

recoverable (Mg/L)

660

260

600

550

1,200

700

1,300

650

390

310

iron, dissolved

95

42

170

240

360

240

270

250

150

24

Lead, 

total 

recoverable (Mg/L)

5

<1

1

<1

5

1

3

2

<1

1

Lead, dissolved

0.5

<.5

<.5

<.5

<.5

<.5

<.5

<.5

<.5

<-5

Manganese, 

total 

recoverable

(Mg/L)

70

60

90

50

60

60

60

40

40

100

Manganese, dissolved

(ug/L)

40

52

74

41

34

41

31

26

31

99

Zinc, Zinc, Seditotal dis- ment, 

recov- solved suserable (Mg/L) pended 

(Mg/L) (mg/L)

30 7 14

10 7 4

<10 7 8

<10 6 4

20 4 21

<10 <3 9

10 3 29

10 5 7

<10 <3 3

<10 <3 4

ment discharge, 

suspended 

(ton/d)

0.35

.06

.14

.09

1.7

.27

1.6

.18

.06

.06

Sediment, 

suspended 

(percent 

finer than 

0.062 mm)

95

76

92

84

80

85

70

87

94

87

16 Water-Quality, Bed-Sediment, and Biological Data (October 1993 through September 1994) and Statistical Summaries of Data for 

Streams in the Upper Clark Fork Basin, Montana.
Table 4. Water-quality data for the upper Clark Fork basin, Montana, October 1993 through September 1994 (Continued) 

12323250-SILVER BOW CREEK BELOW BLACKTAIL CREEK, AT BUTTE, MONT.

Date

Oct 1993

28...

Febl994

15...

Mar

08...

Apr

11...

25...

May

12...

20...

Jim

13...

Jul

11...

Aug

17...

Stream- Specific 

flow, conductTime instan- ance, 

taneous onsite 

(ft3/s) (uS/cm)

1215

1200

1130

1205

1400

1115

1030

1105

1110

1015

29

15

19

26

52

28

41

26

22

17

473

510

468

456

315

492

388

451

534

631

PH, 

onsite 

(standard 

units)

7.4

7.5

7.5

7.5

7.5

7.6

7.6

7.5

7.4

7.3

Temperature, 

water (°C)

9.0

1.5

6.0

9.0

7.0

14.0

9.0

8.5

15.0

16.0

Hardness, 

total 

(mg/L 

as 

CaCO3)

160

140

140

140

100

150

120

130

160

160

Calcium, 

dissolved 

(mg/L)

47

41

40

41

30

42

35

37

45

45

Magnesium, 

dissolved 

(mg/L)

11

10

9.8

10

7.1

11

8.7

8.6

11

12

Sodium, 

dissolved 

(mg/L)

20

32

28

25

16

23

18

21

28

34

Potassium, 

dissolved 

(mg/L)

5.9

5.5

6.0

5.3

4.0

17

17

18

20

35

Alkalinity 

(mg/L 

as 

CaC03)

88

95

91

89

66

94

89

94

113

133

Date

Oct 1993

28...

Feb 1994

15...

Mar

08...

Apr

11...

25...

May

12...

20...

Jun

13...

Jul

11...

Aug

17...

Sulfate, 

dissolved 

(mg/L)

87

70

68

75

46

82

58

63

83

96

Chloride, 

dissolved 

(mg/L)

18

28

20

21

13

18

14

19

21

25

Fluoride, 

dissolved 

(mg/L)

0.6

.4

.3

.4

.5

.4

.4

.7

.4

.5

Silica, 

dissolved 

(mg/L)

23

28

26

23

20

22

24

23

24

22

Solids, 

sum of 

constituents, 

dissolved 

(mg/L)

267

273

254

255

177

273

230

248

302

353

Arsenic, 

total 

recoverable 

(H9/L)

18

22

10

11

20

14

15

13

18

10

Arsenic, 

dissolved (HO/L)

9

6

5

8

8

10

8

8

7

6

Cadmium, 

total 

recoverable (ng/L)

3

4

2

2

2

2

2

2

2

6

Cadmium, dissolved (ng/L)

2.8

1.5

1.6

1.4

1.3

1.3

1.3

1.6

2.4

6.2

Copper, 

total 

recoverable 

Uig/L)

250

320

100

100

210

93

140

130

130

85

Copper, 

dissolved kg/L)

120

47

60

54

70

53

75

67

93

47

Date

Oct 1993

28...

Feb 1994

15...

Mar

08...

Apr

11...

25...

May

12...

20...

Jun

13...

Jul

11...

Aug

17...

Iron, 

total 

recoverable 

(H9/L)

1,400

2,000

760

600

2,300

700

1,200

880

640

310

Iron, 

dissolved (ng/L)

87

120

170

84

120

110

220

110

75

54

Lead, 

total 

recoverable (ng/L)

31

42

10

4

62

6

12

18

4

7

Lead, 

dissolved

(H9/L)

1.0

.8

1.0

<.5

1.9

.5

1.1

.6

<.5

<.5

Manganese, 

total 

recoverable 

(HO/L)

830

660

590

730

670

660

540

680

940

1,600

Manganese, 

dissolved 

(ng/L)

810

580

590

690

500

630

490

630

880

1,700

Zinc, 

total 

recoverable (ng/L)

1,100

940

730

550

700

650

570

660

900

2,200

Zinc, 

dissolved (ng/L)

1,000

590

610

490

460

540

460

550

810

2,200

Sediment, 

suspended 

(mg/L)

29

37

16

6

49

8

19

17

6

3

Sediment 

discharge, 

suspended 

(ton/d)

2.3

1.5

.82

.42

6.9

.60

2.1

1.2

.36

.14

Sediment, 

suspended 

(percent 

finer than 

0.062 mm)

85

71

86

93

93

87

85

91

86

91

TABLE 4 17
Table 4. Water-quality data for the upper Clark Fork basin, Montana, October 1993 through September 1994 (Continued)

12323600-SILVER BOW CREEK AT OPPORTUNITY, MONT.

Date

Oct 1993

28...

Febl994

18...

Mar

08...

Apr

11...

25...

May

12...

20...

Jun

13...

Jul

05...

11...

Aug

17...

Stream- Specific 

flow, conductTime instan- ance, 

taneous onsite 

(fr/s) (uS7cm)

1325

0900

1255

1315

1525

0955

0845

1255

2130

1240

1145

52

E47

37

58

133

107

143

52

51

56

26

407

444

444

383

270

272

299

359

593

368

509

PH, 

onsfte 

(standard 

units)

8.7

7.9

8.1

8.7

8.1

8.2

7.9

8.6

7.2

8.3

8.7

Temperature, 

water

4.0

0.0

5.0

10.0

4.5

11.0

6.0

13.5

13.0

17.0

16.5

Hardness, 

total 

(mg/L 

as 

CsC03)

150

150

150

140

100

100

110

130

200

130

170

Calcium, 

dissolved 

(mg/L)

44

45

45

41

31

31

34

39

54

40

50

Magnesium, 

dissolved 

(mg/L)

9.8

9.5

9.8

9.1

6.3

6.0

6.8

8.1

15

8.4

12

Sodium, 

dissolved 

(mg/L)

20

25

22

19

11

10

13

15

20

16

26

Potassium, 

dissolved 

(mg/L)

4.2

4.3

5.4

4.1

3.1

4.0

6.8

8.1

8.6

8.8

16

Alksffnfty 

(mg/L 

ss 

CaC03)

99

100

101

98

74

79

82

99

60

101

117

Date

Oct 1993

28...

Febl994

18...

Mar

08...

Apr

11...

25...

May

12...

20...

Jun

13...

Jul

05...

11...

Aug

17...

Sulfate, 

dissolved 

(mg/L)

76

80

77

68

43

38

48

59

190

61

100

Chloride, 

dissolved 

(mg/L)

12

19

15

12

6.7

6.4

7.1

10

12

11

18

Ffuoride, 

dissolved 

(mg/L)

.5

.6

.5

.4

.3

.2

.4

.4

.8

.4

.6

Silica, 

dissolved 

(mg/L)

25

28

26

23

21

18

21

20

15

21

21

Solids, 

sum of 

constituents, 

dissolved 

(mg/L)

252

273

262

236

168

161

187

220

374

228

315

Arsenic, 

total 

recoverable

12

14

18

19

24

15

29

16

170

15

13

Arsenic, 

dissolved

7

8

10

9

10

7

11

8

1

7

11

Cadmium, 

totsl 

recoverable 

(Mg/L)

2

3

2

2

2

<1

2

1

49

1

1

Csdmium, 

dissolved

1.4

2.3

1.5

.9

1.1

.5

1.1

.9

41

1.1

.8

Copper, 

total 

recoverable

140

120

140

140

210

79

220

140

3,900

96

85

Copper, 

dissolved

51

60

60

47

70

28

75

57

450

48

35

Date

Oct 1993

28...

Febl994

19...

Mar

08...

Apr

11...

25...

May

12...

20...

Jun

13...

Jul

05...

11...

Aug

17...

Iron, 

total 

recoverable

640

490

860

830

1,700

770

1,900

660

8,600

610

290

Iron, 

dissolved

37

25

30

33

150

46

110

44

<3

30

14

Lead, 

total 

recoverable

12

10

18

17

36

11

41

10

260

13

7

Lead, 

dissolved

.7

.6

.7

<5

1.2

<5

.7

<5

<.5

<.5

<.5

Msngsnese, 

total 

recoverable (ng/

480

680

630

600

540

330

620

490

10,000

680

580

Manganese, 

dissolved

470

700

620

510

440

270

500

440

9,300

630

590

Zinc, 

total 

recoverable (ng/L)

590

680

520

410

480

230

580

360

15,000

370

260

Zinc, 

dissolved

(ng/D

440

580

380

170

310

110

320

160

13,000

200

140

Sediment, 

suspended 

(mg/L)

12

6

12

14

37

21

51

10

183

10

6

Qerii. 9CIJImerit 

dfschsrge, 

suspended

(ton/d)

1.7

.76

1.2

2.2

13

6.1

20

1.4

25

1.5

.42

Sediment, 

suspended 

(percent 

finer than 

0.062 mm)

85

61

87

80

67

72

60

61

91

85

88

18 Water-Quality, Bed-Sediment, and Biological Data (October 1993 through September 1994) and Statistical Summaries of Data for 

Streams in the Upper Clark Fork Basin, Montana.
Table 4. Water-quality data for the upper Clark Fork basin, Montana, October 1993 through September 1994 (Continued)

12323750-SILVER BOW CREEK AT WARM SPRINGS. MONT.

Date

Oct 1993

28...

Febl994

15...

Mar

08...

Apr

11...

25...

May

12...

20...

25...

Jun

13...

Jul

11...

Aug

17...

Time

1420

1350

1440

1515

1630

0800

0800

1430

1410

1350

1355

Stream- Specific 

flow, conductinstan- ance, 

taneous onsrte 

(ft3/s) (uS/cm)

77

51

84

94

183

181

El 82

181

88

88

24

545

614

526

477

429

397

365

436

433

585

PH, 

onsite (standard 

units)

8.7

8.9

9.2

8.9

8.7

8.9

8.8

8.8

8.7

9.2

Temperature, 

water

5.5

4.0

5.5

9.0

11.0

16.0

_.

17.0

17.0

20.0

22.0

Hardness, 

total 

(mg/L 

as 

CaCO3)

240

260

220

200

170

160

160

190

180

260

Calcium, dissolved 

(mg/L)

71

78

63

57

47

47

..

47

58

54

74

Magnesium, dissolved 

(mg/L)

15

17

15

14

12

11

..

9.5

12

12

19

*°*l»m' s"mS;

?±T! solved 

<m9/L> (mg/L)

17 5.5

21 4.6

19 3.9

19 4.3

18 4.1

15 3.8

13 4.3

13 4.0

14 4.6

18 5.6

Alkalinity 

(mg/L 

as 

CaCO3)

112

120

107

84

91

96

100

109

101

81

Date

Oct 1993

28...

Febl994

15...

Mar

08...

Apr

11...

25...

May

12...

20...

25...

Jun

13...

Jul

11...

Aug

17...

Suifate, dissolved 

(mg/L)

150

180

140

140

110

86

75

100

110

210

Chloride, dissolved 

(mg/L)

7.6

1.3

11

11

10

7.4

6.2

5.6

6.5

7.6

Fiuoride, dissolved 

(mg/L)

.8

1.0

.8

.9

.7

.6

..

.5

.7

.8

1.2

Silica, dissolved 

(mg/L)

8.6

20

16

12

16

12

..

11

9.5

11

12

Solids, 

sum of 

constituents, 

dissolved 

(mg/L)

343

395

333

309

273

241

Ill

268

274

3%

Arsenic, 

total 

recoverable

20

14

12

13

20

25

27

22

19

27

Arsenic, dissolved 

(Mg/L)

16

10

10

11

17

19

25

21

19

27

Cadmium, 

total 

recoverable 

(Mg/L)

<1

<l

<1

<1

<l

<1

_

<1

<1

<1

<1

Cad- Copper, 

mium, total 

dls- recovsolved erable 

(ng/L) (ng/L)

<.l 23

.1 21

.1 25

<.l 21

<.l 35

<.l 34

_

.1 20

<1 19

<1 15

<.l 10

Copper, dissolved 

(ug/L)

11

10

12

10

10

15

_

17

15

11

8

Date

Oct 1993

28...

Febl994

15...

Mar

OSApr

11...

25...

May

12...

20...

25...

Jun

13...

Jul

11...

Aug

17...

Iron, 

total 

recoverable

660

630

490

340

610

590

180

180

200

130

Iron, dissolved 

(Mg/L)

20

5

8

10

19

12

10

6

5

3

Lead, 

total 

recoverable 

(Mg/L)

2

<1

1

1

3

4

<1

<1

<1

1

Lead, dissolved (Mg/L)

<.5

<5

<5

<5

<.5

<5

<.5

<.5

<.5

<5

Manganese, 

total 

recoverable (Mg/L)

200

570

350

240

340

220

90

90

90

80

Manganese, dissolved 

(Mg/L)

130

500

250

75

170

92

-

52

40

36

34

Zinc, 

total 

recoverable 

(Mg/L)

70

100

100

60

170

180

..

30

20

30

20

Zinc, dissolved

(Mg/D

16

23

11

9

10

4

4

<3

6

3

SaHI. wUUI

Sedi- men! 

merit, dissus- charge, 

pended sus- 

(mg/L) pended 

(ton/d)

E4 .83

6 .83

8 1.8

7 1.8

22 11

16 7.8

22 11

2 .98

3 .71

2 .48

4 .26

Sediment, 

suspended 

(percent 

finer than 

0.062 mm)

-

79

85

83

69

67

70

80

88

94

88

TABLE 4 19
Table 4. Water-quality data for the upper Clark Fork basin, Montana, October 1993 through September 1994 (Continued)

12323770--WARM SPRINGS CREEK AT WARM SPRINGS, MONT.

Date

Oct 1993

28...

Feb 1994

16...

Apr

25...

May

12...

25...

Aug

17...

Time

1515

0820

1805

0905

1340

1245

Stream- Specific 

flow, conductinstan- ance, 

taneous onsite 

(fr/s) (nS/cm)

77

E47

99

202

92

2.8

316

399

262

180

255

795

PH, 

onsite 

(standard 

units)

8.5

7.8

8.3

8.0

8.2

8.3

Temperature, 

water

4.0

.5

5.0

9.0

13.0

16.0

Hardness, 

total 

(mg/L 

as 

CaC03)

160

190

130

83

120

420

Calcium, 

dissolved 

(mg/L)

49

58

39

26

38

130

Magnesium, 

dissolved 

(mg/L)

9.5

12

7.3

4.4

6.9

22

s<£m' -2T

dis- j,_

enluoH «'S"

fm^n solved 

IWV (mg/L)

3.5 1.4

4.2 1.7

2.7 1.1

1.8 .9

2.7 1.3

7.4 2.5

Alkalinity 

(mg/L 

as 

CaC03)

120

132

98

68

91

146

Date

Oct 1993

28...

Feb 1994

16...

Apr

25...

May

12...

29...

Aug

17...

Sulfate, 

dissolved 

(mg/L)

43

69

35

20

35

270

Chloride, 

dissolved 

(mg/L)

1.0

1.3

.9

.5

1.0

3.2

Fiuoride, dissolved 

(mg/L)

.4

.4

.3

.3

.4

.6

Silica, 

dissolved 

(mg/L)

12

13

10

8.7

10

12

Solids, 

sum of 

constituents, 

dissolved 

(mg/L)

192

239

155

103

150

536

Arsenic, 

total 

recoverable

4

5

7

13

6

6

Arsenic, 

dissolved 

(H9/L)

3

4

4

4

3

7

Cadmium, 

total 

recoverable 

(H9/L)

<1

<l

<1

<1

<l

<1

Cad- Copper, 

mium, total 

dis- recovsolved erable 

(MQ/L) (ng/L)

<1 5

<.l 7

<.l 32

<.l 72

<.l 14

<1 4

Copper, 

dissolved

2

2

3

4

3

2

Date

Oct 1993

28...

Feb 1994

16...

Apr

25...

May

12...

29...

Aug

17...

iron, 

total 

recoverable

120

110

590

1,400

230

40

iron, 

dissolved 

(H9/L)

12

8

10

14

6

5

Lead, 

total 

recoverable 

(H9/L)

<1

<1

5

9

1

<1

Lead, 

dissolved

<5

<.5

<.5

<5

<.5

<5

Manganese, 

total 

recoverable

(H9/ '

120

170

200

400

230

540

Manganese, 

dissolved 

(H9/L)

110

120

81

94

170

570

Zinc, 

total 

recoverable

10

<10

20

40

10

<10

Zinc, 

dissolved 

(H9/L)

4

7

<3

<3

<3

<3

QaHi oeoSedi- ment 

ment, dissus- charge, 

pended sus- 

(mg/L) pended

Xton/d)

4 .83

6 .76

31 8.3

90 49

12 3.0

18 .14

Sediment, 

suspended 

{percent 

finer than 

0.062 mm)

77

63

72

57

66

83

20 Water-Quality, Bed-Sediment, and Biological Data (October 1993 through September 1994) and Statistical Summaries of Data for 

Streams in the Upper Clark Fork Basin, Montana.
Table 4. Water-quality data for the upper Clark Fork basin, Montana, October 1993 through September 1994 (Continued)

12323800-CLARK FORK NEAR GALEN, MONT.

Date

Oct 1993

28...

Febl994

15...

Mar

08...

Apr

11...

26...

May

12...

25...

Jun

13...

Jul

11...

Aug

17...

Stream- Specific 

flow, conductTime instan- ance, 

taneous onsfte 

(ft3/s) (uS/cm)

1615

1445

1600

1640

0820

0645

1255

1555

1545

1525

155

85

117

136

290

375

278

138

106

22

442

536

501

469

394

304

343

423

427

635

PH, 

onsite 

(standard 

units)

8.9

8.6

8.9

8.7

8.3

8.5

8.7

8.6

8.8

8.8

Temperature, 

water (°C)

5.0

3.0

6.0

11.0

6.0

13.0

15.5

15.0

22.0

21.0

Hardness, 

total 

(mg/L 

as 

CaC03)

200

240

220

210

160

130

150

190

190

290

Calcium, dissolved 

(mg/L)

62

71

63

59

47

38

46

57

57

84

Magnesium, dissolved 

(mg/L)

12

15

14

14

11

7.7

9.0

11

12

19

Sodium, dissolved 

(mg/L)

3.6

14

15

14

13

8.5

9.9

11

13

18

Potassium, dissolved 

(mg/L)

3.4

3.3

3.3

3.3

3.2

2.3

3.6

3.1

4.3

5.3

Alkalinity 

(mg/L 

as 

CaCO3)

116

130

118

102

97

84

98

110

105

100

Date

Oct 1993

28...

Febl994

15...

Mar

08...

Apr

11...

26...

May

12...

25...

Jun

13...

Jul

11...

Aug

17...

Sulfate, dissolved 

(mg/L)

100

130

120

120

88

56

65

96

110

220

Chloride, dissolved 

(mg/L)

4.8

7.7

8.2

8.5

6.9

4.2

4.6

5.1

5.9

8.2

Fluoride, dissolved 

(mg/L)

.6

.8

.7

.7

.6

.5

.5

.6

.7

1.1

Silica, dissolved 

(mg/L)

9.7

17

15

12

14

11

11

10

11

12

Solids, 

sum of 

constituents, 

dissolved 

(mg/L)

266

337

310

293

242

179

208

260

277

428

Arsenic, 

total 

recoverable (ng/L)

12

10

11

10

16

20

20

16

18

23

Arsenic, dissolved 

(ng/L)

11

8

8

7

12

12

18

14

17

25

Cadmium, 

total 

recoverable (ng/L)

<1

<1

<1

<1

<1

<1

<1

<1

<1

<1

Cadmium, dissolved (ng/L)

<l

.1

.2

<.l

<1

<1

<.]

<1

<.!

<.l

Copper, 

total 

recoverable <«J/L)

12

19

21

20

35

65

24

17

15

10

Copper, dissolved (ng/L)

7

7

9

8

7

9

12

10

10

8

Date

Oct 1993

28...

Febl994

15...

Mar

08...

Apr

11...

26...

May

12...

25...

Jun

13...

Jul

11...

Aug

17...

Iron, 

total 

recoverable (ng/L)

170

400

400

330

580

1,200

320

190

150

100

Iron, 

dissolved 

<ng/L)

8

4

7

6

23

14

8

6

6

20

Lead, 

total 

recoverable <ng/L)

<1

<1

1

2

3

7

1

<1

<1

<1

Lead, 

dissolved <ng/L)

<5

<5

<5

<.5

<.5

<5

<5

<5

<5

<5

Manganese, 

total 

recoverable 

(ng/L)

120

340

300

260

330

410

180

180

100

80

Manganese, dissolved <ng/L)

100

260

210

95

160

81

93

120

46

46

Zinc, 

total 

recoverable <ng/L)

30

60

70

50

100

110

40

20

20

10

Zinc, dissolved (ng/L)

5

17

13

9

10

<3

6

5

26

6

Sediment, 

suspended 

<mg/L)

4

5

7

9

18

47

11

6

3

2

Sediment discharge, 

suspended 

(ton/d)

1.7

1.1

2.2

3.3

14

48

8.3

2.2

.86

.12

Sediment, 

suspended 

(percent 

finer than 

0.062 mm)

80

86

80

80

75

73

71

74

88

89

TABLE 4 21
Table 4. Water-quality data for the upper Clark Fork basin, Montana, October 1993 through September 1994 (Continued)

12324200-CLARK FORK AT DEER LODGE, MONT.

Date

Oct 1993

28...

Febl994

15...

Mar

08...

Apr

12...

26...

May

11...

25...

Jun

13...

Jul

11...

Aug

17...

Time

1740

1610

1715

0735

0930

1720

1120

1710

1825

1645

Stream- Specific 

flow, conductinstan- ance, 

taneous onsite 

(ft3/s) (uS/cm)

292

219

247

247

408

390

297

168

133

27

489

498

515

487

441

355

406

461

478

524

PH, 

onsite (standard 

units)

8.6

8.2

8.4

8.2

8.2

8.4

8.2

8.5

8.5

8.4

Temperature, 

water

5.0

1.0

5.0

7.0

5.0

17.0

14.0

14.5

22.0

21.0

Hardness, 

total 

(mg/L 

as 

CaC03)

230

220

230

240

190

150

180

210

210

220

Calcium, ISKT" _i- slum, dis- j|_

onluaH dls~ 

?mn^ S°IVed

<m9/L> (mg/L)

68 14

67 14

66 15

71 16

54 13

45 9.6

53 11

61 13

62 13

64 14

s<sr- *sr dis- j|_ '

solved J 8- in~n \ solved

C^* (mg/L)

14 3.7

14 3.0

16 3.1

17 3.6

14 3.2

11 2.7

13 4.1

14 3.3

16 4.1

25 4.9

Alkalinity 

(mg/L 

as 

CaCO3)

149

148

144

146

119

102

121

142

141

182

Date

Oct 1993

28...

Febl994

15...

Mar

08...

Apr

12...

26...

May

11...

25...

Jun

13...

Jul

11...

Aug

17...

Sulfate, dissolved 

(mg/L)

98

100

110

120

92

67

75

86

98

75

Chloride, dissolved 

(mg/L)

6.3

6.3

7.5

8.4

7.1

5.0

5.8

6.5

7.2

12

Fluo 

ride, dissolved 

(mg/L)

.7

.7

.7

.7

.6

.5

.6

.6

.7

.1

Silica, dissolved 

(mg/L)

15

21

19

17

17

13

16

16

17

34

Solids, 

sum of 

constituents, 

dissolved 

(mg/L)

309

315

324

341

272

215

251

286

303

338

Arsenic, 

total 

recoverable (MO/L)

11

13

13

18

23

25

23

14

17

12

CadArsenic, mlum, 

dis- total 

solved recov- 

(ng/L) erable

10 <l

7 <1

9 <1

11 <1

13 <1

15 <1

17 <1

13 <1

15 <1

13 <1

Cad- Copper, 

mium, total 

dis- recovsolved erable 

fog/L) (ug/L)

<1 15

<.l 43

<.l 40

<.l 71

<.l 92

<.l 93

<.l 51

<.l 19

<1 25

<.l 11

Copper, dissolved (ug/L)

6

5

7

7

8

11

11

9

13

7

Date

Oct 1993

28...

Febl994

15...

Mar

08...

Apr

12...

26...

May

11...

25...

Jun

13...

Jul

11...

Aug

17...

Iron, 

total 

recoverable 

(Mg/L)

210

730

710

910

1,400

1,400

700

250

240

70

Iron, dissolved 

(Mg/L)

4

6

9

10

13

10

9

5

5

9

Lead, 

total 

recoverable

1

5

4

7

10

11

5

2

2

1

Lead, dissolved

<5

<5

<.5

<5

<5

<5

<5

<.5

<5

<5

Manganese, 

total 

recoverable

40

160

180

250

310

300

180

80

90

50

Manganese, dissolved 

(Mg/L)

32

56

71

54

30

22

31

46

28

27

Zinc, 7I_. 

rl?ov 5f

S3. ffl? (ug/L) <U8/L>

30 10

60 17

60 17

80 19

120 16

120 5

60 11

30 5

30 8

10 6

Sarii. wVXJI

Sedi- merit 

merit, dissus- charge, 

pended sus- 

(mg/L) pended

(ton/d)

8 6.3

32 19

28 19

37 25

66 73

57 60

24 19

10 4.5

10 3.6

8 .58

Sediment, 

suspended 

(percent 

finer than 

0.062 mm)

65

71

70

78

53

68

79

80

87

90

22 Water-Quality, Bed-Sediment, and Biological Data (October 1993 through September 1994) and Statistical Summaries of Data for 

Streams in the Upper Clark Fork Basin, Montana.
Table 4. Water-quality data for the upper Clark Fork basin, Montana, October 1993 through September 1994 (Continued)

12324590--LITTLE BLACKFOOT RIVER NEAR GARRISON, MONT.

Date

Oct 1993

29...

Febl994

15...

Apr

26...

May

11...

25...

Aug

17...

Stream- Specific 

flow, conductTime ins tan- ance, 

taneous onsita 

(frVs) (nS/cm)

1315

1725

1135

1550

0955

1820

99

E60

645

387

283

21

245

256

155

165

206

293

PH. 

onsite 

(standard 

units)

8.3

8.0

8.0

8.1

8.1

8.5

Temperature, 

water

1.5

.5

2.5

14.0

10.5

22.0

Hardness, 

total 

(mg/L 

as 

CaCO3)

110

120

73

73

94

140

Calcium, 

dissolved 

(mg/L)

32

35

21

21

27

40

Magnesium, 

dissolved 

(mg/L)

7.7

8.0

5.0

5.1

6.5

9.4

s<£m' -Sf

dis 

f±«j solved ( "a"-) (mg/L)

5.3 1.7

5.5 1.8

3.7 1.3

3.6 1.3

4.9 2.0

7.3 2.4

Alkalinity 

(mg/L 

as 

CaCO3)

114

122

68

72

92

141

Date

Oct 1993

29...

Febl994

15...

Apr

26...

May

11...

25...

Aug

17...

Sulfate, 

dissolved 

(mg/L)

14

14

10

9.8

13

14

Chloride, 

dissolved 

(mg/L)

1.3

1.5

1.0

.8

1.1

1.6

Fiuoride, 

dissolved 

(mg/L)

.2

.2

.1

.2

.1

.2

Silica, 

dissolved 

(mg/L)

21

22

17

18

20

23

Solids, 

sum of 

constituents, 

dissolved 

(mg/L)

152

161

100

103

130

182

Arsenic, 

total 

recoverable

6

5

6

6

7

7

Arsenic, 

dissolved

5

4

4

5

5

7

Cadmium, 

total 

recoverable (ng/L)

<i

<i

<i

<i

<i

<i

Cad- Copper, 

mium, total 

dis- recovsolved erabie

0.2 <1

<.l <1

<.l 3

.1 2

<.l 2

<.l 1

solved

<l

<1

l

2

1

<1

Date

Oct 1993

29...

Febl994

15...

Apr

26...

May

11...

25...

Aug

17...

Iron, 

total 

recoverable

110

60

920

360

230

60

iron, 

dissolved

(ng/L)

8

5

69

37

22

6

Lead, 

total 

recoverable

<1

<1

2

1

<1

<1

Lead, 

dissolved

<5

<5

<5

<.5

<5

<5

Manganese, 

total 

recoverable

(US' )

<10

<10

60

30

30

20

Manganese, 

dissolved

4

6

8

9

10

13

Zinc, 

total 

recoverable (ng/L)

<10

<10

10

<10

<10

<10

Zinc, 

dissolved

4

3

4

<3

<3

<3

CaHi. wOUl

Sedi- ment 

ment, dissus- charge, 

pended sus- 

(mg/L) pended

(ton/d)

2 .53

2 .32

40 70

15 16

17 13

3 .17

Sediment, 

suspended 

(percent 

finer than 

0.062 mm)

83

84

56

67

79

86

TABLE 4 23
Table 4. Water-quality data for the upper Clark Fork basin, Montana, October 1993 through September 1994 (Continued)

12324680--CLARK FORK AT GOLDCREEK, MONT.

Date

Oct 1993

29...

Febl994

16...

Mar

09...

Apr

12...

26...

May

11...

25...

Jun

13...

Jul

12...

Aug

17...

Time

1215

1045

0830

0945

1330

1410

0855

1840

0730

1935

Stream- Specific 

flow, conductinstan- ance, 

taneous onsite 

(ft3/s) (uS/cm)

529

E380

403

505

1,130

816

721

464

285

87

422

437

436

419

284

283

337

381

411

450

pH-i 

onsite (standard 

units)

8.4

8.2

8.3

8.3

8.2

8.3

8.2

8.5

8.2

8.6

Temperature, 

water (°C)

2.0

0.0

1.0

7.0

4.5

14.0

12.5

14.0

14.0

20.0

Hardness, 

total 

(mg/L

CaC03)

190

200

190

190

120

120

150

170

180

190

Calcium, 

dissolved 

(mg/L)

56

59

57

55

36

36

44

50

54

56

Magnesium, 

dissolved 

(mg/L)

12

12

12

13

8.3

7.8

9.4

11

11

13

Sodium, 

dissolved 

(mg/L)

12

12

12

13

8.3

7.9

10

11

12

19

Potassium, 

dissolved 

(mg/L)

3.2

2.8

3.1

2.9

2.1

2.2

3.3

2.6

3.1

4.1

Alkalinity 

(mg/L 

as 

CaCO3)

147

114

140

132

95

95

121

148

157

172

Date

Oct 1993

29...

Febl994

16...

Mar

09...

Apr

12...

26...

May

11...

25...

Jun

13...

Jul

12...

Aug

17...

Sulfate, 

dissolved 

(mg/L)

68

80

77

75

43

40

45

48

52

58

Chloride, 

dissolved 

(mg/L)

4.6

5.2

5.7

5.6

3.5

3.1

3.7

3.8

4.4

7.2

Fluoride, 

dissolved 

(mg/L)

.5

.6

.5

.5

.3

.3

.4

.4

.5

.6

Silica, 

dissolved 

(mg/L)

18

22

19

18

18

16

19

21

22

25

Solids, 

sum of 

constituents, 

dissolved 

(mg/L)

262

262

270

264

177

170

207

237

253

286

Arsenic, 

total 

recoverable

(ng/L)

8

9

10

13

14

16

15

10

12

14

Arsenic, 

dissolved

(ug/L)

7

6

7

8

8

10

11

10

10

15

Cadmium, 

total 

recoverable 

(ug/L)

<i

<i

<i

<i

<i

<i

<i

<i

<i

<i

Cadmium, 

dissolved

(ug/M

<.i

<.i

<i

<i

<.i

<.i

<.i

<.i

<.i

<.i

Copper, 

total 

recoverable 

(ug/L)

13

15

33

49

49

63

26

13

23

8

Copper, 

dissolved

(ng/M

4

4

5

6

6

7

7

5

7

6

Date

Oct 1993

29...

Febl994

16...

Mar

09...

Apr

12...

26...

May

11...

25...

Jun

13...

Jul

12...

Aug

17...

Iron, 

total 

recoverable

(ng/U

230

260

630

890

1,700

1,200

540

200

410

60

Iron, 

dissolved (ng/L)

4

7

12

14

43

16

11

8

6

5

Lead, 

total 

recoverable

(ug/L)

i

2

4

6

9

8

3

1

2

<1

Lead, 

dissolved 

(ng/L)

<5

<.5

<5

<5

<5

<5

<5

<5

<.5

<5

Manganese, 

total 

recoverable

(ug/L)

50

60

100

160

230

190

100

60

130

30

Manganese, 

dissolved (ug/L)

20

23

26

22

14

15

15

20

19

11

Zinc, 

total 

recoverable (ng/L)

30

30

50

70

90

80

40

20

30

10

Zinc, 

dissolved (ng/L)

9

12

14

9

9

<3

4

<3

6

3

Sediment, 

suspended 

(mg/L)

6

10

22

39

74

52

23

10

17

4

Sediment 

discharge, 

suspended 

(ton/d)

8.6

10

24

53

226

115

45

13

13

.94

Sediment, 

suspended 

(percent 

finer than 

0.062 mm)

90

74

82

77

52

70

82

82

88

89

24 Water-Quality, Bed-Sediment, and Biological Data (October 1993 through September 1994) and Statistical Summaries of Data for 

Streams In the Upper Clark Fork Basin, Montana.
Table 4. Water-quality data for the upper Clark Fork basin, Montana, October 1993 through September 1994 (Continued)

12331500--FLINT CREEK NEAR DRUMMOND, MONT.

Date

Oct 1993

29...

Febl994

16...

Mar

09...

Apr

12...

27...

May

11...

25...

Jun

14...

Jul

12...

Aug

18...

Time

1045

1150

1000

1110

0945

1300

0715

1650

0905

1630

Stream- Specific 

flow, conductinstan- ance, 

taneous onslte 

(ft3/s) (uS/cm)

151

E120

105

130

288

197

63

205

80

15

312

286

294

284

196

177

338

330

393

507

PH, 

onsite 

(standard 

units)

8.3

8.4

8.4

8.6

8.2

8.2

8.2

8.3

8.2

8.5

Temperature, 

water

1.0

0.0

1.0

6.0

2.5

12.5

10.0

11.0

12.0

21.0

Hardness, 

total 

(mg/L 

as 

CaCO3)

150

140

140

140

90

79

160

150

180

240

Calcium, 

dissolved 

(mg/L)

39

36

36

36

24

22

44

41

50

65

Magnesium, 

dissolved 

(mg/L)

12

11

11

11

7.2

5.9

13

12

14

19

Sodium, 

dissolved 

(mg/L)

7.8

6.3

6.0

6.8

5.0

3.8

7.7

8.2

9.2

15

Potassium, 

dissolved 

(mg/L)

2.9

2.2

2.7

2.5

1.0

1.5

4.3

2.9

3.7

6.2

Alkalinity 

(mg/L

CaC03)

147

140

139

134

87

79

158

159

191

237

Date

Oct 1993

29...

Febl994

16...

Mar

09...

Apr

12...

27...

May

11...

25...

Jun

14...

Jul

12...

Aug

18...

Sulfate, 

dissolved 

(mg/L)

17

14

13

14

11

7.9

16

14

17

32

Chloride, 

dissolved 

(mg/L)

3.2

2.5

2.9

3.1

2.1

1.5

3.6

3.1

4.1

6.5

Fluoride, 

dissolved 

(mg/L)

.2

.2

.2

.1

.1

.1

.2

.2

.2

.2

Silica, 

dissolved 

(mg/L)

21

20

19

17

17

13

22

22

25

32

Solids, 

sum of 

constituents, 

dissolved 

(mg/L)

191

176

174

171

120

103

206

199

238

318

Arsenic, 

total 

recoverable

12

10

15

15

15

14

12

19

12

14

Arsenic, 

dissolved

7

6

6

7

7

7

10

10

10

15

Cadmium, 

total 

recoverable

<l

<l

<l

<l

<1

<l

<l

<l

<1

<l

Cadmium, 

dissolved

<.l

<l

<.l

<.l

<.l

<.l

<.l

<.i

<.l

<.l

Copper, 

total 

recoverable

3

3

4

7

7

6

3

5

3

2

Copper, 

dissolved

<1

1

<1

<1

3

2

1

1

2

1

Date

Oct 1993

29...

Fcbl994

16...

Mar

09...

Apr

12...

27...

May

11...

25...

Jun

14...

Jul

12...

Aug

18...

Iron, 

total 

recoverable

420

310

550

790

930

620

250

860

220

110

Iron, 

dissolved

14

8

13

25

80

32

27

29

11

10

Lead, 

total 

recoverable

7

5

10

8

11

10

3

13

3

1

Lead, 

dissolved

<.5

<.5

<.5

<5

.5

<.5

<.5

<5

<.5

<.5

Manganese, 

total 

recoverable

(n9 )

120

100

150

160

190

180

120

250

120

80

Manganese, 

dissolved

49

15

35

32

22

26

71

39

49

56

Zinc, 

total 

recoverable

30

20

30

30

30

40

20

40

20

<10

Zinc, 

dissolved

<3

5

4

9

7

<3

<3

<3

<3

<3

Sediment, 

suspended 

(mg/L)

18

24

30

39

56

38

12

61

12

11

Sediment 

discharge, 

suspended

(ton/d)

7.3

7.8

8.5

14

44

20

2.0

34

2.6

.45

Sediment, 

suspended 

(percent 

finer than 

0.062 mm)

90

68

84

88

64

65

93

61

86

85

TABLE 4 25
Table 4. Water-quality data for the upper Clark Fork basin, Montana, October 1993 through September 1994 (Continued)

12331800--CLARK FORK NEAR DRUMMOND, MONT.

Date

Oct 1993

29...

Feb 1994

16...

Mar

09...

Apr

12...

27...

May

11...

24...

Jun

14...

Jul

12...

Aug

18...

Time

0900

1310

1200

1220

1120

1120

1945

1515

1020

1520

Stream- Specific 

flow, conductinstan- ance, 

taneous onsite 

(tP/s) (uS/cm)

774

495

566

671

1,540

1,110

942

846

424

149

441

450

442

439

304

313

381

437

501

630

PH, 

onsite 

(standard 

units)

8.1

8.3

8.3

8.4

8.2

8.2

8.4

8.4

8.2

8.5

Temperature, 

water

3.0

2.0

4.0

9.0

3.0

12.5

18.0

12.0

17.0

21.0

Hardness, 

total 

(mg/L 

as 

CaC03 )

200

210

200

200

140

140

180

200

230

300

Calcium, 

dissolved 

(mg/L)

57

59

58

58

39

40

51

56

66

83

Magnesium, 

dissolved 

(mg/L)

13

14

14

14

9.3

9.2

12

14

16

22

Sodium, 

dissolved 

(mg/L)

11

11

12

12

8.4

8.5

12

12

14

20

Potassium, 

dissolved 

(mg/L)

3.4

2.6

3.4

3.0

2.1

2.4

4.0

3.4

4.2

5.0

Alkalinity 

(mg/L 

as 

CaCO3)

153

152

148

146

103

105

136

169

186

199

Date

Oct 1993

29...

Feb 1994

16...

Mar

09...

Apr

12...

27...

May

11...

24...

Jun

14...

Jul

12...

Aug

18...

Sulfate, 

dissolved 

(mg/L)

69

81

75

75

46

46

57

57

76

130

Chloride, 

dissolved 

(mg/L)

4.4

4.7

5.2

5.3

3.4

3.3

4.1

4.4

5.3

7.8

Fluoride, 

dissolved 

(mg/L)

.4

.5

.4

.4

.3

.3

.4

.4

.4

.5

Silica, 

dissolved 

(mg/L)

19

22

19

18

18

17

20

23

24

22

Solids, 

sum of 

constituents, 

dissolved 

(mg/L)

269

286

276

273

188

190

242

272

317

410

Arsenic, 

total 

recoverable

8

9

11

14

16

17

15

12

13

11

Arsenic, 

dissolved 

(ug/L)

8

7

7

9

8

10

12

10

11

12

Cadmium, 

total 

recoverable 

(ug/L)

<i

<i

<i

<i

<i

<i

<i

<i

<i

<i

Cadmium, 

dissolved 

(ug/L)

<l

.2

<.!

<1

<.l

<1

<.l

<1

<1

<1

Copper, 

total 

recoverable 

(ug/L)

10

16

25

38

42

53

33

18

17

5

Copper, 

dissolved (ug/L)

3

4

4

5

6

1

7

5

5

4

Date

Oct 1993

29...

Feb 1994

16...

Mar

09...

Apr

12...

27...

May

11...

24...

Jun

14...

Jul

12...

Aug

18...

Iron, 

total 

recoverable

220

340

600

850

1,700

1,300

700

490

370

50

Iron, 

dissolved (ug/L)

4

6

9

10

42

18

9

10

<3

<3

Lead, 

total 

recoverable

2

4

6

18

9

4

5

2

<1

Lead, 

dissolved (ug/L)

<.5

<5

<5

<5

<5

<5

<5

<5

<5

Manganese, 

total 

recoverable

(ug/ )

50

60

90

140

240

180

100

100

110

20

Manganese, 

dissolved

13

11

15

13

12

11

11

19

14

8

Zinc, 

total 

recoverable

(ug/L)

30

30

50

60

100

80

50

40

30

<10

Zinc, 

dissolved

5

10

11

9

9

6

4

3

4

<3

Sediment, 

suspended 

(mg/L)

7

17

28

45

90

64

30

24

19

19

merit 

discharge, 

suspended

(ton/d)

15

23

43

82

374

190

76

55

22

7.6

Sediment, 

suspended 

(percent 

finer than 

0.062 mm)

90

70

71

73

55

65

75

90

81

53

26 Water-Quality, Bed-Sediment, and Biological Data (October 1993 through September 1994) and Statistical Summaries of Data for 

Streams in the Upper Clark Fork Basin, Montana.
Table 4. Water-quality data for the upper Clark Fork basin, Montana, October 1993 through September 1994 (Continued)

12334510--ROCK CREEK NEAR CLINTON, MONT.

Date

Nov 1993

01...

Fcbl994

17...

Apr

27...

May

10...

24...

Aug

18...

Time

0800

1020

1305

1715

1750

1310

Streamflow, instantaneous 

(ft*/s)

273

181

1,150

1,590

1,120

169

Specific 

conductance, 

onsite 

(uS/cm)

136

146

76

70

85

153

PH, 

onsite (standard 

units)

8.0

8.2

7.8

7.9

8.1

8.5

Temperature, 

water

3.0

1.0

5.0

12.5

13.5

16.5

Hardness, 

total 

(mg/L 

as 

CaCO3)

62

70

34

31

39

73

Calcium, 

dissolved 

(mg/L)

16

18

8.8

8.0

10

19

Magnesium, dissolved 

(mg/L)

5.4

6.2

3.0

2.6

3.3

6.3

Sodium, dissolved 

(mg/L)

2.9

3.1

2.1

1.8

2.0

3.4

Potassium, dissolved 

(mg/L)

1.2

1.1

.8

.8

1.1

1.2

Alkalinity 

(mg/L 

as 

CaCO3)

68

72

35

32

40

75

Date

Nov 1993

01...

Fcbl994

17...

Apr

27...

May

10...

24...

Aug

18...

Sulfate, 

dissolved 

(mg/L)

4.2

5.1

3.1

2.4

2.7

4.2

Chloride, 

dissolved 

(mg/L)

.6

.6

.5

.3

.4

.6

Fluoride, dissolved 

(mg/L)

.2

.1

<.l

<.l

<.l

.1

Silica, dissolved 

(mg/L)

12

13

12

10

11

10

Solids, 

sum of 

constituents, 

dissolved 

(mg/L)

83

90

51

45

55

90

Arsenic, 

total 

recoverable

<1

<l

<1

1

<1

<1

Arsenic, 

dissolved

<1

<1

<1

<1

<1

1

Cadmium, 

total 

recoverable

<l

<l

<l

<l

<l

<l

Cadmium, dissolved 

(nfl/L)

.1

<.]

<.l

<.l

<1

<.l

Copper, 

total 

recoverable

<l

<l

<l

l

l

<1

Copper, 

dissolved

<l

<l

<1

<l

<l

<l

Date

Nov 1993

01...

Fcbl994

17...

Apr

27...

May

10...

24...

Aug

18...

Iron, 

total 

recoverable

80

40

220

370

140

50

Iron, dissolved

12

5

62

36

29

9

Lead, 

total 

recoverable

<l

<1

<l

<l

<l

<l

Lead, dissolved

<.5

<.5

<.5

<.5

<.5

<.5

Manganese, 

total 

recoverable

(ng/ )

<10

<10

10

20

<10

<10

Manganese, 

dissolved

<1

<1

1

2

2

1

Zinc, 

total 

recoverable

<10

<10

<10

<10

<10

<10

Zinc, dissolved

<3

3

<3

<3

<3

<3

Sediment, 

suspended 

(mg/L)

2

2

8

24

6

2

OA«J: Sediment 

discharge, 

suspended

(ton/d)

1.5

.98

25

103

18

.91

Sediment, 

suspended 

(percent 

finer than 

0.062 mm)

69

74

80

65

71

89

TABLE 4 27
Table 4. Water-quality data for the upper Clark Fork basin, Montana, October 1993 through September 1994 (Continued) 

12334550-CLARK FORK AT TURAH BRIDGE, NEAR BONNER, MONT.

Date

Nov 1993

01...

Fcbl994

17...

Mar

10...

Apr

12...

27...

May

10...

24...

Jun

14...

Jul

12...

Aug

18...

Stream- Specific 

flow, conductTime instan- ance, 

taneous onsite 

(ft3/s) (uS/cm)

0945

1145

1030

1440

1515

1450

1520

1015

1245

1120

1,110

728

802

988

2,850

2,580

2,200

1,760

904

328

369

371

379

371

221

200

244

275

327

356

pH 

onsite (standard 

units)

8.4

8.4

8.3

8.5

8.1

8.2

8.4

8.3

8.5

8.4

Temperature, 

water

3.0

1.5

3.0

10.0

6.0

14.0

15.5

10.5

17.5

16.0

Hardness, 

total 

(mg/L 

as 

CaCO3)

160

170

170

170

96

89

110

120

150

160

Calcium, 

dissolved 

(mg/L)

46

49

48

47

27

25

31

34

42

44

Magnesium, 

dissolved 

(mg/L)

11

12

12

12

7.0

6.4

7.9

8.8

11

13

Sodium, 

dissolved 

(mg/L)

9.2

9.5

9.6

9.9

5.8

5.3

6.6

7.2

8.4

9.3

Potassium, 

dissolved 

(mg/L)

2.5

2.4

2.6

2.5

1.7

1.6

2.5

2.0

2.7

2.6

Alkalinity 

(mg/L 

as 

CaC03)

133

133

131

128

80

73

90

107

128

127

Date

Nov 1993

01...

Fcbl994

17...

Mar

10...

Apr

12...

27...

May

10...

24...

Jun

14...

Jul

12...

Aug

18...

Sulfate, 

dissolved 

(mg/L)

55

60

58

59

28

25

30

30

41

53

Chloride, 

dissolved 

(mg/L)

3.3

3.5

3.9

4.2

2.2

1.8

2.2

2.3

2.9

3.1

Fluoride, 

dissolved 

(mg/L)

.4

.4

.4

.4

.2

.2

.2

.2

.3

.3

Silica, 

dissolved 

(mg/L)

17

19

17

16

15

13

15

16

15

12

Solids, 

sum of 

constituents, 

dissolved 

(mg/L)

224

236

230

228

135

122

149

165

200

213

Arsenic, 

total 

recoverable

6

7

9

9

9

5

8

6

6

5

Arsenic, 

dissolved

(Mg/L)

5

5

5

7

5

5

6

5

6

5

Cadmium, 

total 

recoverable

<l

<1

<1

<1

<l

<1

<1

<1

<1

<1

Cadmium, 

dissolved 

(M9/L)

<.l

<1

<1

<1

<1

<.l

<1

<.l

<1

<.l

Copper, 

total 

recoverable 

(H9/L)

7

13

19

23

42

27

18

12

8

3

Copper, 

dissolved 

(WJ/L)

3

3

3

4

5

4

5

3

3

2

Date

Nov 1993

01...

Fcbl994

17...

Mar

10...

Apr

12...

27...

May

10...

24...

Jun

14...

Jul

12...

Aug

18...

Iron, 

total 

recoverable 

(Mg/L)

140

280

450

530

1,100

800

500

390

150

60

Iron, 

dissolved

(Mg/L)

<3

5

8

7

41

22

16

16

6

6

Lead, 

total 

recoverable

2

3

4

10

5

3

2

1

<1

Lead, dissolved

<5

<5

<5

.6

<5

<5

<.5

<5

<5

Manganese, 

total 

recoverable

g/ '

20

50

70

90

160

100

70

50

30

20

Manganese, 

dissolved

4

6

9

7

10

7

6

4

5

5

Zinc, 

total 

recoverable 

(Mg/L)

20

30

30

40

70

50

30

30

30

<10

Zinc, 

dissolved 

(Mg/L)

5

8

11

9

12

<3

5

<3

<3

3

Sediment, 

suspended 

(mg/L)

4

14

21

26

58

60

26

24

8

4

merit 

discharge, 

suspended

(ton/d)

12

28

45

69

446

418

154

114

20

3.5

Sediment, 

suspended 

(percent 

finer than 

0.062 mm)

91

80

83

80

57

52

57

62

88

85

28 Water-Quality, Bed-Sediment, and Biological Data (October 1993 through September 1994) and Statistical Summaries of Data for 

Streams in the Upper Clark Fork Basin, Montana.
Table 4. Water-quality data for the upper Clark Fork basin, Montana, October 1993 through September 1994 (Continued)

12340000--BLACKFOOT RIVER NEAR BONNER, MONT.

Date

Nov 1993

01...

Febl994

17...

Apr

28...

May

10...

24...

Aug

18...

Time

1140

1330

0830

1305

1040

0930

Stream- Specific 

flow, conductinstan- ance, 

taneous onsrte 

(fl3/s) (uS/cm)

729

E500

4,250

4,570

3,160

419

263

261

168

159

189

262

PH, 

onsite (standard 

units)

8.6

8.5

8.3

8.2

8.3

8.4

Temperature, 

water

4.0

0.0

4.5

12.0

13.0

15.5

Hardness, 

total 

(mg/L 

as 

CaC03)

140

130

85

81

94

130

Calcium, dissolved 

(mg/L)

35

34

22

21

24

32

Magnesium, 

dissolved 

(mg/L)

12

12

7.4

7.0

8.3

13

Sodium, dissolved 

(mg/L)

3.4

3.2

1.8

1.4

2.1

3.1

Potas- Alkasium, Unity 

dis- (mg/L 

solved as 

(mg/L) CaCO3)

1.0 140

.9 139

.6 86

.5 83

.8 95

1.0 135

Date

Nov 1993

01...

Febl994

17...

Apr

28...

May

10...

24...

Aug

18...

Sulfate, dissolved 

(mg/L)

6.6

6.1

4.2

1.1

4.6

5.2

Chloride, dissolved 

(mg/L)

.6

.7

.4

.3

.4

.6

Fluoride, 

dissolved 

(mg/L)

.1

<.l

<.l

<.l

<.l

<.l

Silica, dissolved 

(mg/L)

11

12

8.6

7.0

8.1

9.5

Solids, 

sum of 

constituents, 

dissolved 

(mg/L)

154

152

97

88

105

145

Arsenic, 

total 

recoverable 

(ug/L)

<1

1

<1

1

1

<1

Arsenic, dissolved 

(ug/L)

1

1

<i

<1

<1

1

Cadmium, 

total 

recoverable 

(ug/L)

<l

<l

<i

<l

<1

<1

Cadmium, dissolved 

(ug/L)

<.!

<.l

<.l

<.l

<.l

<.l

Copper, Conner 

total dlS 

recov- sohjLj 

erable **? (ug/L) ("9/1-)

..

1 <1

3 1

4 <1

2 <1

<1 <1

Date

Nov 1993

01...

Febl994

17...

Apr

28...

May

10...

24...

Aug

18...

Iron, 

total 

recoverable

(ug/L)

80

50

410

550

180

20

Iron, dissolved (ug/L)

4

5

22

14

10

<3

Lead, 

total 

recoverable

(ug/L)

<i

i

2

<1

<1

Lead, dissolved 

(ug/L)

<.5

<.5

<.5

<.5

<.5

Manganese, 

total 

recoverable (ug/L)

<10

<10

30

40

10

<10

Manganese, dissolved

(ug/L)

i

<i

3

3

2

1

Zinc, 

total 

recoverable (ug/L)

20

<10

<10

<10

<10

<10

Zinc, dissolved 

(ug/L)

<3

<3

<3

<3

<3

<3

Sediment, 

suspended 

(mg/L)

2

2

24

45

10

2

Sediment Sediment, 

dis- suspended 

charge, (percent 

sus- finer than 

pended 0.062 mm) 

(ton/d)

3.9 79

2.7 80

275 82

555 81

85 87

2.3 81

TABLE 4 29
Table 4. Water-quality data for the upper Clark Fork basin, Montana, October 1993 through September 1994 (Continued)

12340500-CLARK FORK ABOVE MISSOULA, MONT.

Date

Nov 1993

01...

Feb 1994

17...

Mar

10...

Apr

13...

28...

May

10...

24...

Jun

14...

Jul

12...

Aug

18...

Stream- Specific 

flow, conductTime instan- ance, 

taneous onsite 

(fp/s) (uS/cm)

1315

1620

1220

0830

1020

1100

1330

0750

1450

0725

1,800

1,260

1,330

2,190

6,150

6,790

5,220

3,680

1,710

817

332

330

325

281

189

177

213

239

287

299

PH, 

onsite 

(standard 

units)

8.4

8.4

8.5

8.3

8.2

8.1

8.2

8.3

8.3

8.5

Temperature, 

water

4.0

0.0

3.5

7.0

5.5

12.0

13.0

12.0

18.0

17.5

Hardness, 

total 

(mg/L 

as 

CaC03)

160

160

150

130

90

86

100

110

140

150

Calcium, I?""*- 

dis- aiu(msolved .°^ /m_/i \ solved ^fl"-) (mg/L)

43 12

43 12

42 12

35 10

24 7.2

23 7.0

27 8.1

31 9.1

36 11

37 13

Sodium, P<***- 

dis- aiu'"'

f±S a°** f"*71-* (mg/L)

7.2 2.3

7.2 1.8

7.3 2.3

6.0 1.6

3.3 1.0

2.9 .9

4.0 1.5

4.4 1.2

5.7 1.8

6.0 1.7

Alkalinity 

(mg/L 

as 

CaCO3)

136

134

131

115

84

80

94

107

128

128

Date

Nov 1993

01...

Feb 1994

17...

Mar

10...

Apr

13...

28...

May

10...

24...

Jun

14...

Jul

12...

Aug

18...

Sulfate, 

dissolved 

(mg/L)

35

39

37

28

13

11

15

16

23

25

Chloride, 

dissolved 

(mg/L)

2.2

2.4

2.8

2.2

1.1

.9

1.2

1.3

1.8

1.8

Fluoride, 

dissolved 

(mg/L)

.3

.3

.3

.2

.1

<.!

.1

.1

.2

.2

Siiica, 

dissolved 

(mg/L)

15

16

14

12

11

9.4

11

11

12

11

Solids, 

sum of 

constituents, 

dissolved 

(mg/L)

199

202

196

164

111

103

124

138

168

172

Arsenic, 

total 

recoverable

4

5

6

4

3

3

4

3

4

3

CadArsenic, mium, 

dis- total 

solved recov- 

(ug/L) erable

4 <1

4 <1

4 <1

3 <1

2 <1

2 <1

3 <1

3 <1

3 <1

3 <1

Cad- Copper, 

mlum, total 

dis- recovsolved erable

<1 4

<.l 6

<1 8

<1 10

<1 11

<1 14

<.l 8

<1 7

<.l 7

<1 5

Copper, 

dissolved

2

2

2

2

2

2

2

2

2

2

Date

Nov 1993

01...

Feb 1994

17...

Mar

10...

Apr

13...

28...

May

10...

24...

Jun

14...

Jul

12...

Aug

18...

Iron, 

total 

recoverable

110

110

220

270

520

560

310

220

150

120

Iron, 

dissolved

3

5

11

19

40

21

16

14

10

8

Lead, 

total 

recoverable

1

<1

1

2

2

3

1

1

<1

1

Lead, 

dissolved

<5

<5

<.5

<.5

<5

<5

<.5

<.5

<.5

<5

Manganese, 

total 

recoverable

10

30

50

50

60

60

40

30

30

30

Manganese, 

dissolved (nfl'L)

7

13

29

25

11

18

15

13

19

13

Zinc, ~__ 

total 5*

eraWe *>*"« eraoie (ug/L)

20 <3

20 12

10 9

20 8

20 7

20 <3

20 <3

10 <3

40 <3

<10 <3

Sarii. OOlllSedi- ment 

merit, dissus- charge, 

pended sus- 

(mg/L) P«nd«d

(ton/d)

3 15

4 14

7 25

10 59

28 465

34 623

14 197

12 119

6 28

6 13

Sediment, 

suspended 

(percent 

finer than 

0.062 mm)

90

90

96

97

93

89

92

93

98

88

30 Water-Quality, Bed-Sediment, and Biological Data (October 1993 through September 1994) and Statistical Summaries of Data for 

Streams in the Upper Clark Fork Basin, Montana.
Table 4. Water-quality data for the upper Clark Fork basin, Montana, October 1993 through September 1994 (Continued)

12353000--CLARK FORK BELOW MISSOULA, MONT.

Date

Dec 1993

01...

Mar 1994

03...

30...

May

11...

Jun

08...

Sep

13...

Time

1230

1000

1030

1030

1000

1100

Stream- Specific 

flow, conductinstan- ance, 

taneous onsfte 

(fP/s) (uS/cm)

2,400 276

2,780 263

2,090 252

13,800 109

7,950 150

1,190 274

PH, 

onsite 

(standard 

units)

8.2

8.2

8.3

8.1

8.2

8.2

Temperature, 

water

1.0

4.0

7.5

11.0

11.5

13.0

Hardness, 

total 

(mg/L 

as 

CaCO3)

130

110

120

48

69

120

*«- "ST

dis 

Sjjrt solved (m9/L) (mg/L)

35 9.2

32 8.5

33 8.7

13 3.7

19 5.1

34 9.6

Sodium, 

dissolved 

(mg/L)

7.1

6.6

6.4

2.2

3.5

6.9

Potas- Alkasium, linlty 

dis- (mgA. 

solved as 

(mg/L) CaCO3)

1.7 116

3.4 103

1.6 105

.7 49

1.1 68

1.9 121

Date

Dec 1993

01...

Mar 1994

03...

30...

May

11...

Jun

08...

Sep

13...

Sulfate, 

dissolved 

(mg/L)

28

25

22

6.3

8.7

18

Chloride. "US" 

dis- "?«'

?±S *« 

<m»/L) (mg/L)

2.6 .2

3.6 .2

2.4 .2

.7 <.l

1.2 .1

2.7 .2

Silica, 

dissolved 

(mg/L)

14

13

11

8.5

9.6

10

Solids, 

sum of 

constituents, 

dissolved 

(mg/L)

177

150

143

63

90

157

Arsenic, 

total 

recoverable (ng/L)

3

..

3

2

2

CadArsenic, mium, 

dis- total 

solved recov- 

(ug/L) erable (ng/L)

3 <1

2 <1

..

1 <1

3 <1

Cadmium, 

dissolved (ng/L)

<1

-

<1

-

.1

<1

Copper, Conner 

total dff S» «s

5 2

5 2

..

8 3

2 2

Date

Dec 1993

01...

Mar 1994

03...

30...

May

11...

Jun

08...

Sep

13...

Iron, 

total 

recoverable

140

150

-

1,980

90

,,. Lead, 

dis-' totel

rss ^S71-) SE(ng/L)

17

21 <1

29 2

16 <1

Lead, dissolved (ng/L)

<5

-

<5

<.5

Manganese, 

total 

recoverable

(ng/L)

20

30

-

20

20

Manganese, 

dissolved (ng/L)

9

-

13

-

5

5

Zinc, 7lnr, t«tai Zinc, toiai jj

recov- S0|ved

ass ^

30 <10

_

10 <10

..

10 <10

<10 <10

Sediment, 

suspended 

(mg/L)

5

37

6

40

8

4

C^^Ji sediment Sediment, 

dis- suspended 

charge, (percent 

sus- finer than 

pended 0.062 mm) 

(ton/d)

32 85

278 89

34 89

1,490 70

172 79

13 84

TABLE 4 31
Table 5. Daily streamflow and suspended-sediment data for Silver Bow Creek at Opportunity, Montana, October 1993 through 

September 1994

[Abbreviations: ftVs, cubic feet per second; mg/L, milligrams per liter; ton/d, tons per day. Symbol: , no data]

Suspended sediment

Day

1

2

3

4

5

6

7

8

9

10

11

12

13

14

15

16

17

18

19

20

21

22

23

24

25

26

27

28

29

30

31

TOTAL

MEAN

MAX

MIN

Mean 

streamflow 

(ft3/s)

48

48

48

48

47

48

54

57

58

55

55

56

56

56

56

58

55

53

51

53

52

50

51

51

49

48

44

49

45

44

46

1,589

51.3

58

44

Mean 

concentration 

(mg/L)

October

8

8

8

7

8

10

13

14

12

11

10

9

8

8

9

9

9

8

7

9

8

7

7

7

6

6

5

8

6

6

6

. 

8

14

5

Discharge 

(ton/d)

1.0

1.0

1.0

.91

1.0

1.3

1.9

2.2

1.9

1.6

1.5

1.4

1.2

1.2

1.4

1.4

1.3

1.1

.96

1.3

1.1

.95

.96

.96

.79

.78

.59

1.1

.73

.71

.75

35.99

1.2

2.2

.59

Mean 

streamflow 

(«3/s)

1993

48

45

47

46

39

37

48

48

46

54

50

46

46

47

48

48

45

44

43

45

45

40

30

20

15

16

18

20

22

24

1,170

39.0

54

15

Suspended sediment

Mean 

concentration 

(mg/L)

November

6

7

7

7

8

9

10

11

12

13

14

15

14

13

11

10

11

14

16

17

15

12

10

7

6

9

12

16

16

14

_

11

17

6

Discharge 

(ton/d)

.78

.85

.89

.87

.84

.90

1.3

1.4

1.5

1.9

1.9

1.9

1.7

1.6

1.4

1.3

1.3

1.7

1.9

2.1

1.8

1.3

.81

.38

.24

.39

.58

.86

.95

.91

36.25

1.2

2.1

.24

Mean 

streamfiow 

(ft3/s)

24

25

25

24

24

22

20

20

21

22

23

24

25

26

27

26

26

25

24

24

24

23

22

22

22

23

23

23

25

27

30

741

23.9

30

20

Suspended sediment

Mean 

concentration 

(mg/L)

December

17

21

26

31

39

59

66

70

80

120

90

45

37

36

36

36

36

42

44

40

39

38

33

25

18

16

16

17

18

18

20

40

120

16

Discharge 

(ton/d)

l.l

1.4

1.8

2.0

2.5

3.5

3.6

3.8

4.5

7.1

5.6

2.9

2.5

2.5

2.6

2.5

2.5

2.8

2.9

2.6

2.5

2.4

2.0

1.5

1.1

.99

.99

1.1

1.2

1.3

1.6

77.38

2.5

7.1

.99

32 Water-Quality, Bed-Sediment, and Biological Data (October 1993 through September 1994) and Statistical Summaries of Data for 

Streams in the Upper Clark Fork Basin, Montana.
Table 5. Daily streamflow and suspended-sediment data for Silver Bow Creek at Opportunity, Montana, October 1993 through 

September 1994 (Continued)

Suspended sediment

Day

1

2

3

4

5

6

7

8

9

10

11

12

13

14

15

16

17

18

19

20

21

22

23

24

25

26

27

28

29

30

31

TOTAL

MEAN

MAX

M1N

Mean 

streamflow 

(ft3/s)

33

35

37

38

40

37

35

30

27

28

30

30

29

29

35

32

32

33

34

33

30

32

32

32

32

32

32

31

27

26

25

988

31.9

40

25

Mean 

concentration 

(mg/L)

January

22

24

24

21

17

14

14

16

19

22

26

29

32

35

35

30

24

19

16

14

14

14

15

14

12

11

10

10

10

10

26

...

19

35

10

Discharge 

(ton/d)

2.0

2.3

2.4

2.2

1.8

1.4

1.3

1.3

1.4

1.7

2.1

2.3

2.5

2.7

3.3

2.6

2.1

1.7

1.5

1.2

1.1

1.2

1.3

1.2

1.0

.95

.86

.84

.73

.70

1.8

51.48

1.7

3.3

.70

Mean 

streamflow 

(ft3/s)

1994

25

25

25

24

23

23

23

24

27

30

32

34

35

38

40

45

50

47

44

42

40

40

40

38

36

36

40

45

...

...

971

34.7

50

23

Suspended sediment

Mean 

concentration 

(mg/L)

February

20

4

3

3

3

3

3

4

4

5

6

7

7

8

8

9

8

6

8

10

11

11

11

11

11

11

11

11

...

...

...

_

8

20

3

Discharge 

(ton/d)

1.4

.27

.20

19

.19

.19

.19

.26

.29

.41

.52

.64

.66

.82

.86

1.1

1.1

.76

.95

1.1

1.2

1.2

1.2

1.1

1.1

1.1

1.2

1.3

...

...

...

21.50

.77

1.4

.19

Mean 

streamflow 

(ft3/s)

50

58

70

59

52

46

44

43

41

40

39

42

44

47

50

58

55

51

49

43

47

44

43

40

42

43

43

44

42

43

46

1,458

47.0

70

39

Suspended sediment

Mean 

concentration 

(mg/L)

March

160

185

100

34

22

16

15

14

15

10

7

6

9

13

15

30

18

12

8

9

10

8

12

21

8

10

7

5

6

6

10

...

26

185

5

Discharge 

(ton/d)

22

29

19

5.4

3.1

2.0

1.8

1.6

1.7

1.1

.74

.68

1.1

1.6

2.0

4.7

2.7

1.7

1.1

1.0

1.3

.95

1.4

2.3

.91

1.2

.81

.59

.68

.70

1.2

116.06

3.7

29

.59

TABLE 5 33
Table 5. Daily streamflow and suspended-sediment data for Silver Bow Creek at Opportunity, Montana, October 1993 through 

September 1994 (Continued)

Suspended sediment

Day

1

2

3

4

5

6

7

8

9

10

11

12

13

14

15

16

17

18

19

20

21

22

23

24

25

26

27

28

29

30

31

MEAN

MAX

MIN

TOTAL

Mean 

streamflow 

(tf/s)

51

57

60

62

56

56

54

54

54

57

60

62

64

63

59

63

80

100

109

117

120

133

143

135

139

128

116

103

96

97

...

84.9

143

51

2,548

Mean 

concentration 

(mg/L)

April

18

24

27

27

14

14

12

13

13

16

19

23

26

18

14

18

61

86

78

74

62

71

66

50

38

32

28

22

23

20

34

86

12

Discharge 

(ton/d)

2.5

3.7

4.4

4.5

2.1

2.1

1.7

1.9

1.9

2.5

3.1

3.9

4.5

3.1

2.2

3.1

13

23

23

23

20

25

25

18

14

11

8.8

6.1

6.0

5.2

8.9

25

1.7

268.3

Mean 

streamflow 

(ft3/s)

1994

100

95

91

88

87

89

92

95

100

106

103

105

112

103

98

98

105

114

135

139

116

109

110

100

92

89

88

107

93

84

74

101

139

74

3,117

Suspended sediment

Mean 

concentration 

(mg/L)

May

18

13

12

12

10

13

11

13

17

18

14

17

15

15

11

13

18

20

57

49

25

19

20

17

15

17

17

24

16

13

12

18

57

10

...

Discharge 

(ton/d)

4.9

3.3

2.9

2.9

2.3

3.1

2.7

3.3

4.6

5.2

3.9

4.8

4.5

4.2

2.9

3.4

5.1

6.2

21

18

7.8

5.6

5.9

4.6

3.7

4.1

4.0

6.9

4.0

2.9

2.4

5.2

21

2.3

161.1

Mean 

streamflow 

(ft3/s)

76

75

68

68

61

57

64

67

64

59

52

55

54

68

61

69

64

58

51

43

42

43

40

45

44

43

42

42

39

38

55.1

76

38

1,652

Suspended sediment

Mean 

concentration 

(mg/L)

June

14

13

12

12

13

13

16

13

11

9

7

11

11

19

10

13

13

10

8

8

7

7

7

7

8

8

8

7

6

8

10

19

6

...

Discharge 

(ton/d)

2.9

2.6

2.2

2.2

2.1

2.0

2.8

2.4

1.9

1.4

.98

1.6

1.6

3.5

1.6

2.4

2.2

1.6

1.1

.93

.79

.81

.76

.85

.95

.93

.91

.79

.63

.82

1.6

3.5

.63

48.25

34 Water-Quality, Bed-Sediment, and Biological Data (October 1993 through September 1994) and Statistical Summaries of Data for 

Streams in the Upper Clark Fork Basin, Montana.
Table 5. Daily streamflow and suspended-sediment data for Silver Bow Creek at Opportunity, Montana, October 1993 through 

September 1994 (Continued)

Suspended sediment

Day

1

2

3

4

5

6

7

8

9

10

11

12

13

14

15

16

17

18

19

20

21

22

23

24

25

26

27

28

29

30

31

TOTAL

MEAN

MAX

MIN

Mean 

streamflow 

(ft3/s)

41

38

37

37

41

159

93

73

63

62

55

52

48

41

41

40

38

36

33

30

26

29

29

33

32

30

33

36

30

29

34

1,399

45.1

159

26

Mean 

concentration 

(mg/L)

July

9

7

6

5

40

239

43

18

13

14

11

8

6

6

6

5

5

4

4

4

4

3

4

6

7

7

8

7

5

5

7

_

17

239

3

Discharge 

(ton/d)

1.0

.72

.60

.50

4.4

103

11

3.5

2.2

2.3

1.6

1.1

.78

.66

.66

.54

.51

.39

.36

.32

.28

.23

.31

.53

.60

.57

.71

.68

.41

.39

.64

141.49

4.6

103

.23

Mean 

streamflow 

(ft3/s)

28

28

28

27

26

25

24

25

25

24

22

27

26

23

23

24

25

22

23

23

23

23

27

23

24

23

22

23

24

28

25

763

24.6

28

22

Suspended sediment

Mean 

concentration 

(mg/L)

1994

August

6

6

7

8

10

11

11

11

11

10

9

7

5

4

4

5

7

10

8

6

6

6

9

6

6

6

6

6

6

6

7

7

11

4

Discharge 

(ton/d)

.45

.45

.53

.58

.70

.74

.71

.74

.74

.65

.53

.51

.35

.25

.25

.32

.47

.59

.50

.37

.37

.37

.66

.37

.39

.37

.36

.37

.39

.45

.47

15.00

.48

.74

.25

Mean 

streamflow 

(ft3/s)

27

24

22

22

23

23

22

20

24

22

22

24

24

25

24

24

22

22

24

26

25

27

28

25

27

28

28

27

27

30

738

24.6

30

20

Suspended sediment

Mean 

concentration 

(mg/L)

September

11

14

16

13

10

7

5

5

7

9

9

7

6

5

5

7

11

13

15

15

11

8

8

8

10

12

12

12

13

13

...

10

16

5

Discharge 

(ton/d)

.80

.91

.95

.77

.62

.43

.30

.27

.45

.53

.53

.45

.39

.34

.32

.45

.65

.77

.97

1.1

.74

.58

.60

.54

.73

.91

.91

.87

.95

1.1

...

19.93

.66

1.1

.27

TOTAL FOR WATER YEAR 1994: 

STREAMFLOW--17.134 ft7/s 

SEDIMENT DBCHARQE--992.73 tons

TABLE 5 35
Table 6. Daily streamflow and suspended-sediment data for Silver Bow Creek at Warm Springs, Montana, October 1993 

through September 1994

[Abbreviations: fr/s, cubic feet per second; mg/L, milligrams per liter; ton/d, tons per day. Symbol: , no data]

Suspended sediment

Day

1

2

3

4

5

6

7

8

9

10

11

12

13

14

15

16

17

18

19

20

21

22

23

24

25

26

27

28

29

30

31

TOTAL

MEAN

MAX

MIN

Mean 

streamflow

(ft3/s)

80

74

70

69

69

66

63

65

70

72

53

49

57

62

58

69

75

79

79

78

78

78

78

75

74

74

74

74

77

76

76

2,191

70.7

80

49

Mean 

concentration 

(mg/L)

October

2

2

1

1

1

1

2

2

1

1

3

4

5

5

5

5

4

5

8

8

7

6

7

7

7

8

8

20

6

4

5

_.

5

20

1

Discharge 

(ton/d)

.43

.40

.19

.19

.19

.18

.34

.35

.19

.19

.43

.53

.77

.84

.78

.93

.81

1.1

1.7

1.7

1.5

1.3

1.5

1.4

1.4

1.6

1.6

4.0

1.2

.82

1.0

29.56

.95

4.0

.18

Mean 

streamflow 

(ft3/s)

1993

68

78

83

80

80

79

78

78

80

81

81

82

82

81

82

79

80

81

80

79

78

76

78

70

64

60

58

57

58

61

2,252

75.1

83

57

Suspended sediment

Mean 

concentration 

(mg/L)

November

6

6

7

7

6

6

5

4

4

3

3

3

2

3

3

7

4

3

3

4

3

4

16

11

7

5

6

4

6

5

_

5

16

2

Discharge 

(ton/d)

1.1

1.3

1.6

1.5

1.3

1.3

1.1

.84

.86

.66

.66

.66

.44

.66

.66

1.5

.86

.66

.65

.85

.63

.82

3.4

2.1

1.2

.81

.94

.62

.94

.82

31.44

1.1

3.4

.44

Mean 

streamflow 

(ft3/s)

67

70

72

70

70

70

69

66

66

68

70

72

73

72

70

69

68

66

65

64

63

67

74

79

76

73

72

77

82

80

75

2,195

70.8

82

63

Suspended sediment

Mean 

concentration 

(mg/L)

December

4

5

8

3

8

7

6

5

4

4

4

4

5

5

4

4

5

5

6

6

6

5

6

6

6

5

7

8

7

6

7

6

8

3

Discharge 

(ton/d)

.72

.95

1.6

.57

1.5

1.3

1.1

.89

.71

.73

.76

.78

.99

.97

.76

.75

.92

.89

1.1

1.0

1.0

.90

1.2

1.3

1.2

.99

.4

.7

.5

.3

.4

32.88

1.1

1.7

.57

36 Water-Quality, Bed-Sediment, and Bioiogical Data (October 1993 through September 1994) and Statistical Summaries of Data for 

Streams in the Upper Clark Fork Basin, Montana.
Table 6. Daily streamflow and suspended-sediment data for Silver Bow Creek at Warm Springs, Montana, October 1993 

through September 1994 (Continued)

Suspended sediment

Day

1

2

3

4

5

6

7

8

9

10

11

12

13

14

15

16

17

18

19

20

21

22

23

24

25

26

27

28

29

30

31

TOTAL

MEAN

MAX

M3N

Mean 

streamflow 

(ft3/s)

71

70

69

70

69

69

68

64

64

65

65

65

65

67

69

69

68

68

66

66

67

66

65

64

65

66

66

66

65

66

63

2,066

66.6

71

63

Mean 

concentration 

(mg/L)

January

5

5

6

7

6

6

6

6

6

6

8

13

7

6

6

6

7

7

7

7

10

8

7

7

7

8

8

8

8

8

7

...

7

13

5

Discharge 

(ton/d)

.96

.95

1.1

1.3

1.1

1.1

1.1

1.0

1.0

1.1

1.4

2.3

1.2

1.1

1.1

1.1

1.3

1.3

1.2

1.2

1.8

1.4

1.2

1.2

1.2

1.4

1.4

1.4

1.4

1.4

1.2

38.91

1.3

2.3

.95

Mean 

streamflow 

(ft3/s)

1994

61

60

59

58

58

57

57

57

56

52

51

51

51

49

51

51

52

55

57

57

58

59

61

59

61

61

62

64

...

...

...

1,585

56.6

64

49

Suspended sediment

Mean 

concentration 

(mg/L)

February

6

6

6

6

6

6

8

6

7

8

7

7

6

5

6

6

5

6

8

6

5

7

8

7

7

7

6

6

...

...

-

6

8

5

Discharge 

(ton/d)

.99

.97

.96

.94

.94

.92

1.2

.92

1.1

1.1

.96

.96

.83

.66

.83

.83

.70

.89

1.2

.92

.78

1.1

1.3

1.1

1.2

1.2

1.0

1.0

...

...

...

27.50

.98

1.3

.66

Mean 

streamflow 

(ft3/s)

65

73

88

97

99

96

89

84

79

76

73

71

71

68

69

71

67

70

67

70

68

69

71

72

71

70

70

72

73

72

72

2323

74.9

99

65

Suspended sediment

Mean 

concentration 

(mg/L)

March

7

8

11

14

14

8

8

7

7

7

7

6

5

5

6

7

11

8

7

6

8

7

8

6

7

6

7

7

7

7

8

...

8

14

5

Discharge 

(ton/d)

1.2

1.6

2.6

3.7

3.7

2.1

1.9

1.6

1.5

1.4

1.4

1.2

.96

.92

1.1

1.3

2.0

1.5

1.3

1.1

1.5

1.3

1.5

1.2

1.3

1.1

1.3

1.4

1.4

1.4

1.6

49.08

1.6

3.7

.92

TABLE 6 37
Table 6. Daily streamflow and suspended-sediment data for Silver Bow Creek at Warm Springs, Montana, October 1993 

through September 1994 (Continued)

Suspended sediment

Day

1

2

3

4

5

6

7

8

9

10

11

12

13

14

15

16

17

18

19

20

21

22

23

24

25

26

27

28

29

30

31

TOTAL

MEAN

MAX

M1N

Mean 

streamflow 

(ft3/s)

71

73

80

92

95

96

106

105

98

95

94

97

94

94

94

94

94

99

114

134

145

159

179

184

184

186

186

186

188

187

3,703

123

188

71

Mean 

concentration 

(mg/L)

April

8

7

8

9

8

9

10

9

7

8

7

8

9

8

6

6

6

7

10

14

16

30

34

26

20

17

15

14

11

11

_

12

34

6

Discharge 

(ton/d)

1.5

1.4

1.7

2.2

2.1

2.3

2.9

2.6

1.9

2.1

1.8

2.1

2.3

2.0

1.5

1.5

1.5

1.9

3.1

5.1

6.3

13

16

13

9.9

8.5

7.5

7.0

5.6

5.6

135.9

4.5

16

1.4

Mean 

streamflow 

(ft3/s)

1994

186

187

185

185

189

182

172

166

165

168

173

186

185

182

183

182

182

182

182

182

182

182

182

182

180

190

199

198

191

185

183

5,658

183

199

165

Suspended sediment

Mean 

concentration 

(mg/L)

May

11

10

10

9

11

13

13

12

11

10

10

12

11

14

10

20

42

66

50

20

12

9

10

9

6

9

8

5

5

3

3

14

66

3

Discharge 

(ton/d)

5.5

5.0

5.0

4.5

5.6

6.4

6.0

5.4

4.9

4.5

4.7

6.0

5.5

6.9

4.9

9.8

21

32

25

9.8

5.9

4.4

4.9

4.4

2.9

4.6

4.3

2.7

2.6

1.5

1.5

218.1

7.0

32

1.5

Mean 

streamflow 

(ft3/s)

185

180

168

148

128

119

112

97

82

69

71

76

83

90

92

95

96

94

88

83

79

77

75

69

67

65

61

58

56

56

2,819

94.0

185

56

Suspended sediment

Mean 

concentration 

(mg/L)

June

4

4

4

4

4

4

4

4

4

4

4

4

4

4

5

8

9

5

3

4

3

3

2

2

2

4

4

4

4

4

...

4

9

2

Discharge 

(ton/d)

2.0

1.9

1.8

1.6

1.4

1.3

1.2

1.0

.89

.75

.77

.82

.90

.97

1.2

2.1

2.3

1.3

.71

.90

.64

.62

.41

.37

.36

.70

.66

.63

.60

.60

31.40

1.1

2.3

.36

38 Water-Quality, Bed-Sediment, and Biological Data (October 1993 through September 1994) and Statistical Summaries of Data for 

Streams in the Upper Clark Fork Basin, Montana.
Table 6. Daily streamflow and suspended-sediment data for Silver Bow Creek at Warm Springs, Montana, October 1993 

through September 1994 (Continued)

Suspended sediment

Day

1

2

3

4

5

6

7

8

9

10

11

12

13

14

15

16

17

18

19

20

21

22

23

24

25

26

27

28

29

30

31

TOTAL

MEAN

MAX

MIN

Mean 

streamflow 

(tf/s)

58

55

53

53

55

73

97

112

106

96

89

84

81

79

74

67

65

61

57

54

53

47

46

45

46

46

44

46

46

45

43

1,976

63.7

112

43

Mean 

concentration 

(mg/L)

July

4

4

4

4

4

7

8

6

4

4

4

4

3

3

3

3

2

2

2

2

2

2

4

4

4

4

5

4

5

5

4

_

4

8

2

Discharge 

(ton/d)

.63

.59

.57

.57

.59

1.4

2.1

1.8

1.1

1.0

.96

.91

.66

.64

.60

.54

.35

.33

.31

.29

.29

.25

.50

.49

.50

.50

.59

.50

.62

.61

.46

21.25

.69

2.1

.25

Mean 

streamflow 

(ft3/s)

41

40

37

36

32

30

29

28

28

28

27

26

26

26

26

25

24

23

23

24

24

23

23

22

22

21

22

21

21

22

22

822

26.5

41

21

Suspended sediment

Mean 

concentration 

(mg/L)

1994

August

4

4

4

5

4

4

4

4

3

3

3

3

2

2

2

2

3

2

2

4

4

2

2

3

4

5

4

3

3

2

2

3

5

2

Discharge 

(ton/d)

.44

.43

.40

.49

.35

.32

.31

.30

.23

.23

.22

.21

.14

.14

.14

.14

.19

.12

.12

.26

.26

.12

.12

.18

.24

.28

.24

.17

.17

.12

.12

7.20

.23

.49

.12

Mean 

streamflow 

(«3/s)

22

23

23

23

22

22

22

22

21

20

18

18

19

18

18

20

21

21

21

21

21

22

22

22

23

23

23

28

29

28

...

656

21.9

29

18

Suspended sediment

Mean 

concentration 

(mg/L)

September

3

5

10

8

7

7

9

10

9

9

9

9

10

9

9

8

8

10

13

13

12

11

10

9

8

7

7

7

6

6

...

9

13

3

Discharge 

(ton/d)

.18

.31

.62

.50

.42

.42

.53

.59

.51

.49

.44

.44

.51

.44

.44

.43

.45

.57

.74

.74

.68

.65

.59

.53

.50

.43

.43

.53

.47

.45

...

15.03

.50

.74

.18

TOTAL FOR WATER YEAR 1994: 

STREAMFLOW--28.246 ft3/s 

SEDIMENT DBCHARGE--638.25 tons

TABLE 6 39
Table 7. Daily streamflow and suspended-sediment data for Clark Fork at Deer Lodge, Montana, October 1993 through 

September 1994

[Abbreviations: ft3/s, cubic feet per second; mg/L, milligrams per liter; ton/d, tons per day. Symbol: , no data]

Suspended sediment

Day

1

2

3

4

5

6

7

8

9

10

11

12

13

14

15

16

17

18

19

20

21

22

23

24

25

26

27

28

29

30

31

TOTAL

MEAN

MAX

MIN

Mean 

streamflow 

(ft3/s)

271

253

245

246

244

240

252

290

292

293

289

264

276

290

282

294

304

305

302

301

293

294

293

286

278

276

280

291

291

284

295

8,694

280

305

240

Mean 

concentration 

(mg/L)

October

5

5

5

5

5

5

5

6

6

6

6

6

6

6

7

7

7

7

7

7

6

6

6

6

7

8

9

10

9

8

7

_

6

10

5

Discharge 

(ton/d)

3.7

3.4

3.3

3.3

3.3

3.2

3.4

4.7

4.7

4.7

4.7

4.3

4.5

4.7

5.3

5.6

5.7

5.8

5.7

5.7

4.7

4.8

4.7

4.6

5.3

6.0

6.8

7.9

7.1

6.1

5.6

153.3

5.0

7.9

3.2

Mean 

streamflow 

(ft3/s)

1993

300

297

311

317

309

296

303

302

297

293

287

275

283

277

281

289

283

285

277

277

280

230

120

110

100

120

150

190

213

242

-

7,594

253

317

100

Suspended sediment

Mean 

concentration 

(mg/L)

November

7

8

8

8

8

8

8

8

8

8

8

8

9

10

11

10

10

9

9

9

9

9

9

9

9

10

11

14

18

25

10

25

7

Discharge 

(ton/d)

5.7

6.4

6.7

6.8

6.7

6.4

6.5

6.5

6.4

6.3

6.2

5.9

6.9

7.5

8.3

7.8

7.6

6.9

6.7

6.7

6.8

5.6

2.9

2.7

2.4

3.2

4.5

7.2

10

16

196.2

6.5

16

2.4

Mean 

streamflow 

(ft3/s)

272

286

280

282

266

260

261

275

283

282

282

279

260

268

263

261

257

230

220

220

220

230

230

240

250

250

240

240

250

260

252

7,949

256

286

220

Suspended sediment

Mean 

concentration 

(mg/L)

December

25

23

23

24

27

33

33

32

32

30

29

27

26

27

33

24

14

12

10

11

15

17

17

17

18

20

39

43

40

37

31

25

43

10

Discharge 

(ton/d)

18

18

17

18

19

23

23

24

24

23

22

20

18

20

23

17

9.7

7.5

5.9

6.5

8.9

11

11

11

12

13

25

28

27

26

21

550.5

18

28

5.9

40 Water-Quality, Bed-Sediment, and Biological Data (October 1993 through September 1994) and Statistical Summaries of Data for 

Streams in the Upper Clark Fork Basin, Montana.
Table 7. Daily streamflow and suspended-sediment data for Clark Fork at Deer Lodge, Montana, October 1993 through 

September 1994 (Continued)

Suspended sediment

Day

1

2

3

4

5

6

7

8

9

10

11

12

13

14

15

16

17

18

19

20

21

22

23

24

25

26

27

28

29

30

31

TOTAL

MEAN

MAX

MIN

Mean 

streamflow 

(«3/s)

251

248

248

250

248

238

216

242

236

233

231

231

233

239

243

243

243

242

243

239

237

236

235

238

232

230

240

227

228

221

202

7,323

236

251

202

Mean 

concentration 

(mg/L)

January

25

23

23

24

25

25

25

24

23

21

20

20

21

23

21

20

19

18

18

18

18

19

20

20

21

21

21

22

22

23

23

...

21

25

18

Discharge 

(ton/d)

17

15

15

16

17

16

15

16

15

13

12

12

13

15

14

13

12

12

12

12

12

12

13

13

13

13

14

13

14

14

13

426

14

17

12

Mean 

streamflow 

(tf/s)

1994

190

200

210

210

200

180

130

100

110

130

140

160

190

204

216

227

238

238

239

219

223

224

223

228

222

232

228

228

...

...

5,539

198

239

100

Suspended sediment

Mean 

concentration 

(mg/L)

February

23

18

13

11

12

15

18

20

20

21

21

22

22

22

30

34

29

28

58

35

26

24

20

16

14

26

25

25

...

...

...

...

23

58

11

Discharge 

(ton/d)

12

9.7

7.4

6.2

6.5

7.3

6.3

5.4

5.9

7.4

7.9

9.5

11

12

17

21

19

18

37

21

16

15

12

9.8

8.4

16

15

15

...

...

354.7

13

37

5.4

Mean 

streamflow 

(«3/s)

253

291

282

281

276

261

250

245

239

233

233

228

230

237

231

243

238

235

222

209

213

207

209

208

214

219

219

221

222

219

217

7,285

235

291

207

Suspended sediment

Mean 

concentration 

(mg/L)

March

38

60

46

34

40

30

26

27

23

21

20

20

19

26

23

25

22

21

18

20

18

21

20

22

26

22

23

20

20

22

23

...

26

60

18

Discharge 

(ton/d)

26

47

35

26

30

21

18

18

15

13

13

12

12

17

14

16

14

13

11

11

10

12

11

12

15

13

14

12

12

13

13

519

17

47

10

TABLE 7 41
Table 7. Daily streamflow and suspended-sediment data for Clark Fork at Deer Lodge, Montana, October 1993 through 

September 1994 (Continued)

Suspended sediment

Day

1

2

3

4

5

6

7

8

9

10

11

12

13

14

15

16

17

18

19

20

21

22

23

24

25

26

27

28

29

30

31

TOTAL

MEAN

MAX

MIN

Mean 

streamflow 

(ft3/s)

215

224

233

256

255

254

267

277

269

256

254

252

254

244

238

238

239

244

264

298

322

357

398

418

431

412

388

381

382

376

...

8,896

297

431

215

Mean 

concentration 

(mg/L)

April

23

23

25

30

31

29

36

37

35

27

35

32

25

21

22

24

26

27

42

57

75

125

148

116

100

69

53

47

48

45

...

_

48

148

21

Discharge 

(ton/d)

13

14

16

21

21

20

26

28

25

19

24

22

17

14

14

15

17

18

30

46

65

120

159

131

116

77

56

48

50

46

...

1,288

43

159

13

Mean 

streamflow

(ft3/8)

1994

361

352

353

347

354

357

343

339

346

360

377

399

445

396

337

320

321

346

373

405

376

354

362

324

304

313

329

349

302

293

274

10,811

349

445

274

Suspended sediment

Mean 

concentration 

(mg/L)

May

41

44

45

38

34

33

42

37

39

48

55

66

75

60

41

32

38

62

71

37

34

30

27

26

25

23

25

25

22

17

17

...

39

75

17

Discharge 

(ton/d)

40

42

43

36

32

32

39

34

36

47

56

71

90

64

37

28

33

58

72

40

35

29

26

23

21

19

22

24

18

13

13

1,173

38

90

13

Mean 

streamflow

(«3/8)

277

300

306

290

265

245

221

204

192

161

143

139

154

210

231

246

235

214

195

180

156

154

158

142

124

115

99

93

83

82

_.

5,614

187

306

82

Suspended sediment

Mean 

concentration 

(mg/L)

June

18

18

16

15

14

22

14

7

6

5

5

5

7

17

16

14

12

10

9

8

8

10

7

6

9

22

32

38

41

43

...

15

43

5

Discharge 

(ton/d)

13

15

13

12

10

15

8.4

3.9

3.1

2.2

1.9

1.9

2.9

9.6

10

9.3

7.6

5.8

4.7

3.9

3.4

4.2

3.0

2.3

3.0

6.8

8.6

9.5

9.2

9.5

212.7

7.1

15

1.9

42 Water-Quality, Bed-Sediment, and Biological Data (October 1993 through September 1994) and Statistical Summaries of Data for 

Streams in the Upper Clark Fork Basin, Montana.
Table 7. Daily streamflow and suspended-sediment data for Clark Fork at Deer Lodge, Montana, October 1993 through 

September 1994 (Continued)

Suspended sediment

Day

1

2

3

4

5

6

7

8

9

10

11

12

13

14

15

16

17

18

19

20

21

22

23

24

25

26

27

28

29

30

31

TOTAL

MEAN

MAX

MIN

Mean 

streamflow 

(«3/s)

80

78

74

70

71

114

169

167

169

159

128

121

112

100

97

88

79

67

61

57

54

50

42

32

29

26

29

33

36

37

38

2,467

79.6

169

26

Mean 

concentration 

(mg/L)

July

39

35

33

33

35

42

33

20

17

16

13

9

9

9

9

8

7

7

6

5

6

7

9

10

11

16

18

19

21

20

24

...

18

42

5

Discharge 

(ton/d)

8.4

7.4

6.6

6.2

6.7

13

15

9.0

7.8

6.9

4.5

2.9

2.7

2.4

2.4

1.9

1.5

1.3

.99

.77

.87

.95

1.0

.86

.86

1.1

1.4

1.7

2.0

2.0

2.5

123.60

4.0

15

.77

Mean 

streamflow 

(ft3/s)

36

36

35

32

30

30

38

37

30

26

27

29

30

31

29

28

27

36

33

39

40

43

45

45

46

47

45

47

42

41

45

1,125

36.3

47

26

Suspended sediment

Mean 

concentration 

(mg/L)

1994

August

29

25

22

22

22

22

28

31

27

23

21

19

16

14

12

10

21

36

32

34

32

25

20

17

16

15

13

14

19

16

11

...

21

36

10

Discharge 

(ton/d)

2.8

2.4

2.1

1.9

1.8

1.8

2.9

3.1

2.2

1.6

1.5

1.5

1.3

1.2

.94

.76

1.5

3.5

2.9

3.6

3.5

2.9

2.4

2.1

2.0

1.9

1.6

1.8

2.2

1.8

1.3

64.80

2.1

3.6

.76

Mean 

streamflow 

(ft3/s)

50

50

65

73

76

76

73

71

62

62

71

73

68

67

72

74

74

75

80

94

93

95

100

105

106

96

96

91

112

117

...

2,417

80.6

117

50

Suspended sediment

Mean 

concentration 

(mg/L)

September

9

7

6

6

6

8

20

17

11

9

8

8

7

7

7

6

7

9

13

13

13

12

11

10

8

7

8

7

8

8

...

9

20

6

Discharge 

(ton/d)

1.2

.95

1.1

1.2

1.2

1.6

3.9

3.3

1.8

1.5

1.5

1.6

1.3

1.3

1.4

1.2

1.4

1.8

2.8

3.3

3.3

3.1

3.0

2.8

2.3

1.8

2.1

1.7

2.4

2.5

60.35

2.0

3.9

.95

TOTAL FOR WATER YEAR 1994: 

STREAMFLOW-75,714 ft3/s 

SEDIMENT DISCHARGE-5,122.15 tons

TABLE 7 43
Table 8. Daily streamflow and suspended-sediment data for Clark Fork at Turah Bridge, near Bonner, Montana, October 1993 

through September 1994

[Abbreviations: ftVs, cubic feet per second; mg/L, milligrams per liter, ton/d, tons per day. Symbol: , no data]

Suspended sediment

Day

1

2

3

4

5

6

7

g

9

10

11

12

13

14

15

16

17

18

19

20

21

22

23

24

25

26

27

28

29

30

31

TOTAL

MEAN

MAX

MIN

Mean 

streamflow 

(ft3/s)

1,140

1,130

1,090

1,070

1,050

1,040

1,100

uoo

1,200

1,170

1,180

1,190

1,150

1,160

1,210

1,210

uoo

1,200

1,190

1,180

1,180

1,160

1,140

1,110

1,100

1,070

1,060

1,090

1,140

1,080

1,060

35,250

1,137

1,210

1,040

Mean 

concentration 

(mg/L)

October

4

4

5

5

5

6

6

5

5

4

4

4

4

4

5

6

5

5

5

5

4

4

4

4

4

4

5

5

5

4

4

_

5

6

4

Discharge 

(ton/d)

12

12

15

14

14

17

18

16

16

13

13

13

12

13

16

20

16

16

16

16

13

13

12

12

12

12

14

15

15

12

11

439

14

20

11

Mean 

streamflow 

(ft3/s)

1993

1,110

1,100

1,090

1,110

1,110

1,060

1,040

1,070

1,050

1,020

1,030

989

967

971

935

977

988

976

970

932

933

960

600

450

450

450

500

600

800

950

27,188

906

1,110

450

Suspended sediment

Mean 

concentration 

(mg/L)

November

4

4

5

5

5

5

5

5

4

4

5

5

5

5

5

5

5

4

4

5

6

6

5

10

32

19

14

12

13

21

8

32

4

Discharge 

(ton/d)

12

12

15

15

15

14

14

14

11

11

14

13

13

13

13

13

13

11

10

13

15

16

8.1

12

39

23

19

19

28

54

492.1

16

54

8.1

Mean 

streamflow 

(ft3/s)

1,000

1,000

1,000

1,000

989

916

797

878

1,000

962

960

979

916

853

865

892

880

826

784

773

755

791

750

700

650

700

750

750

700

750

820

26,386

851

1,000

650

Suspended sediment

Mean 

concentration 

(mg/L)

December

21

14

11

10

9

8

8

9

10

9

8

8

8

8

8

8

8

8

13

10

7

10

11

11

11

11

11

10

11

13

17

...

10

21

7

Discharge 

(ton/d)

57

38

30

27

24

20

17

21

27

23

21

21

20

18

19

19

19

18

28

21

14

21

22

21

19

21

22

20

21

26

38

733

24

57

14

44 Water-Quality, Bed-Sediment, and Biological Data (October 1993 through September 1994) and Statistical Summaries of Data for 

Streams in the Upper Clark Fork Basin, Montana.
Table 8. Daily streamflow and suspended-sediment data for Clark Fork at Turah Bridge, near Bonner, Montana, October 1993 

through September 1994 (Continued)

Suspended sediment

Day

l

2

3

4

5

6

7

8

9

10

11

12

13

14

15

16

17

18

19

20

21

22

23

24

25

26

27

28

29

30

31

TOTAL

MEAN

MAX

MIN

Mean 

streamflow 

(ft3/s)

875

858

845

850

867

849

750

770

844

838

826

831

833

848

893

886

849

840

842

840

809

786

804

809

801

764

787

786

736

700

650

25,266

815

893

650

Mean 

concentration 

(mg/L)

January

19

16

14

11

9

7

6

7

10

13

17

21

23

24

25

25

23

20

17

13

11

10

9

10

13

14

14

12

10

7

6

_

14

25

6

Discharge 

(ton/d)

45

37

32

25

21

16

12

15

23

29

38

47

52

55

60

60

53

45

39

29

24

21

20

22

28

29

30

25

20

13

11

976

31

60

11

Mean 

streamflow 

(tf/s)

1994

550

550

600

650

600

600

550

450

500

550

650

700

700

700

700

720

729

774

739

727

716

723

707

706

596

538

671

750

...

-

18,146

648

774

450

Suspended sediment

Mean 

concentration 

(mg/L)

February

7

8

9

8

5

3

2

3

6

9

12

15

18

19

18

16

13

12

12

11

12

13

13

11

9

9

15

25

...

-

11

25

2

Discharge 

(ton/d)

10

12

15

14

8.1

4.9

3.0

3.6

8.1

13

21

28

34

36

34

31

26

25

24

22

23

25

25

21

14

13

27

51

...

571.7

20

51

3.0

Mean 

streamflow 

(ft3/s)

813

1,210

1,370

1,240

1,130

1,010

910

862

838

817

823

812

803

823

847

865

880

870

852

839

808

811

784

777

745

766

778

780

780

763

765

27,171

876

1,370

745

Suspended sediment

Mean 

concentration 

(mg/L)

March

44

150

180

130

65

38

25

22

21

21

20

20

21

19

19

24

28

25

21

18

16

15

13

9

8

10

13

12

12

13

14

...

34

180

8

Discharge 

(ton/d)

97

490

666

435

198

104

61

51

48

46

44

44

46

42

43

56

67

59

48

41

35

33

28

19

16

21

27

25

25

27

29

2,971

96

666

16

TABLE 8 45
Table 8. Daily streamflow and suspended-sediment data for Clark Fork at Turah Bridge, near Bonner, Montana, October 1993 

through September 1994 (Continued)

Suspended sediment

Day

1

2

3

4

5

6

1

8

9

10

11

12

13

14

15

16

17

18

19

20

21

22

23

24

25

26

27

28

29

30

31

TOTAL

MEAN

MAX

MIN

Mean 

streamflow 

(tf/s)

785

813

839

923

962

968

989

1,000

991

977

973

990

1,040

1,060

1,040

1,020

1,070

1,190

1,390

1,650

1,970

2,400

2,870

3,030

3,370

3,200

2,880

2,650

2,430

2,290

47,760

1,592

3,370

785

Mean 

concentration 

(mg/L)

April

16

21

28

42

53

44

48

44

41

37

32

31

38

44

32

32

43

58

110

155

185

195

195

162

160

100

64

60

54

46

_

72

195

16

Discharge 

(ton/d)

34

46

63

105

138

115

128

119

110

98

84

83

107

126

90

88

124

186

413

691

984

1,260

1,510

1,330

1,460

864

498

429

354

284

11,921

397

1,510

34

Mean 

streamflow 

(ft3/s)

1994

2,240

2,130

2,020

1,930

1,990

2,100

2,080

2,170

2,350

2,520

2,610

2,670

2,820

2,590

2,290

2,110

2,010

2,170

2,310

2,610

2,530

2,360

2,320

2,220

2,050

1,970

2,050

2,390

2,340

2,250

2,080

70,280

2,267

2,820

1,930

Suspended sediment

Mean 

concentration 

(mg/L)

May

45

44

39

37

40

44

46

50

54

60

63

63

68

67

46

29

28

34

42

54

45

38

32

26

24

24

25

39

37

25

18

41

68

18

Discharge 

(ton/d)

272

253

213

193

215

249

258

293

343

408

444

454

518

469

284

165

152

199

262

381

307

242

200

156

133

128

138

252

234

152

101

8,068

260

518

101

Mean 

streamflow 

(tf/s)

1,990

2,000

1,910

1,850

1,780

1,660

1,640

1,620

1,540

1,460

1,360

1,320

1,400

1,780

1,860

1,720

1,730

1,630

1,500

1,380

1,270

1,200

1,160

1,110

1,050

1,000

969

927

883

843

43,542

1,451

2,000

843

Suspended sediment

Mean 

concentration 

(mg/L)

June

17

19

19

16

14

13

12

11

9

8

8

9

10

26

24

12

10

9

8

6

6

7

8

7

7

8

7

6

6

7

11

26

6

Discharge 

(ton/d)

91

103

98

80

67

58

53

48

37

32

29

32

38

125

121

56

47

40

32

22

21

23

25

21

20

22

18

15

14

16

1,404

47

125

14

46 Water-Quality, Bed-Sediment, and Biological Data (October 1993 through September 1994) and Statistical Summaries of Data for 

Streams in the Upper Clark Fork Basin, Montana.
Table 8. Daily streamflow and suspended-sediment data for Clark Fork at Turah Bridge, near Bonner, Montana, October 1993 

through September 1994 (Continued)

Suspended sediment

Day

1

2

3

4

5

6

7

8

9

10

11

12

13

14

15

16

17

18

19

20

21

22

23

24

25

26

27

28

29

30

31

TOTAL

MEAN

MAX

MIN

Mean 

streamflow 

(ft3/s)

790

762

754

728

715

813

1,070

1,020

955

939

905

895

885

847

817

784

743

707

679

646

613

577

554

563

584

585

562

543

529

525

523

22,612

729

1,070

523

Mean 

concentration 

(mg/L)

July

6

5

5

5

5

6

16

15

14

12

9

8

9

8

7

7

7

7

7

7

7

7

7

7

6

7

6

5

5

6

7

_

8

16

5

Discharge 

(ton/d)

13

10

10

9.8

9.7

13

46

41

36

30

22

19

22

18

15

15

14

13

13

12

12

11

10

11

9.5

11

9.1

7.3

7.1

8.5

9.9

487.9

16

46

7.1

Mean 

streamflow 

(ft3*)

521

502

472

459

471

461

445

432

424

406

387

395

385

367

351

339

337

329

321

316

315

312

315

317

320

316

315

302

308

310

308

11,558

373

521

302

Suspended sediment

Mean 

concentration 

(mg/L)

1994

August

6

6

6

6

7

7

7

6

5

5

4

4

4

4

4

4

4

4

3

3

4

4

4

4

4

4

3

3

4

5

5

...

5

7

3

Discharge 

(ton/d)

8.4

8.1

7.6

7.4

8.9

8.7

8.4

7.0

5.7

5.5

4.2

4.3

4.2

4.0

3.8

3.7

3.6

3.6

2.6

2.6

3.4

3.4

3.4

3.4

3.5

3.4

2.6

2.4

3.3

4.2

4.2

149.5

4.8

8.9

2.4

Mean 

streamflow 

(ft3/s)

307

309

304

320

344

356

363

351

328

321

324

345

355

352

346

354

361

363

370

384

382

382

384

397

391

390

392

3%

394

421

10,786

360

421

304

Suspended sediment

Mean 

concentration 

(mg/L)

September

4

3

2

3

5

6

6

5

4

3

3

4

5

6

6

6

5

6

6

7

7

7

7

7

7

8

8

8

9

9

6

9

2

Discharge 

(ton/d)

3.3

2.5

1.6

2.6

4.6

5.8

5.9

4.7

3.5

2.6

2.6

3.7

4.8

5.7

5.6

5.7

4.9

5.9

6.0

7.3

7.2

7.2

7.3

7.5

7.4

8.4

8.5

8.6

9.6

10

171.0

5.7

10

1.6

TOTAL FOR WATER YEAR 1994: 

STREAMFLOW-365,945 ft3/s 

SEDIMENT DISCHARGE-28,3 84.2 tons

TABLE 8 47
Table 9. Daily streamflow and suspended-sediment data for Blackfoot River near Bonner, Montana, October 1993 through 

September 1994

[Abbreviations: ftVs, cubic feet per second; mg/L, milligrams per liter; ton/d, tons per day. Symbol: , no data]

Suspended sediment

Day

1

2

3

4

5

6

7

8

9

10

11

12

13

14

15

16

17

18

19

20

21

22

23

24

25

26

27

28

29

30

31

TOTAL

MEAN

MAX

MIN

Mean 

streamflow 

(ft3/s)

775

768

767

763

757

759

826

828

808

789

111

762

751

744

744

739

731

721

719

722

714

708

707

705

701

703

707

720

734

714

709

23,072

744

828

701

Mean 

concentration 

(mg/L)

October

3

3

3

2

2

3

4

2

1

2

2

2

2

2

2

2

2

2

3

3

3

3

3

3

3

3

3

2

2

2

1

_

2

4

1

Discharge 

(ton/d)

6.3

6.2

6.2

4.1

4.1

6.1

8.9

4.5

2.2

4.3

4.2

4.1

4.1

4.0

4.0

4.0

3.9

3.9

5.8

5.8

5.8

5.7

5.7

5.7

5.7

5.7

5.7

3.9

4.0

3.9

1.9

150.4

4.9

8.9

1.9

Mean 

streamflow 

(ft3/s)

1993

726

721

721

733

722

698

704

703

698

692

682

665

670

657

663

663

669

680

663

636

640

621

363

250

250

250

300

400

450

500

...

17,790

593

733

250

Suspended sediment

Mean 

concentration 

(mg/L)

November

2

2

2

2

2

1

1

2

2

2

2

2

2

2

2

2

2

2

2

2

2

2

2

2

2

2

2

2

3

3

2

3

1

Discharge 

(ton/d)

3.9

3.9

3.9

4.0

3.9

1.9

1.9

3.8

3.8

3.7

3.7

3.6

3.6

3.5

3.6

3.6

3.6

3.7

3.6

3.4

3.5

3.4

2.0

1.4

1.4

1.4

1.6

2.2

3.6

4.1

95.2

3.2

4.1

1.4

Mean 

streamflow 

(f»3/s)

550

550

550

550

520

500

480

500

560

540

520

520

500

480

450

470

500

480

450

450

430

420

400

390

380

380

400

400

400

420

450

14,590

471

560

380

Suspended sediment

Mean 

concentration 

(mg/1.)

December

3

2

2

2

3

3

3

3

2

2

2

2

2

3

3

3

3

3

3

3

4

6

7

7

6

3

2

1

1

1

1

3

7

1

Discharge 

(ton/d)

4.5

3.0

3.0

3.0

4.2

4.1

3.9

4.1

3.0

2.9

2.8

2.8

2.7

3.9

3.6

3.8

4.1

3.9

3.6

3.6

4.6

6.8

7.6

7.4

6.2

3.1

2.2

1.1

1.1

1.1

1.2

112.9

3.6

7.6

1.1

48 Water-Quality, Bed-Sediment, and Biological Data (October 1993 through September 1994) and Statistical Summaries of Data for 

Streams in the Upper Clark Fork Basin, Montana.
Table 9. Daily streamflow and suspended-sediment data for Blackfoot River near Bonner, Montana, October 1993 through 

September 1994 (Continued)

Suspended sediment

Day

1

2

3

4

5

6

7

8

9

10

11

12

13

14

15

16

17

18

19

20

21

22

23

24

25

26

27

28

29

30

31

TOTAL

MEAN

MAX

MIN

Mean 

streamflow 

(ft3/*)

480

480

480

480

470

450

430

450

480

480

480

480

500

520

550

520

500

480

480

470

450

450

450

450

450

440

440

430

420

400

380

14,420

465

550

380

Mean 

concentration 

(mg/L)

January

1

1

2

2

2

2

2

2

1

1

1

2

2

2

3

2

2

1

1

1

1

1

1

1

1

1

1

1

1

1

1

_

1

3

1

Discharge 

(ton/d)

1.3

1.3

2.6

2.6

2.5

2.4

2.3

2.4

1.3

1.3

1.3

2.6

2.7

2.8

4.5

2.8

2.7

1.3

1.3

1.3

1.2

1.2

1.2

1.2

1.2

1.2

1.2

1.2

1.1

1.1

1.0

56.1

1.8

4.5

1.0

Mean 

streamflow 

(ft3/s)

1994

350

370

400

400

380

350

250

200

220

250

300

350

400

450

470

480

500

520

500

490

480

480

470

470

450

450

470

500

...

...

...

11,400

407

520

200

Suspended sediment

Mean 

concentration 

(mg/L)

February

1

1

1

1

1

1

1

1

1

1

1

1

1

1

1

1

1

1

1

1

1

1

1

1

1

1

1

1

...

...

_

1

1

1

Discharge 

(ton/d)

.95

1.0

1.1

1.1

1.0

.95

.68

.54

.59

.68

.81

.95

1.1

1.2

1.3

1.3

1.4

1.4

1.4

1.3

1.3

1.3

1.3

1.3

1.2

1.2

1.3

1.4

31.05

1.1

1.4

.54

Mean 

streamflow 

(fl^s)

520

601

657

703

713

664

593

549

520

516

517

534

543

564

609

643

662

661

672

661

660

647

642

630

614

605

605

607

608

604

619

18,943

611

713

516

Suspended sediment

Mean 

concentration 

(mg/L)

March

4

11

7

11

13

10

5

3

2

2

3

2

2

3

5

6

4

4

7

6

5

4

4

4

3

3

3

3

3

4

4

...

5

13

2

Discharge 

(ton/d)

5.6

18

12

21

25

18

8.0

4.4

2.8

2.8

4.2

2.9

2.9

4.6

8.2

10

7.1

7.1

13

11

8.9

7.0

6.9

6.8

5.0

4.9

4.9

4.9

4.9

6.5

6.7

256.0

8.3

25

2.8

TABLE 9 49
Table 9. Daily streamflow and suspended-sediment data for Blackfoot River near Bonner, Montana, October 1993 through 

September 1994 (Continued)

Suspended sediment

Day

1

2

3

4

5

6

7

8

9

10

11

12

13

14

15

16

17

18

19

20

21

22

23

24

25

26

27

28

29

30

31

TOTAL

MEAN

MAX

MIN

Mean 

streamflow 

(It3/s)

647

686

764

913

986

1,020

1,060

1,070

1,050

1,040

1,060

1,110

1,210

1,270

1,290

1,320

1,430

1,850

2,500

3,330

4,060

4,890

5,520

5,800

5,830

5,360

4,740

4,190

3,750

3,420

._

73,166

2,439

5,830

647

Mean 

concentration 

(mg/L)

April

4

6

10

17

19

17

16

12

10

10

10

11

13

13

10

11

17

26

48

68

76

100

96

96

72

42

30

23

20

18

...

31

100

4

Discharge 

(ton/d)

7.0

11

21

42

51

47

46

35

28

28

29

33

42

45

35

39

66

130

324

611

833

1,320

1,430

1,500

1,130

608

384

260

202

166

...

9,503.0

317

1,500

7.0

Mean 

streamflow 

(fl3/s)

1994

3,200

3,000

2,870

2,790

2,780

2,870

3,110

3,510

4,000

4,470

4,780

5,000

5,200

4,850

4,360

4,090

3,880

3,730

3,610

3,600

3,590

3,440

3,280

3,160

3,140

3,180

3,410

3,620

3,490

3,340

3,030

112,380

3,625

5,200

2,780

Suspended sediment

Mean 

concentration 

(mg/L)

May

16

15

12

10

11

13

14

21

31

42

45

47

48

42

32

23

20

16

16

16

14

12

11

11

12

12

15

20

17

14

13

_

21

48

10

Discharge 

(ton/d)

138

121

93

75

83

101

118

199

335

507

581

634

674

550

377

254

210

161

156

156

136

111

97

94

102

103

138

195

160

126

106

6,891

222

674

75

Mean 

streamflow 

(tf/s)

2,850

2,790

2,680

2,670

2,650

2,570

2,620

2,530

2,380

2,190

2,050

1,960

1,990

2,160

2,140

2,020

1,960

1,890

1,780

1,690

1,590

1,510

1,450

1,380

1,310

1,270

1,250

1,210

1,140

1,090

58,770

1,959

2,850

1,090

Suspended sediment

Mean 

concentration 

(mg/L)

June

11

10

10

10

10

10

10

9

8

7

6

6

7

8

8

7

6

6

6

5

5

6

6

6

5

5

4

3

3

3

...

7

11

3

Discharge 

(ton/d)

85

75

72

72

72

69

71

61

51

41

33

32

38

47

46

38

32

31

29

23

21

24

23

22

18

17

13

9.8

9.2

8.8

1,183.8

39

85

8.8

50 Water-Quality, Bed-Sediment, and Biological Data (October 1993 through September 1994) and Statistical Summaries of Data for 

Streams in the Upper Clark Fork Basin, Montana.
Table 9. Daily streamflow and suspended-sediment data for Blackfoot River near Bonner, Montana, October 1993 through 

September 1994 (Continued)

Suspended sediment

Day

1

2

3

4

5

6

7

8

9

10

11

12

13

14

15

16

17

18

19

20

21

22

23

24

25

26

27

28

29

30

31

TOTAL

MEAN

MAX

MIN

Mean 

streamflow 

(ft3/s)

1,040

1,010

999

1,000

984

1,000

999

974

911

877

841

811

789

768

750

743

723

700

683

664

642

603

598

592

601

596

588

582

564

556

544

23,732

766

1,040

544

Mean 

concentration 

(mg/L)

July

5

5

5

4

4

4

4

4

4

4

4

4

3

3

3

3

3

3

3

3

3

3

3

3

3

3

2

2

2

2

3

_

3

5

2

Discharge 

(ton/d)

14

14

13

11

11

11

11

11

9.8

9.5

9.1

8.8

6.4

6.2

6.1

6.0

5.9

5.7

5.5

5.4

5.2

4.9

4.8

4.8

4.9

4.8

3.2

3.1

3.0

3.0

4.4

226.5

7.3

14

3.0

Mean 

streamflow 

(ft3/s)

545

539

530

532

524

515

507

509

498

481

475

468

468

462

452

438

429

420

417

415

414

419

422

410

402

397

391

387

391

394

412

14,063

454

545

387

Suspended sediment

Mean 

concentration 

(mg/L)

1994

August

3

3

3

3

2

2

2

2

2

2

2

2

2

2

2

2

2

2

2

2

1

2

2

2

2

2

2

2

2

2

2

...

2

3

1

Discharge 

(ton/d)

4.4

4.4

4.3

4.3

2.8

2.8

2.7

2.7

2.7

2.6

2.6

2.5

2.5

2.5

2.4

2.4

2.3

2.3

2.3

2.2

1.1

2.3

2.3

2.2

2.2

2.1

2.1

2.1

2.1

2.1

2.2

80.5

2.6

4.4

1.1

Mean 

streamflow 

(ft3/s)

404

404

403

416

418

419

419

408

394

389

392

394

391

385

388

385

388

387

385

388

387

379

380

382

383

379

378

375

373

375

11,748

392

419

373

Suspended sediment

Mean 

concentration 

(mg/L)

September

2

2

2

2

2

2

2

2

2

2

2

2

2

2

2

2

2

2

2

2

2

2

2

2

3

3

3

3

3

3

2

3

2

Discharge 

(ton/d)

2.2

2.2

2.2

2.2

2.3

2.3

2.3

2.2

2.1

2.1

2.1

2.1

2.1

2.1

2.1

2.1

2.1

2.1

2.1

2.1

2.1

2.0

2.1

2.1

3.1

3.1

3.1

3.0

3.0

3.0

69.7

2.3

3.1

2.0

TOTAL FOR WATER YEAR 1994: 

STREAMFLOW-394,074 ft3/s 

SEDIMENT DISCHARGE-18,656 tons

TABLE 9 51
Table 10. Daily streamflow and suspended-sediment data for Clark Fork above Missoula, Montana, October 1993 through 

September 1994

[Abbreviations: ft3/s, cubic feet per second;; mg/L, milligrams per liter; ton/d, tons per day. Symbol: , no data]

Suspended sediment

Day

1

2

3

4

5

6

7

8

9

10

11

12

13

14

15

16

17

18

19

20

21

22

23

24

25

26

27

28

29

30

31

TOTAL

MEAN

MAX

MIN

Mean 

streamflow 

(ft3/s)

1,820

1,800

1,780

1,760

1,700

1,730

1,830

1,930

1,930

1,890

1,860

1,870

1,830

1,800

1,910

1,890

,850

,850

,830

,840

,820

,800

,760

1,740

1,710

1,700

1,740

1,730

1,800

1,750

1,710

55,960

1,805

1,930

1,700

Mean 

concentration 

(mg/L)

October

6

6

6

6

6

7

7

5

4

3

3

4

4

5

5

6

6

5

4

4

4

4

3

3

3

3

4

3

3

3

3

_

4

7

3

Discharge 

(ton/d)

29

29

29

29

28

33

35

26

21

15

15

20

20

24

26

31

30

25

20

20

20

19

14

14

14

14

19

14

15

14

14

676

22

35

14

Mean 

streamflow

(ft3*)

1993

1,770

1,770

1,740

1,790

1,780

1,730

1,670

1,730

1,710

1,670

1,660

1,650

1,600

1,610

1,540

1,610

1,610

1,640

1,580

1,540

1,550

1,510

900

700

700

700

800

1,000

1,200

1,500

43,960

1,465

1,790

700

Suspended sediment

Mean 

concentration 

(mg/L)

November

3

3

4

4

4

4

4

4

3

3

3

3

2

3

3

3

3

3

3

3

3

3

4

4

4

4

6

7

6

5

...

4

7

2

Discharge 

(ton/d)

14

14

19

19

19

19

18

19

14

14

13

13

8.6

13

12

13

13

13

13

12

13

12

9.7

7.6

7.6

7.6

13

19

19

20

421.1

14

20

7.6

Mean 

streamflow 

(ft3/s)

1,600

1,600

1,600

1,600

1,590

1,430

1,340

1,390

1,640

1,550

1,490

1,540

1,460

1,370

1,320

1,410

1,440

1,380

1,300

1,300

1,230

1,240

1,200

1,150

1,100

1,100

1,200

1,200

1,150

1,200

1,300

42,420

1,368

1,640

1,100

Suspended sediment

Mean 

concentration 

(mg/L)

December

4

4

4

5

4

3

3

4

4

4

4

4

4

4

4

5

6

7

11

6

4

3

4

5

7

5

3

3

4

4

4

...

5

11

3

Discharge 

(ton/d)

17

17

17

22

17

12

11

15

18

17

16

17

16

15

14

19

23

26

39

21

13

10

13

16

21

15

9.7

9.7

12

13

14

515.4

17

39

9.7

52 Water-Quality, Bed-Sediment, and Biological Data (October 1993 through September 1994) and Statistical Summaries of Data for 

Streams in the Upper Clark Fork Basin, Montana.
Table 10. Daily streamflow and suspended-sediment data for Clark Fork above Missoula, Montana, October 1993 through 

September 1994 (Continued)

Suspended sediment

Day

1

2

3

4

5

6

7

8

9

10

11

12

13

14

15

16

17

18

19

20

21

22

23

24

25

26

27

28

29

30

31

TOTAL

MEAN

MAX

MIN

Mean 

streamflow 

(ftS/s)

1,400

1,360

1390

1,370

1,410

1,370

1,270

1,260

1,390

1,360

1,360

1,370

1,370

1,400

1,490

1,460

1,420

1,370

1,380

1,380

1,330

1,270

1,270

1,300

1,300

1,270

1,260

1,270

1,220

1,190

1,090

41,350

1,334

1,490

1,090

Mean 

concentration 

(mg/L)

January

5

5

5

4

4

4

4

4

5

6

6

7

7

8

9

10

8

6

5

4

4

3

4

5

6

6

5

5

5

4

4

_

5

10

3

Discharge 

(ton/d)

19

18

19

15

15

15

14

14

19

22

22

26

26

30

36

39

31

22

19

15

14

10

14

18

21

21

17

17

16

13

12

609

20

39

10

Mean 

streamflow 

(ft3/s)

1994

950

950

1,000

1,100

1,000

1,000

800

650

700

800

900

1,100

1,150

1,200

1,200

1,200

1,250

1,330

1,260

1,220

1,180

1,180

1,150

1,150

1,000

1,000

1,110

1,220

...

...

29,750

1,063

1,330

650

Suspended sediment

Mean 

concentration 

(mg/L)

February

3

3

3

3

3

3

3

4

5

6

5

4

4

4

4

4

4

6

7

7

6

5

5

5

7

7

7

7

...

...

-

_

5

7

3

Discharge 

(ton/d)

7.7

7.7

8.1

8.9

8.1

8.1

6.5

7.0

9.5

13

12

12

12

13

13

13

13

22

24

23

19

16

16

16

19

19

21

23

...

390.6

14

24

6.5

Mean 

streamflow 

(ft3/s)

1,300

1,800

2,080

2,020

1,940

1,740

1,570

1,430

1,400

1,360

1,370

1,380

1,360

1,400

1,490

1,490

1,580

1,560

1,540

1,520

1,500

1,490

1,460

1,430

1,360

1,380

1,390

1,430

1,400

1,380

1,370

46,920

1,514

2,080

1,300

Suspended sediment

Mean 

concentration 

(mg/L)

March

6

10

50

44

22

14

10

8

8

8

8

8

7

8

8

9

10

10

9

8

8

8

8

7

7

8

8

8

6

6

8

...

11

50

6

Discharge 

(ton/d)

21

49

281

240

115

66

42

31

30

29

30

30

26

30

32

36

43

42

37

33

32

32

32

27

26

30

30

31

23

22

30

1,558

50

281

21

TABLE 10 53
Table 10. Daily streamflow and suspended-sediment data for Clark Fork above Missoula, Montana, October 1993 through 

September 1994 (Continued)

Suspended sediment

Day

1

2

3

4

5

6

7

8

9

10

11

12

13

14

15

16

17

18

19

20

21

22

23

24

25

26

27

28

29

30

31

TOTAL

MEAN

MAX

MIN

Mean 

streamflow 

(ft3/s)

1,440

1,500

1,590

1,850

1,960

2,010

2,050

2,070

2,050

2,030

2,030

2,080

2,210

2,340

2,330

2,320

2,460

2,920

3,800

4,870

5,920

7,180

8,290

8,760

9,060

8,490

7,550

6,730

6,140

5,610

--

119,640

3,988

9,060

1,440

Mean 

concentration 

(mg/L)

April

12

11

10

12

15

12

12

12

12

15

14

12

10

12

11

12

14

16

33

38

54

68

88

90

76

56

36

28

26

25

_

28

90

10

Discharge 

(ton/d)

47

45

43

60

79

65

66

67

66

82

77

67

60

76

69

75

93

126

339

500

863

1,320

1,970

2,130

1,860

1,280

734

509

431

379

13,578

453

2,130

43

Mean 

streamflow 

(ft3/s)

1994

5,370

5,060

4,840

4,670

4,670

4,860

5,070

5,550

6,200

6,820

7,280

7,510

7,880

7,420

6,590

6,200

5,840

5,860

5,830

6,120

6,040

5,740

5,510

5,310

5,120

5,070

5,330

5,920

5,780

5,530

5,080

180,070

5,809

7,880

4,670

Suspended sediment

Mean 

concentration 

(mg/L)

May

23

23

21

20

20

20

21

24

28

34

39

42

45

40

31

24

23

20

19

23

22

19

16

16

14

13

14

20

19

15

14

_

23

45

13

Discharge 

(ton/d)

333

314

274

252

252

262

287

360

469

626

767

852

957

801

552

402

363

316

299

380

359

294

238

229

194

178

201

320

297

224

192

11,844

382

957

178

Mean 

streamflow 

(tf/s)

4,810

4,750

4,560

4,480

4,410

4,210

4,230

4,150

3,910

3,640

3,400

3,250

3,360

3,890

3,990

3,720

3,680

3,510

3,290

3,040

2,840

2,680

2,560

2,460

2,330

2,220

2,190

2,130

2,000

1,920

101,610

3,387

4,810

1,920

Suspended sediment

Mean 

concentration 

(mg/L)

June

14

13

13

12

12

12

12

11

11

10

10

10

10

11

15

14

12

10

9

9

9

10

10

10

9

8

8

8

9

9

_.

11

15

8

Discharge 

(ton/d)

182

167

160

145

143

136

137

123

116

98

92

88

91

116

162

141

119

95

80

74

69

72

69

66

57

48

47

46

49

47

3,035

101

182

46

54 Water-Quality, Bed-Sediment, and Biological Data (October 1993 through September 1994) and Statistical Summaries of Data for 

Streams in the Upper Clark Fork Basin, Montana.
Table 10. Daily streamflow and suspended-sediment data for Clark Fork above Missoula, Montana, October 1993 through 

September 1994 (Continued)

Suspended sediment

Day

1

2

3

4

5

6

7

8

9

10

11

12

13

14

15

16

17

18

19

20

21

22

23

24

25

26

27

28

29

30

31

TOTAL

MEAN

MAX

MIN

Mean 

streamflow 

(ft3/s)

1,830

1,740

1,720

1,720

1,700

1,760

2,030

2,000

1,870

1,800

1,730

1,690

1,640

1,610

1,550

1,510

1,480

1,410

1,370

1,300

1,270

1,200

1,150

1,150

1,180

1,190

1,160

1,130

1,110

1,090

1,070

46,160

1,489

2,030

1,070

Mean 

concentration 

(mg/L)

Juiy

9

8

8

8

7

7

9

9

9

8

8

7

9

9

8

7

7

7

9

8

7

6

6

6

6

7

7

7

7

7

6

8

9

6

Discharge 

(ton/d)

44

38

37

37

32

33

49

49

45

39

37

32

40

39

33

29

28

27

33

28

24

19

19

19

19

22

22

21

21

21

17

953

31

49

17

Mean 

streamflow 

(ft3/s)

1,070

1,060

1,030

1,020

1,010

1,000

940

932

940

937

906

891

891

867

845

820

808

808

782

111

757

769

778

774

768

763

742

738

740

753

764

26,680

861

1,070

738

Suspended sediment

Mean 

concentration 

(mg/L)

1994

August

5

5

5

5

5

5

5

5

5

5

5

5

5

5

5

5

5

6

5

5

5

4

5

5

4

4

4

4

4

3

3

...

5

6

3

Discharge 

(ton/d)

14

14

14

14

14

13

13

13

13

13

12

12

12

12

11

11

11

13

11

10

10

8.3

11

10

8.3

8.2

8.0

8.0

8.0

6.1

6.2

342.1

11

14

6.1

Mean 

streamflow 

(ft3/s)

760

754

754

799

809

 826

833

813

773

752

745

781

799

779

764

779

793

791

785

805

814

800

796

816

806

805

806

805

808

827

23,777

793

833

745

Suspended sediment

Mean 

concentration 

(mg/L)

September

3

3

3

4

3

3

3

3

3

3

3

3

3

4

3

3

3

3

3

3

3

3

3

3

3

3

3

3

3

3

...

3

4

3

Discharge 

(ton/d)

6.2

6.1

6.1

8.6

6.6

6.7

6.7

6.6

6.3

6.1

6.0

6.3

6.5

8.4

6.2

6.3

6.4

6.4

6.4

6.5

6.6

6.5

6.4

6.6

6.5

6.5

6.5

6.5

6.5

6.7

196.7

6.6

8.6

6.0

TOTAL FOR WATER YEAR 1994: 

STREAMFLOW-758,297 fWs 

SEDIMENT DISCHARGE-34,118.9 tons

TABLE 10 55
Table 11. Chemical analyses of field replicates for water samples, upper Clark Fork basin, Montana

[Abbreviations: ug/L, micrograms per liter; mg/L, milligrams per liter. Symbols: <, less than minimum reporting level; --, no data. Note-dissolved 

constituents processed through two different types of filters to evaluate differences in analytical results]

Station 

number

12323230

12323600

12323770

12323800

12324200

12324680

12331500

12331800

12334550

12340500

Station name

Blacktail Creek at Harrison Avenue, at Butte

Silver Bow Creek at Opportunity

Warm Springs Creek at Warm Springs

Clark Fork near Galen

Clark Fork at Deer Lodge

Clark Fork at Goldcreek

Flint Creek near Drummond

Clark Fork near Drummond

Clark Fork at Turah Bridge, near Bonner

Clark Fork above Missoula

Date

08-17-94

08-17-94

03-08-94

03-08-94

02-16-94

02-16-94

07-11-94

07-11-94

05-11-94

05-11-94

04-26-94

04-26-94

10-29-93

10-29-93

05-24-94

05-24-94

06-14-94

06-14-94

04-13-94

04-13-94

Time

0845

0850

1255

1300

0820

0825

1545

1550

1720

1725

1330

1335

1045

1045

1945

1950

1015

1020

0830

0835

Calcium, 

dissolved 

(mg/L)

39

38

45

45

58

58

57

56

45

46

36

36

39

38

51

51

34

34

35

36

Magnesium, 

dissolved 

(mg/L)

9.7

8.5

9.8

9.7

12

12

12

12

9.6

9.8

8.3

8.4

12

11

12

12

8.8

8.9

10

10

Sodium, 

dissolved 

(mg/L)

14

14

22

22

4.2

4.2

13

13

11

11

8.3

8.4

7.8

7.6

12

11

7.2

7.1

6.0

6.0

Potassium, 

dissolved 

(mg/L)

2.8

2.8

5.4

5.6

1.7

1.6

4.3

4.0

2.7

2.7

2.1

2.2

2.9

2.7

4.0

4.0

2.0

2.1

1.6

1.6

Alkalinity, 

(mg/L 

as 

CaC03)

117

116

101

99

132

136

105

105

102

102

95

95

147

146

136

136

107

107

115

116

Sulfate, 

dissolved 

(mg/L)

36

35

77

79

69

69

110

110

67

67

43

43

17

17

57

57

30

30

28

28

56 Water-Quality, Bed-Sediment, and Biological Data (October 1993 through September 1994) and Statistical Summaries of Data for 

Streams in the Upper Clark Fork Basin, Montana.
Table 11. Chemical analyses of field replicates for water samples, upper Clark Fork basin, Montana (Continued)

Station

number

12323230

12323600

12323770

12323800

12324200

12324680

12331500

12331800

12334550

12340500

Date

08-17-94

08-17-94

03-08-94

03-08-94

02-16-94

02-16-94

07-11-94

07-11-94

05-11-94

05-11-94

04-26-94

04-26-94

10-29-93

10-29-93

05-24-94

05-24-94

06-14-94

06-14-94

04-13-94

04-13-94

Chloride,

dissolved

(mg/L)

7.5

7.6

15

17

1.3

1.3

5.9

5.9

5.0

4.9

3.5

3.5

3.2

3.2

4.1

4.1

2.3

2.3

2.2

2.2

Fluoride,

dissolved

(mg/L)

0.3

.3

.5

.5

.4

.4

.7

.7

.5

.5

.3

.3

.2

.2

.4

.4

.2

.2

.2

.2

Silica,

dissolved

(mg/L)

28

28

26

25

13

13

11

11

13

13

18

18

21

21

20

20

16

16

12

12

Solids,

sum of 

constituents,

dissolved

(mg/L)

208

205

262

264

239

241

277

276

215

216

177

177

191

188

242

241

165

165

164

166

Arsenic, 

total

recoverable

(n9/L)

3

3

18

18

5

5

18

18

25

25

14

14

12

12

15

15

6

6

4

4

Cadmium, 

Arsenic, Cadmium, 

total

dis- disrecovsolved solved erabte

(ng/L)

3 <1 <0.1

3 <1 <.l

10 2 1.5

9 2 1.5

4 <1 <.l

4 <1 <.l

17 <1 <.l

17 <1 <.l

15 <1 <.l

15 <1 <.l

8 <1 < !

8 <1 < !

7 <1 <.l

7 <1 <.l

12 <1 <.l

11 <1 <-l

5 <1 <.l

5 <1 <.l

3 <1 <.l

3 <1 <.l

Copper, 

total

recoverable

(ng/L)

3

5

140

140

7

7

15

15

93

100

49

49

3

3

33

31

12

12

10

9

Copper,

dissolved

(iig/L)

l

5

60

54

2

2

10

10

11

13

6

6

<1

<l

7

7

3

4

2

2

TABLE 11 57
Table 11. Chemical analyses of field replicates for water samples, upper Clark Fork basin, Montana (Continued)

Station

number

12323230

12323600

12323770

12323800

12324200

12324680

12331500

12331800

12334550

12340500

Date

08-17-94

08-17-94

03-08-94

03-08-94

02-16-94

02-16-94

07-11-94

07-11-94

05-11-94

05-11-94

04-26-94

04-26-94

10-29-93

10-29-93

05-24-94

05-24-94

06-14-94

06-14-94

04-13-94

04-13-94

Iron,

total

recoverable

(H9/L)

310

300

860

840

110

120

150

170

1,400

1,500

1,700

1,600

420

420

700

690

390

380

270

260

iron,

dissolved

(M9/L)

24

65

30

13

8

7

6

53

10

49

43

86

14

24

9

28

16

18

19

38

Lead,

total Lead.

recov- dissolved

erable (n{J/L)

ML}

1 <0.5

2 <5

18 .7

18 .7

<1 <5

<1 <5

<1 <.5

<1 <.5

11 <-5

12 .8

9 <.5

8 .5

7 <-5

7 <.5

4 <.5

4 <-5

2 <.5

2 <.5

2 <.5

1 <.5

Manganese, 

total

recoverable

(ug/L)

100

100

630

630

170

180

100

100

300

300

230

210

120

110

100

110

50

50

50

50

Manganese,

dissolved

(ufl/L)

99

97

620

620

120

120

46

51

22

27

14

16

49

48

11

12

4

4

25

25

Zinc,

total

recoverable

(Mtl/L)

<10

<10

520

520

<10

<10

20

20

120

120

90

80

30

30

50

50

30

30

20

20

Zinc,

dissolved

(^g/L)

<3

4

380

380

7

<3

26

5

5

10

9

9

6

4

4

6

<3

<3

8

5

58 Water-Quality, Bed-Sediment, and Biological Data (October 1993 through September 1994) and Statistical Summaries of Data for 

Streams in the Upper Clark Fork Basin, Montana.
Table 12. Precision of chemical analyses of field replicates for water samples, upper 

Clark Fork basin, Montana

[Abbreviations: mg/L, milligrams per liter; ng/L, micrograms per liter]

Constituent and reporting unit

Calcium, dissolved, mg/L

Magnesium, dissolved, mg/L

Sodium, dissolved, mg/L

Potassium, dissolved, mg/L

Alkalinity, mg/L as CaCO3

Sulfate, dissolved, mg/L

Chloride, dissolved, mg/L

Fluoride, dissolved, mg/L

Silica, dissolved, mg/L

Arsenic, total recoverable, |ig/L

Arsenic, dissolved, ng/L

Cadmium, total recoverable, ng/L

Cadmium, dissolved, ng/L

Copper, total recoverable, \igfL

Copper, dissolved, |ig/L

Iron, total recoverable, \ig/L

Iron, dissolved, ng/L

Lead, total recoverable, \igfL

Lead, dissolved, ng/L

Manganese, total recoverable, ng/L

Manganese, dissolved, jig/L

Zinc, total recoverable, ng/L

Zinc, dissolved, |ig/L

Number off 

replicate pairs

10

10

10

10

10

10

10

10

10

10

10

10

10

10

10

10

10

10

10

10

10

10

10

Standard 

deviation, 

in units (+/-)

0.50

.24

.23

.10

1.1

.50

.45

.0

.22

.0

.32

.0

.0

1.7

1.7

33

20

.45

.43

5.9

1.7

2.2

5.1

Relative 

standard 

deviation, 

In percent (+/-)

1.1

2.3

2.2

3.4

1.0

.9

8.8

.0

1.2

.0

3.9

.0

.0

4.8

16

5.2

71

8.2

39

3.2

1.7

2.5

12

TABLE 12 59
Table 13. Precision of chemical analyses of laboratory replicates for water samples, upper Clark 

Fork basin, Montana

[Abbreviations: f4g/L, micrograms per liter; jiiS/cm, microsiemens per centimeter at 25 degrees Celsius; mg/L, milligrams per liter

Property or constituent and reporting unit

Specific conductance, uS/cm

pH, units

Calcium, dissolved, mg/L

Magnesium, dissolved, mg/L

Sodium, dissolved, mg/L

Potassium, dissolved, mg/L

Alkalinity, mg/L as CaCC>3

Sulfate, dissolved, mg/L

Chloride, dissolved, mg/L

Fluoride, dissolved, mg/L

Silica, dissolved, mg/L

Arsenic, total recoverable, ug/L

Arsenic, dissolved, ug/L

Cadmium, total recoverable, ug/L

Cadmium, dissolved, ug/L

Copper, total recoverable, ug/L

Copper, dissolved, ug/L

Iron, total recoverable, ug/L

Iron, dissolved, ug/L

Lead, total recoverable, ug/L

Lead, dissolved, ug/L

Manganese, total recoverable, ug/L

Manganese, dissolved, ug/L

Zinc, total recoverable, ug/L

Zinc, dissolved, ug/L

Number of 

replicate pairs

10

10

10

10

10

5

5

11

12

8

3

10

10

10

10

10

10

10

10

10

10

9

10

10

10

Standard 

deviation, 

in units (+/-)

7.2

.09

.63

.12

.28

.10

.32

.37

.20

.05

.22

.17

.34

.04

.0

.97

.28

12

1.5

.18

.02

2.8

6.2

1.8

11

Relative 

standard 

deviation, 

in percent (+/-)

2.4

1.2

1.7

1.4

2.3

2.8

.4

1.0

3.6

6.2

2.0

1.9

5.3

12

.0

3.2

2.6

2.4

2.5

3.1

6.2

1.6

2.4

1.7

5.1

Within limits 

of dataquality 

objective

Yes

Yes

Yes

Yes

Yes

Yes

Yes

Yes

Yes

Yes

Yes

Yes

Yes

Yes

Yes

Yes

Yes

Yes

Yes

Yes

Yes

Yes

Yes

Yes

Yes

60 Water-Quality, Bed-Sediment, and Biological Data (October 1993 through September 1994) and Statistical Summaries of Data for 

Streams in the Upper Clark Fork Basin, Montana.
Table 14. Recovery efficiency for trace-element analyses of laboratory-spiked deionized-water blanks

[Abbreviation: fJg/L, micrograms per liter]

Constituent and reporting unit

Number of 

samples

Mean spike 

recovery, 

in percent

95-percent 

confidence 

interval for 

spike recovery, 

in percent

Within limits 

of dataquality 

objective

Arsenic, total recoverable, \ig/L 

Arsenic, dissolved, \ig/L 

Cadmium, total recoverable, ng/L 

Cadmium, dissolved, \ig/L 

Copper, total recoverable, jig/L 

Copper, dissolved, \igfL 

Iron, total recoverable, \ig/L 

Iron, dissolved, |ig/L 

Lead, total recoverable, \ig/L 

Lead, dissolved, \\gfL 

Manganese, total recoverable, \\gfL 

Manganese, dissolved, jig/L 

Zinc, total recoverable, \\gfL 

Zinc, dissolved, |ag/L

109.3

100.6

98.8

97.5

99.7

101.1

100.0

94.6

99.1

100.5

95.7

101.5

102.6

106.5

104-114 

95.6-106 

90.6-107 

89.1-106 

94.3-105 

98.4-104 

93.0-107 

84.2-105 

94.3-104 

98.5-102 

90.8-100 

96.2-107 

91.5-114 

95.8-117

Yes 

Yes 

Yes 

Yes 

Yes 

Yes 

Yes 

Yes 

Yes 

Yes 

Yes 

Yes 

Yes 

Yes

TABLE 14 61
Table 15. Recovery efficiency for trace-element analyses of laboratory-spiked stream samples, 

upper Clark Fork basin, Montana

[Abbreviation: ng/L, micrograms per liter]

Constituent

Arsenic, total recoverable, ug/L

Arsenic, dissolved, ug/L

Cadmium, total recoverable, ug/L

Cadmium, dissolved, ug/L

Copper, total recoverable, ug/L

Copper, dissolved, ug/L

Iron, total recoverable, ug/L

Iron, dissolved, ug/L

Lead, total recoverable, ug/L

Lead, dissolved, ug/L

Manganese, total recoverable, ug/L

Manganese, dissolved, ug/L

Zinc, total recoverable, ug/L

Zinc, dissolved, ug/L

Number of 

samples

7

7

8

7

7

7

7

7

7

6

7

7

6

7

Mean spike 

recovery, 

in percent

106.9

97.3

97.9

101.3

98.4

96.6

98.2

99.3

99.3

103.0

98.1

100.4

106.0

97.5

95-percent 

confidence 

interval for 

spike recovery, 

in percent

101-113

90.4-104

94.4-101

97.5-105

91.1-106

93.3-99.8

94.8-102

90.6-108

95.6-103

101-105

95.4-101

95.4-105

95.4-117

92.4-102

Within limits 

of dataquality 

objective

Yes

Yes

Yes

Yes

Yes

Yes

Yes

Yes

Yes

Yes

Yes

Yes

Yes

Yes

62 Water-Quality, Bed-Sediment, and Biological Data (October 1993 through September 1994) and Statistical Summaries of Data for 

Streams in the Upper Clark Fork Basin, Montana.
Table 16. Chemical analyses of field blanks for water samples

[Abbreviations: °C, degrees Celsius; |4g/L, micrograms per liter; j^S/cm, microsiemens per centimeter at 25 °C; 

mg/L, milligrams per liter. Symbols: <, less than minimum reporting level; --, no data]

Date

Oct 1993

27...

Dec 1993

15...

Febl994

17...

Mar 1994

9...

Apr 1994

12...

25...

May 1994

24...

Junl994

14...

M1994

12...

Aug 1994

18...

Specific 

conductTime ance, 

onsfte 

(nS/cm)

1000 1

1200 1

1500 2

1110 1

0845 2

1730 1

1130 1

1245 1

1115 1

1350 2

PH, 

onsfte 

(standard 

units)

5.5

--

5.7

5.4

5.4

5.5

5.4

5.7

5.6

5.8

MagneCalcium, Sodium, Potassium, Alkalinity 

sium, 

dissolved dissolved dissolved (mg/L as 

dissolved 

(mg/L) (mg/L) (mg/L) CaCO3) 

(mg/L)

0.02 <0.01

<.02 <.01

<.02 <.01 <0.2 <0.1 1.4

<.02 <.01 <.2 <-l 1.2

<.02 <.01 <.2 <-l 3.5

.03 <.01 <.2 <.l <1-0

.03 <.01 <.2 <.l 1.2

<.02 <.01 <.2 <.l 1.2

<.02 <.01 <.2 <.l 1.1

<02 <.01 <.2 <-l 1.6

Sulfate, 

dissolved 

(mg/L)

--

--

<0.1

<.l

<.l

<.l

<.l

<.l

<.l

<.l

TABLE 16 63
Table 16. Chemical analyses of field blanks for water samples (Continued)

Date

Chloride,

dissolved

(mg/L)

Fluoride,

dissolved

(mg/L)

Silica, 

dissolved

Arsenic, 

total 

recoverable

Arsenic,

dissolved

(n9/L)

Cadmium,

total 

recoverable

Cadmium, 

dissolved

Copper,

total 

recoverable

Copper, 

dissolved

Octl993

27... 

Dec 1993

15... 

Febl994

17... 

Mar 1994

9... 

Apr 1994

12...

25... 

May 1994

24... 

Junl994

14... 

M1994

12... 

Aug 1994

18... <1

64 Water-Quality, Bed-Sediment, and Biological Data (October 1993 through September 1994) and Statistical Summaries of Data for 

Streams In the Upper Clark Fork Basin, Montana.
Table 16. Chemical analyses of field blanks for water samples (Continued)

Iron, 

Iron, 

total 

Date dissolved 

recoverable

(ug/L)

(ug/L)

Oct 1993

27... - <3

Dec 1993

15... -- <3

Febl994

17... <10 <3

Mar 1994

9... <10 <3

Apr 1994

12... 20 <3

25... <10 <3

May 1994

24... <10 <3

Junl994

14... 10 <3

Jull994

12... <10 <3

Aug 1994

18... <10 <3

MangaLead, Zinc, 

Lead, nese, Manganese, Zinc, 

total total 

dissolved total dissolved dissolved 

recoverable recoverable 

(ng/L) recoverable (n9/L) (n9/L)

(ng/L)

<0.5 <1 - <3

<.5 -- <1 <3

<1 <.5 <10 <1 <10 <3

<1 <.5 <10 <1 <10 4

<1 <.5 <10 <1 <10 <3

<1 <5 <10 <1 <10 <3

<1 <5 <10 <1 <10 <3

<1 <.5 <10 <1 <10 <3

<1 <5 <10 <1 <10 <3

<1 <5 <10 <1 <10 <3

TABLE 16 65
Table 17. Trace-element analyses of fine-grained bed sediment, upper Clark Fork basin, Montana, August 1994

[Fine-grained sediment is material less than 0.064 millimeter in diameter. Concentrations are the mean of all analyses for duplicate aliquots from each 

composite sample. Abbreviation: jug/g, micrograms per gram of dry sample weight. Symbol: <, less than]

Station

number

(fig. D

12323600

12323750

12323800

12324200

12324590

12324680

12331500

12331800

12334510

12334550

12340000

12353000

Number

of cornStation name 

posite

CadmiumChromium samples

Silver Bow Creek at Opportunity

Silver Bow Creek at Warm Springs

Clark Fork near Galen

Clark Fork at Deer Lodge

Little Blackfoot River near Garrison

Clark Fork at Goldcreek

Flint Creek near Drummond

Clark Fork near Drummond

Rock Creek near Clinton

Clark Fork at Turah Bridge, near Bonner

Blackfoot River near Bonner

Clark Fork below Missoula1

3

3

3

3

3

3

3

3

3

3

3

3

38.2

10.6

11.9

6.3

<1.2

5.4

3.2

4.8

<1.2

3.6

<1.2

1.7

27.6

16.7

23.3

28.4

22.1

31.9

24.3

17.0

16.5

15.3

15.1

21.5

Copper

5,020

716

1,230

882

85

653

55

469

12

300

21

138

Concentration, in pglg

Iron

39,700

26,000

27,700

22,600

16,100

23,700

23,600

19,000

15,000

15,400

14,900

18,600

Lead

752

74

116

121

37

93

151

93

7

63

10

38

Manganese

3,200

8,590

15,600

4,480

907

2,610

5,510

2,360

278

699

497

1,340

Nickel

16.0

15.8

21.8

15.3

13.6

15.0

12.5

14.0

10.8

12.0

11.7

13.3

Silver

14.4

.3

2.8

2.4

<.7

2.3

5.0

2.4

<.7

1.3

<7

.4

Zinc

8,680

2,220

2,330

1,260

170

1,120

610

1,030

48

842

64

409

'Samples collected about 30 miles downstream of water-quality station to conform to previous sampling location.

66 Water-Quality, Bed-Sediment, and Biological Data (October 1993 through September 1994) and Statistical Summaries of Data for 

Streams in the Upper Clark Fork Basin, Montana
Table 18. Trace-element analyses of bulk bed sediment, upper Clark Fork basin, Montana, August 1994

[Bulk bed sediment collected in this study generally is material smaller than about 10 millimeters in diameter. Concentrations are the mean of all analyses for 

triplicate aliquots for each composite sample. Abbreviation: )og/g, micrograms per gram of dry sample weight. Symbol: <, less than]

Station

number

(fig-D

12323600

12323800

12324200

12324590

12324680

12331500

12331800

12334510

12334550

12340000

12353000

Station name

Silver Bow Creek at Opportunity

Clark Fork near Galen

Clark Fork at Deer Lodge

Little Blackfoot River near Garrison

Clark Fork at Goldcreek

Flint Creek near Drummond

Clark Fork near Drummond

Rock Creek near Clinton

Clark Fork at Turah Bridge, near Bonner

Blackfoot River near Bonner

Clark Fork below Missoula 1

Number

of composite

samples

1

I

1

1

1

1

1

1

1

1

1

Concentration, in pg/g

Cadmium

12.7

6.0

2.0

<1.2

2.3

1.7

1.5

<1.2

1.8

<1.2

<1.2

Chromium

14.9

18.4

13.3

14.7

17.6

10.3

13.8

10.8

15.5

17.7

4.4

Copper

1,550

685

281

19

282

25

173

7

182

19

22

iron

27,200

25,900

13,200

15,600

15,500

13,400

14,100

9,840

13,200

16,600

6,160

Lead

300

87

45

12

46

79

35

5

37

10

8

Manganese

1,670

5,410

2,060

420

1,190

3,200

711

195

414

305

223

Nickel

8.9

12.5

7.7

8.6

9.1

6.0

9.0

6.2

8.8

9.8

3.5

Silver

4.8

1.6

<.7

<.7

<.7

3.3

.7

<.7

<7

<7

<7

Zinc

3,420

1,280

456

73

549

284

434

29

510

58

88

'Samples collected about 30 miles downstream of water-quality station to conform to previous sampling location.

TABLE 18 67
Table 19. Recovery efficiency for trace-element analyses of standard reference materials for bed sediment

[Abbreviations: |ug/g, micrograms per gram of dry sample weight; SRM, standard reference material. Symbol: --, recovery could not be determined because 

all analyses were less than the analytical detection limit of 0.8 jug/g for cadmium and 0.5 jug/g for silver]

Constituent

Cadmium

Chromium

Copper

Iron

Lead

Manganese

Nickel

Silver

Zinc

Cadmium

Chromium

Copper

Iron

Lead

Manganese

Nickel

Silver

Zinc

Number of 

measurements

7

7

7

7

7

7

7

7

7

8

8

8

g

8

8

8

8

8

Dilution ratio

1:5

1:5

1:5

1:5

1:1

1:5

1:5

1:5

1:5

1:10

1:10

1:10

1:10

1:5

1:10

1:10

1:10

1:10

Certified 

concentration

(H9/9)

SRM sample 2709

0.38

130

35

35,000

19

538

88

.41

106

SRM sample 2711

41.7

47.0

114

28,900

1,160

638

20.6

4.63

350.4

Mean SRM 

recovery (percent)

-

72.2

83.3

94.0

58.7

99.5

94.3

-

98.7

106

58.8

98.1

81.9

100

86.0

88.4

67.7

103

95-percent confidence 

interval for SRM 

recovery 

(percent)

-

67.4-77.0

78.8-87.8

92.0-96.0

57.1-60.3

96.8-102

93.1-95.5

~

95.8-102

105-107

50.2-67.4

96.7-99.5

77.7-86.1

99.1-101

84.6-87.4

84.1-92.7

63.0-73.0

101-105

68 Water-Quality, Bed-Sediment, and Biological Data (October 1993 through September 1994) and Statistical Summaries of Data for 

Streams in the Upper Clark Fork Basin, Montana.
Table 20. Trace-element analyses of procedural blanks for bed sediment

[Abbreviation: ng/mL, micrograms per milliliter. Dilution ratio is the proportion of initial volume of concentrated nitric acid digestion aliquot to final volume 

of solution after addition of 0.6 N hydrochloric acid. Symbols: <, less than; --, no data]

Sample 

identification

A 

A

B 

B

C 

C

D 

D

E 

E

F 

F

G 

G

Dilution 

ratio

1:5 

1:10

1:5 

1:10

1:5 

1:10

1:5 

1:10

1:5 

1:10

1:5 

1:10

1:5 

1:10

Trace-element concentration, in ng/ml_

Cadmium

<0.007 

<.007

<.007 

<.076

<.007 

<.007

<.007 

<.007

<.007 

<.007

<.007 

<.007

<.007 

<.007

Chromium

<0.009 

<.009

<.009 

<.009

<.009 

<.009

<.009 

<.009

<.009 

<.009

<.009 

<.009

<.009 

<.009

Copper

<0.020 

<.020

<.020 

<.020

<.020 

<.020

<.020 

<.020

<.020 

<.020

<.020 

<.020

<.020 

<.020

MangaIron Lead 

nese

<0.161 <0.01 <0.007 

<.161 -- <.007

<.161 <.01 <.007 

<.161 - <.007

<.161 <.01 <.007 

<.161 -- <.007

<.161 <01 <.007 

<.161 -- <.007

<.161 <01 <.007 

<.161 -- <.007

<.161 <01 <.007 

<.161 -- <007

<.161 .02 <.007 

<.161 -- <007

Nickel

<0.019 

<.019

<.019 

<.019

<.019 

<.019

<.019 

<019

<.019 

<.019

<.019 

<.019

<.019 

<.019

Silver

<0.004 

<.004

<.004 

<004

<.004 

<.004

<.004 

<.004

<.004 

<.004

<.004 

<.004

<.004 

<.004

Zinc

<0.039 

<.039

<.039 

<.039

<.039 

<.039

<.039 

<.039

<.039 

<.039

<.039 

<.039

<.039 

<.039

TABLE 20 69
Table 21. Trace-element analyses of aquatic insects, upper Clark Fork basin, Montana, 

August 1994

[Analyses are of whole-body tissue. Composite samples made by combining similar-sized insects into a sample of 

sufficient mass for analysis. Concentrations for insect samples composed of two or more composite samples are the 

means of all analyses. Abbreviations: |ug/g, micrograms per gram of dry sample weight Symbol: <, less than 

minimum reporting level]

Taxon

Number 

of composite 

samples

Concentration, In i^g/g

Cadmium

ChromiumCopper

Iron Lead

Manganese

Nickel Zinc

12323600 Silver Bow Creek at OoDnrtnnltv

Hydropsyche morosa group

Hydropsyche tana

2

3

4.6

7.1

1.5

1.4

295

311

893

1,060

19.8

19.1

655

815

1.8

1.6

831

1,040

12323750 Silver Bow Creek at Warm Snrlnes

Hydropsyche cockerelli

Hydropsyche occidentalis

2

2

1.5

1.0

.8

.8

51.9

43.0

1,120

1,020

1.4

<3.0

2,380

2,200

1.7

1.2

211

202

1232380H Clark Fork near r.alcn

Hydropsyche cockerelli

Hydropsyche occidentalis

3

4

1.7

1.4

12324200

Hydropsyche cockerelli

Hydropsyche occidentalis

3

3

1.4

1.4

1.2

1.3

100

74

1,160

1,070

4.0

5.2

2,660

3,020

1.8

1.8

223

210

Clark Fork at Deer Lodge

1.8

2.2

113

117

1,810

1,380

14.1

10.8

966

1,760

1.7

1.9

261

245

12324590 Little Blackfnot River near Garrison

Hydropsyche cockerelli

Hydropsyche occidentalis

Arctopsyche grandis

Claassenia sabulosa

1

1

7

3

.6

<.7

.2

.2

12324680

Hydropsyche morosa group

Hydropsyche occidentalis

Arctopsyche grandis

Claassenia sabulosa

3

1

2

2

1.3

1.1

1.5

1.0

1.6

1.3

.7

.8

28.4

15.1

11.0

25.8

478

426

221

117

3.6

<3.7

.7

.4

399

434

471

53.4

1.2

.8

.5

.6

123

110

139

197

Clark Fork at Goldcreek

1.4

1.7

1.0

.8

66.1

55.5

31.8

54.6

1,180

1,190

474

204

3.8

5.4

2.9

1.1

893

1,350

1,070

137

1.2

1.0

.6

.5

177

188

185

258

12331500 Flint Creek near Dmmmnnd

Hydropsyche cockerelli

Hydropsyche occidentalis

Arctopsyche grandis

2

1

7

.4

<9

.3

1.1

1.6

1.5

17.8

15.1

13.0

1,180

1,690

953

4.4

7.5

6.3

992

1,400

2,160

1.8

3.5

1.1

126

155

170

12331800 Clark Fork near Drnmmnnd

Hydropsyche morosa group

Hydropsyche occidentalis

Arctopsyche grandis

Claassenia sabulosa

6

3

3

4

1.2

1.3

.9

.6

2.3

2.7

1.0

.8

55.2

56.8

22.2

45.2

1,570

1,720

548

149

8.9

12.2

3.9

1.1

1,610

2,820

1,350

119

1.5

1.9

.7

.4

239

278

194

295

70 Water-Quality, Bed-Sediment, and Biological Data (October 1993 through September 1994) and Statistical Summaries of Data for 

Streams In the Upper Clark Fork Basin, Montana.
Table 21. Trace-element analyses of aquatic insects, upper Clark Fork basin, Montana, 

August 1994 (Continued)

Taxon

Number 

of composite 

samples

Concentration, In yg/g

Cadmium

Chromium

Copper

Iron Lead

Manganese

Nickel Zinc

12334S10 Rock Creek near Clinton

Hydropsyche cockerelli

Hydropsyche occidentalis

Arctopsyche grandis

Claassenia sabulosa

2

1

6

2

 c.2

<6

.1

.1

.9

2.4

.9

.6

6.3

10.2

6.8

29.6

491

648

429

83.9

<1.1

<3.0

<.7

<5

200

268

202

38.1

.4

1.7

.5

.2

84

122

109

229

12334550 Clark Fork at Turah Bridee. near Bonner

Hydropsyche cockerelli

Hydropsyche occidentalis

Arctopsyche grandis

Claassenia sabulosa

5

1

5

2

.7

.6

.7

.5

1.6

1.5

1.2

.6

38.9

34.9

25.5

49.1

1,040

974

679

94.0

2.6

3.0

2.6

<5

535

646

561

60.7

1.1

1.0

.8

.3

178

179

176

222

12353000 Clark Fork below Mlssoula1

Hydropsyche cockerelli

Hydropsyche occidentalis

Arctopsyche grandis

Claassenia sabulosa

Chematopsyche sp.

3

1

2

4

1

.6

.9

.5

.3

1.0

1.9

2.3

1.0

.6

3.1

28.8

30.1

16.9

49.5

31.6

1,330

1,420

454

72.0

2,490

1.4

2.4

1.2

<.5

<3.3

1,160

1,460

1,060

116

1,390

1.4

2.2

.8

.2

2.9

165

193

147

237

144

'Samples collected about 30 miles downstream of water-quality station to conform to previous sampling location.

TABLE 21 71
Table 22. Recovery efficiency for trace-element analyses of standard reference material for biota

[Abbreviations: SRM, standard reference material; (ag/g, micrograms per gram of dry sample weight]

95-percent confidence

Number of Certified concentration (Mean SRM recovery Interval for SRM 

Constituent

measurements (v9/9) (percent) recovery

(percent) 

SRM sample J566J

Cadmium 7 4.15 102 102-103 

Chromium 7 1.43 105 97.5-112

Copper 7 66.3 101 98.9-103

Iron 7 539 93.8 92.2-95.4

Lead 7 .37 79.1 63.0-95.2

Manganese 7 12.3 94.9 92.7-97.1

Nickel 7 2.25 111 88.1-134

Zinc 7 830 95.1 93.7-96.5

72 Water-Quality, Bed-Sediment, and Biological Data (October 1993 through September 1994) and Statistical Summaries of Data for 

Streams in the Upper Clark Fork Basin, Montana.
Table 23. Trace-element analyses of procedural blanks for biota

[Abbreviation: fig/mL, micrograms per milliliter. Blanks were not diluted prior to analysis. Symbol: <, less than]

Trace-element concentration,

ww»ii|riw

identification

A

B

C

D

E

F

G

H

I

J

VIIMMWI I

ratio

1:1

1:1

1:1

1:1

1:1

1:1

1:1

1:1

1:1

1:1

Cadmium

<0.004

<.004

<.004

<.004

<.004

<.004

<.004

<.004

<.004

<.004

Chromium

0.007

.005

.029

.013

.017

.015

.016

.012

.017

.014

Copper

<0.002

<.002

<.002

<.002

<.002

<.002

<.002

<.002

<.002

<.002

Iron Lead

<0.03 <0.01

<.03 <.01

<.03 <.01

<.03 <.01

.03 <.01

<.03 <.01

<.03 <.01

<.03 <.01

.13 <.01

.06 <.01

Manganese

0.006

<.002

.004

.010

<.002

<.002

.030

<.002

<.002

<.002

Nickel

<0.005

<.005

.011

.006

<.005

<.005

<.005

<.005

<.005

<.005

Zinc

<0.002

<.002

<.002

<.002

.25

.021

<.002

<.002

<.002

.010

TABLE 23 73
Table 24. Statistical summary of water-quality data for the upper Clark Fork basin, Montana, March 1985 

through September 1994

[Abbreviations: ftVs, cubic feet per second; °C, degrees Celsius; ug/L, micrograms per liter; uS/cm, microsiemens per centimeter at 25 °C; mg/L, 

milligrams per liter; mm, millimeter; ton/d, tons per day. Symbols: <, less than minimum reporting level 1 ; ~, indicates insufficient data 

greater than minimum reporting level to compute statistic]

Property or constituent and reporting unit

Number of 

samples

Maximum

Minimum Mean Median

12323230-BLACKTAIL CREEK AT HARRISON AVENUE. AT BUTTE. MONT.

Period of record for water-quality data: March 1993-September 1994

Streamflow, instantaneous (ftVs)

Specific conductance, onsite (uS/cm)

Temperature, water (°C)

pH, onsite (standard units)

Hardness, total (mg/L as CaCO3)

Calcium, dissolved (mg/L)

Magnesium, dissolved (mg/L)

Sodium, dissolved (mg/L)

Potassium, dissolved (mg/L)

Alkalinity (mg/L as CaCO3)

Sulfate, dissolved (mg/L)

Chloride, dissolved (mg/L)

Fluoride, dissolved (mg/L)

Silica, dissolved (mg/L)

Dissolved solids, calculated (mg/L)

Arsenic, total recoverable (ug/L)

Arsenic, dissolved (ug/L)

Cadmium, total recoverable (ug/L)

Cadmium, dissolved (ug/L)

Copper, total recoverable (ug/L)

Copper, dissolved (ug/L)

lion, total recoverable (ug/L)

lion, dissolved (ug/L)

Lead, total recoverable (ug/L)

Lead, dissolved (ug/L)

Manganese, total recoverable (ug/L)

Manganese, dissolved (ug/L)

Zinc, total recoverable (ug/L)

Zinc, dissolved (ug/L)

Sediment, suspended concentration (mg/L)

Sediment, suspended discharge (ton/d)

Sediment, suspended (percent finer than 0.062 mm)

18

18

18

18

18

18

18

18

18

18

18

18

18

18

18

18

18

18

18

18

18

18

18

18

18

18

18

18

18

18

18

18

30

340

17.0

8.2

140

39

9.7

16

4.2

117

36

8.9

.6

32

208

10

8

<1

.1

52

9

3,800

360

47

1

190

99

130

11

123

3

95

3.1

184

2.5

7.6

71

20

5.0

7.2

2.0

62

18

3.6

.2

14

116

2

2

<1

<.l

2

<1

260

24

<1

<.5

30

17

<10

<3

3

.05

61

9.5

258

8.7

7.8

103

30

7.1

10

2.6

89

26

6.0

.3

25

160

6

4

--

-

10

24

832

161

26

-

69

42

220

25

19

.55

86

7.7

258

8.8

7.7

105

30

7.2

11

2.5

89

28

5.6

.3

24

162

6

4

<1

<1

7

4

570

165

1

<5

60

40

10

5

7

.12

88

74 Water-Quality, Bed-Sediment, and Biological Data (October 1993 through September 1994) and Statistical Summaries of Data for 

Streams in the Upper Clark Fork Basin, Montana.
Table 24. Statistical summary of water-quality data for the upper Clark Fork basin, Montana, March 1985 

through September 1994 (Continued)

Property or constituent and reporting unit

Number of 

samples

Maximum Minimum Mean Median

12323250-SILVER BOW CREEK BELOW BLACKTAIL CREEK. AT BUTTE. MONT.

Period of record for water-quality data

Streamflow, instantaneous (fP/s)

Specific conductance, onsite (uS/cm)

Temperature, water (°C)

pH, onsite (standard units)

Hardness, total (mg/L as CaCO3)

Calcium, dissolved (mg/L)

Magnesium, dissolved (mg/L)

Sodium, dissolved (mg/L)

Potassium, dissolved (mg/L)

Alkalinity (mg/L as CaCO3)

Sulfate, dissolved (mg/L)

Chloride, dissolved (mg/L)

Fluoride, dissolved (mg/L)

Silica, dissolved (mg/L)

Dissolved solids, calculated (mg/L)

Arsenic, total recoverable (ug/L)

Arsenic, dissolved (ug/L)

Cadmium, total recoverable (ug/L)

Cadmium, dissolved (ug/L)

Copper, total recoverable (ug/L)

Copper, dissolved (ng/L)

Iron, total recoverable (ug/L)

Iron, dissolved (ng/L)

Lead, total recoverable (\igfL) 

Lead, dissolved (ng/L)

Manganese, total recoverable (ug/L)

Manganese, dissolved (ug/L)

Zinc, total recoverable (|ig/L)

Zinc, dissolved (ug/L)

Sediment, suspended concentration (mg/L)

Sediment, suspended discharge (ton/d)

Sediment, suspended (percent finer than 0.062 mm)

18

18

18

18

18

18

18

18

18

17

17

17

17

17

17

18

18

18

18

18

18

18

18

18 

18

18

18

18

18

18

18

18

: March

52

631

16.0

7.8

170

48

12

34

35

133

96

28

.8

28

353

39

10

6

6.2

550

120

7,400

220

250 

2.4

1,600

1,700

2,200

2,200

162

16

93

1993 -September 1994

15

315

1.5

7.3

100

30

7.1

16

4.0

65

46

13

.3

17

177

10

5

2

1.3

85

47

310 1

26

3 

<.5

540

490

550

460

3

.14

71

27

470

10.5

7.5

144

42

10

24

9.9

89

75

20

.5

23

259

16

8

3

2.2

199

80

,530

93

34 

2 .9

825

754

972

794

29

2.5

88

25

466

9.0

7.5

145

42

10

24

5.7

89

76

20

.5

23

255

15

8

2

2.1

145

78

810

86

12 

.8

705

690

920

765

16

.90

88

TABLE 24 75
Table 24. Statistical summary of water-quality data for the upper Clark Fork basin, Montana, March 1985 

through September 1994 (Continued)

Property or constituent and reporting unit

Number of 

samples

Maximum Minimum Mean Median

1232360Q-SILVER BOW CREEK AT OPPORTUNITY. MONT. 

Period of record for water-quality data: March 1993-September 1994

Streamflow, instantaneous (fiP/s) 

Specific conductance, onsite (uS/cm) 

Temperature, water (°C) 

pH, onsite (standard units) 

Hardness, total (mg/L as CaCC^) 

Calcium, dissolved (mg/L) 

Magnesium, dissolved (mg/L) 

Sodium, dissolved (mg/L) 

Potassium, dissolved (mg/L) 

Alkalinity (mg/L as CaCO3) 

Sulfate, dissolved (mg/L) 

Chloride, dissolved (mg/L) 

Fluoride, dissolved (mg/L) 

Silica, dissolved (mg/L) 

Dissolved solids, calculated (mg/L) 

Arsenic, total recoverable (ug/L) 

Arsenic, dissolved (ug/L) 

Cadmium, total recoverable (ug/L) 

Cadmium, dissolved (ug/L) 

Copper, total recoverable (ug/L) 

Copper, dissolved (ug/L) 

Iron, total recoverable (ug/L) 

Iron, dissolved (ug/L) 

Lead, total recoverable (ug/L) 

Lead, dissolved (ug/L) 

Manganese, total recoverable (ug/L) 

Manganese, dissolved (ng/L) 

Zinc, total recoverable (ug/L) 

Zinc, dissolved (ug/L)

Sediment, suspended concentration (mg/L)

Sediment, suspended discharge (ton/d)

Sediment, suspended (percent finer than 0.062 mm)

20

19

19

19

19

19

19

19

19

18

18

18

18

18

18

19

19

19

19

19

19

19

19

19

19

19

19

19

19

20

20

20

143

593

17.0

8.9

200

54

15

26

16

117

190

19

.8

28

374

170

34

49

41

3,900

450

8,600

150

260

2.3

10,000

9,300

15,000

13,000

384

52

92

26

270

0.0

7.2

98

30

5.7

10

2.9

60

38

6.4

.2

15

161

11

1

.5

79

28

290

<3

7

330

270

230

110

6

.42

60

69

373

9.5

8.3

131

39

8.4

17

5.5

89

70

11

.4

21

229

32

10

24

3.3

387

86

1,650

252

39

2 .6

1,090

985

1,260

951

53

9.2

76

54

370

10.0

8.3

130

40

8.4 

16 

4.2 

89 

63 

11

.4

21

228

16

8

2

1.1 

140 

57 

830 

44 

13 

<.5 

600 

510 

470 

220 

13 

2.0 

79

76 Water-Quality, Bed-Sediment, and Biological Data (October 1993 through September 1994) and Statistical Summaries of Data for 

Streams in the Upper Clark Fork Basin, Montana.
Table 24. Statistical summary of water-quality data for the upper Clark Fork basin, Montana, March 1985 

through September 1994 (Continued)

Property or constituent and reporting unit

Number of 

samples

Maximum Minimum Mean Median

12323750-SILVER BOW CREEK AT WARM SPRINGS. MONT.

Period of record for water-quality data:

Streamflow, instantaneous (ft3/s)

Specific conductance, onsite (uS/cm)

Temperature, water (°C)

pH, onsite (standard units)

Hardness, total (mg/L as CaCO3)

Calcium, dissolved (mg/L)

Magnesium, dissolved (mg/L)

Sodium, dissolved (mg/L)

Potassium, dissolved (mg/L)

Alkalinity (mg/L as CaCO3)

Sulfate, dissolved (mg/L)

Chloride, dissolved (mg/L)

Fluoride, dissolved (mg/L)

Silica, dissolved (mg/L)

Dissolved solids, calculated (mg/L)

Arsenic, total recoverable (ug/L)

Arsenic, dissolved (ug/L)

Cadmium, total recoverable (ug/L)

Cadmium, dissolved (ug/L)

Copper, total recoverable (ug/L)

Copper, dissolved (ug/L)

Iron, total recoverable (ug/L)

Iron, dissolved (ug/L) 

Lead, total recoverable (ug/L)

Lead, dissolved (ug/L)

Manganese, total recoverable (ug/L)

Manganese, dissolved (ug/L)

Zinc, total recoverable (ug/L) 

Zinc, dissolved (ug/L)

Sediment, suspended concentration (mg/L)

Sediment, suspended discharge (ton/d)

Sediment, suspended (percent finer than 0.062 mm)

20

18

19

18

18

18

18

18

18

18

18

18

18

18

18

18

18

18

18

18

18

18

18 

18

18

18

18

18 

18

20

20

19

March 1993 -September 1994

347

614

22.0

9.3

260

78

19

23

5.6

120

210

15

1.2

20

396

29

27

<1

.2

60

32

660

27 

5

<.5

570

500

180

73

22

12

97

24

361

2.0

8.0

150

44

9.1

11

3.4

69

75

1.3

.5

7.6

227

12

10

<1

<.l

10

8

130

3

<.5

80

34

20 

<3

2

.26

67

133

469

13.0

8.8

198

58

13

16

4.4

95

127

7.7

.8

13

297

20

18

-

2.1

29

15

349

12

22

-

254

164

81

2 17

8

3.4

82

91

475

15.0

8.8

190

56

12

16

4.3

96

135

7.2

.7

12

298

20

18

<1

.1

24

14

320

11 

1

<.5

220

135

70 

11

7

1.8

82

TABLE 24 77
Table 24. Statistical summary of water-quality data for the upper Clark Fork basin, Montana, March 1985 

through September 1994 (Continued)

Property or constituent and reporting unit

Number of 

samples

Maximum Minimum Mean Median

12323770-WARM SPRINGS CREEK AT WARM SPRINGS. MONT.

Period of record for water quality data: March 1993-September 1994

Streamflow, instantaneous (ft3/s)

Specific conductance, onsite (uS/cm)

Temperature, water (°C)

pH, onsite (standard units)

Hardness, total (mg/L as CaCC^)

Calcium, dissolved (mg/L)

Magnesium, dissolved (mg/L)

Sodium, dissolved (mg/L)

Potassium, dissolved (mg/L)

Alkalinity (mg/L as CaCO3)

Sulfate, dissolved (mg/L)

Chloride, dissolved (mg/L)

Fluoride, dissolved (mg/L)

Silica, dissolved (mg/L)

Dissolved solids, calculated (mg/L)

Arsenic, total recoverable (ug/L)

Arsenic, dissolved (ug/L)

Cadmium, total recoverable (ug/L)

Cadmium, dissolved (ug/L)

Copper, total recoverable (ug/L)

Copper, dissolved (ug/L)

Iron, total recoverable (ug/L)

Iron, dissolved (ug/L) 

Lead, total recoverable (ug/L)

Lead, dissolved (ug/L)

Manganese, total recoverable (ug/L)

Manganese, dissolved (ug/L) 

Zinc, total recoverable (ug/L) 

Zinc, dissolved (ug/L)

Sediment, suspended concentration (mg/L)

Sediment, suspended discharge (ton/d)

Sediment, suspended (percent finer than 0.062 mm)

12

11

12

11

11

11

11

11

11

11

11

11

11

11

11

11

11

11

11

11

11

11

11 

11

11

11

11 

11 

11

12

12

12

206

795

16.0

8.6

420

130

22

7.4

4.7

146

270

3.2

.6

13

536

16

14

<1

<.l

75

16

1,400

30 

9

1.8

1,400

570 

60 

10

90

49

88

2.8

180

.5

7.8

83

26

4.4

1.8

.9

68

20

.5

.3

8.7

103

4

3

<1

<.l

4

2

40

5 

<1

<.5

120

74 

<10 

<3

4

.14

57

96

349

8.7

8.2

172

53

9.8

3.6

1.7

105

72

1.2

.4

11

215

8

5

--

--

24

4

395

13 

23

--

385

171 

2 17 

24

24

8.5

75

92

262

9.2

8.2

130

39

7.3

2.7

1.3

98

37

1.0

.4

10

155

6

4

<1

<.l

10

3

160

12 

<1

<.5

200

110 

10 

3

12

2.0

76

78 Water-Quality, Bed-Sediment, and Biological Data (October 1993 through September 1994) and Statistical Summaries of Data for 

Streams in the Upper Clark Fork Basin, Montana.
Table 24. Statistical summary of water-quality data for the upper Clark Fork basin, Montana, March 1985 

through September 1994 (Continued)

Property or constituent and reporting unit

Number of 

samples

Maximum Minimum Mean Median

12323800-CLARK FORK NEAR GAT.ENr MONT. 

Period of record for water-quality data: July 1988-September 1994

Streamflow, instantaneous (frVs) 

Specific conductance, onsite (uS/cm) 

Temperature, water (°C) 

pH, onsite (standard units) 

Hardness, total (mg/L as CaCO3) 

Calcium, dissolved (mg/L) 

Magnesium, dissolved (mg/L) 

Sodium, dissolved (mg/L) 

Potassium, dissolved (mg/L) 

Alkalinity (mg/L as CaCO3) 

Sulfate, dissolved (mg/L) 

Chloride, dissolved (mg/L) 

Fluoride, dissolved (mg/L) 

Silica, dissolved (mg/L) 

Dissolved solids, calculated (mg/L) 

Arsenic, total recoverable (ug/L) 

Arsenic, dissolved (ug/L) 

Cadmium, total recoverable (ug/L) 

Cadmium, dissolved (ug/L) 

Copper, total recoverable (ug/L) 

Copper, dissolved (ug/L) 

Iron, total recoverable (ug/L) 

Iron, dissolved (ug/L) 

Lead, total recoverable (ug/L) 

Lead, dissolved (ug/L) 

Manganese, total recoverable (ug/L) 

Manganese, dissolved (ug/L) 

Zinc, total recoverable (ug/L) 

Zinc, dissolved (ug/L)

Sediment, suspended concentration (mg/L)

Sediment, suspended discharge (ton/d)

Sediment, suspended (percent finer than 0.062 mm)

60 

48 

59 

47 

46 

46 

46 

18 

18 

18 

18 

IS 

18 

18 

18 

46 

46 

46 

46

45

46

46

46

46

46

46

46

46

46

60

60

59

626

720

22.5

8.9

370

110

22

18

5.3

130

220

11

1.1

17

428

60

30

3

1

240

50

9,200

110

28

3

1,400

360

360

110

338

338

97

14

220

.0

7.5

96

29

5.7

7.5

2.2

82

56

3.2

.5

8.7

179

3

4

10 

3

90 

<3

80 

33 

10 

<3

2

.12

64

167

463

9.7

8.4

206

61

13

12

3.5

101

106

6.3

.6

12

268

17

12

2.4

2.1

41

12

708

18

25

2 .5

342

139

73

21

21

18

80

97

474

10.0

8.4

205

61

14

12

3.3

98

98

6.2

.6

12

267

15

12

29

10

320

10

2

<1

285

115

55

13

8

2.2 

80

TABLE 24 79
Table 24. Statistical summary of water-quality data for the upper Clark Fork basin, Montana, March 1985 

through September 1994 (Continued)

Property or constituent and reporting unit

12324200-CL

Number of 

samples

Maximum Minimum Mean Median

ARK FORK AT DEER LODGE. MONT.

Period of record for water-quality data: March 1985-September 1994

Streamflow, instantaneous (ft3/s) 113 1,920 23

Specific conductance, onsite (nS/cm)

Temperature, water (°C)

pH, onsite (standard units)

Hardness, total (mg/L as CaCO3)

Calcium, dissolved (mg/L)

Magnesium, dissolved (mg/L)

Sodium, dissolved (mg/L)

Potassium, dissolved (mg/L)

Alkalinity (mg/L as CaCO3)

Sulfate, dissolved (mg/L)

Chloride, dissolved (mg/L)

Fluoride, dissolved (mg/L)

Silica, dissolved (mg/L)

Dissolved solids, calculated (mg/L)

Arsenic, total recoverable (ng/L)

Arsenic, dissolved (ng/L) 

Cadmium, total recoverable (ng/L)

Cadmium, dissolved (|ag/L)

Copper, total recoverable (|Jg/L)

Copper, dissolved (ng/L)

Iron, total recoverable (|ag/L) 

Iron, dissolved (|jg/L) 

Lead, total recoverable (|ig/L) 

Lead, dissolved (ng/L)

Manganese, total recoverable (ng/L)

Manganese, dissolved (|ag/L)

Zinc, total recoverable (|Jg/L)

Zinc, dissolved (fig/L)

Sediment, suspended concentration (mg/L)

Sediment, suspended discharge (ton/d)

Sediment, suspended (percent finer than 0.062 mm)

96

112

61

53

53

53

18

18

19

18

18

18

18

18

63

63 

63

63

62

63

63 

63 

63 

63

63

63

63

63

113

113

104

642

23.0

8.6

270

81

18

25

6.3

182

140

12

.7

34

374

200

39

5

2

1,500

120

29,000 

150 

200 

6

4,600

400

1,700

230

2,250

8,690

99

262

.0

7.4

120

37

7.2

10

2.6

102

66

1.2

.1

13

209

8

7 

<1

<.l

11

4

261

514

9.4

8.1

218

64

14

15

3.7

133

98

6.9

.6

18

298

25

14 

2.7

--

113

13

60 2,480 

<3 2 16 

<1 2 15 

<.5 2.8

30

1

10

3

2

.29

40

373

47

140

19

89

210

72

209

538

10.0

8.2

230

66

14

14

3.4

141

95

6.8

.6

17

306

17

12

<1

<1

50

9

730 

10

5 

<1

210

31

70

14

23

11

74

80 Water-Quality, Bed-Sediment, and Biological Data (October 1993 through September 1994) and Statistical Summaries of Data for 

Streams in the Upper Clark Fork Basin, Montana.
Table 24. Statistical summary of water-quality data for the upper Clark Fork basin, Montana, March 1985 

through September 1994 (Continued)

Property or constituent and reporting unit

12324590-LITTLE BI

Number of 

samples

Maximum Minimum Mean Median

ACKFOOT RIVER NEAR GARRISON. MONT.

Period of record for water-quality data:

Streamflow, instantaneous (ftVs)

Specific conductance, onsite (|iS/cm)

Temperature, water (°C)

pH, onsite (standard units)

Hardness, total (mg/L as CaCC^)

Calcium, dissolved (mg/L)

Magnesium, dissolved (mg/L)

Sodium, dissolved (mg/L)

Potassium, dissolved (mg/L)

Alkalinity (mg/L as CaCO3)

Sulfate, dissolved (mg/L)

Chloride, dissolved (mg/L)

Fluoride, dissolved (mg/L)

Silica, dissolved (mg/L)

Dissolved solids, calculated (mg/L)

Arsenic, total recoverable (|ig/L)

Arsenic, dissolved (|ig/L)

Cadmium, total recoverable (|ig/L)

Cadmium, dissolved (|ig/L)

Copper, total recoverable (|ig/L)

Copper, dissolved (|ig/L)

Iron, total recoverable (ng/L)

Iron, dissolved (|ig/L)

Lead, total recoverable (|ig/L)

Lead, dissolved (|ig/L)

Manganese, total recoverable (ug/L)

Manganese, dissolved (|ig/L)

Zinc, total recoverable (|ig/L)

Zinc, dissolved (|ig/L)

Sediment, suspended concentration (mg/L)

Sediment, suspended discharge (ton/d)

Sediment, suspended (percent finer than 0.062 mm)

56

44

55

43

38

38

38

12

11

11

11

11

11

12

11

43

43

43

43

42

43

43

43

43

42

43

43

43

43

56

56

56

March 1985-September 1994

2,080

300

22

8.5

140

43

9.4

7.3

4.5

141

20

3.4

.2

23

182

17

7

2

1

45

7

25,000

120

25

6

1,100

30

140

24

1,410

7,920

95

21

120

.0

7.0

51

14

3.3

3.4

1.3

52

9.8

.8

.1

17

96

4

3

<1

<.l

<1

<1

20 1,

<3

<1

<.5

<10 2

1

<10

<3

1

.08

49

297

219

7.3

7.9

101

29

6.8

5.1

2.0

95

13

1.4

.2

19

134

7

5

2.4

--

26

22

790

234

24

2.7

102

8

220

25

70

213

74

184

215

7.0

7.9

99

28

6.8

5.3

1.8

93

14

1.3

.2

19

133

6

5

<1

<1

3

2

330

23

1

<1

30

6

10

4

10

4.4

79

TABLE 24 81
Table 24. Statistical summary of water-quality data for the upper Clark Fork basin, Montana, March 1985 

through September 1994 (Continued)

Property or constituent and reporting unit

12324680-CL

Number of 

samples

Maximum Minimum Mean Median

ARK FORK AT GOLDCREEK MONT.

Period of record for water-quality data

Streamflow, instantaneous (frVs)

Specific conductance, onsite (jiS/cm)

Temperature, water (°C)

pH, onsite (standard units)

Hardness, total (mg/L as CaCO3)

Calcium, dissolved (mg/L)

Magnesium, dissolved (mg/L)

Sodium, dissolved (mg/L)

Potassium, dissolved (mg/L)

Alkalinity (mg/L as CaCO3)

Sulfate, dissolved (mg/L)

Chloride, dissolved (mg/L)

Fluoride, dissolved (mg/L)

Silica, dissolved (mg/L)

Dissolved solids, calculated (mg/L)

Arsenic, total recoverable (jig/L)

Arsenic, dissolved (ng/L)

Cadmium, total recoverable (ng/L)

Cadmium, dissolved (|Jg/L)

Copper, total recoverable (ng/L)

Copper, dissolved (jig/L)

Iron, total recoverable (ng/L)

Iron, dissolved (|ag/L)

Lead, total recoverable (ng/L)

Lead, dissolved (ng/L)

Manganese, total recoverable (ng/L)

Manganese, dissolved (|ig/L)

Zinc, total recoverable (ng/L)

Zinc, dissolved (ng/L)

Sediment, suspended concentration (mg/L)

Sediment, suspended discharge (ton/d)

Sediment, suspended (percent finer than 0.062 mm)

19

18

19

18

18

18

18

18

18

18

18

18

18

18

18

18

18

18

18

17

17

18

18

17

17

18

18

18

18

19

19

19

: March 1993-September 1994

1,410

450

20.0

8.6

200

59

13

19

6.9

172

84

7.2

.6

25

286

31

18

<1

<.l

150

20

2,700

58

18

<.5

470

35

180

22

152

392

90

87

280

.0

8.1

120

36

7.8

7.8

2.1

89

40

3.1

.3

16

170

8

6

<1

<.l

8

4

60

4

<1

<5

30

11

10

<3

4

.94

52

649

379

9.6

8.3

166

49

11

11

3.1

127

59

4.6

.4

19

234

14

10

--

40

7

802

18

25

--

141

22

56

2 10

40

89

79

529

396

11.0

8.3

175

51

11

12

2.8

131

52

4.1

.4

18

245

13

10

<l

<.l

33

6

520

13

4

<.5

115

22

45

9

22

38

81

82 Water-Quality, Bed-Sediment, and Biological Data (October 1993 through September 1994) and Statistical Summaries of Data for 

Streams In the Upper Clark Fork Basin, Montana.
Table 24. Statistical summary of water-quality data for the upper Clark Fork basin, Montana, March 1985 

through September 1994 (Continued)

Property or constituent and reporting unit

Number of 

samples

Maximum Minimum Mean Median

12331500--FLINT CREEK NEAR DRUMMOND. MONT.

Period of record for water-quality data:

Streamflow, instantaneous (fP/s) 68

Specific conductance, onsite (uS/cm)

Temperature, water (°C)

pH, onsite (standard units)

Hardness, total (mg/L as CaCO3 )

Calcium, dissolved (mg/L)

Magnesium, dissolved (mg/L)

Sodium, dissolved (mg/L)

Potassium, dissolved (mg/L)

Alkalinity (mg/L as CaCO3 )

Sulfate, dissolved (mg/L)

Chloride, dissolved (mg/L)

Fluoride, dissolved (mg/L)

Silica, dissolved (mg/L)

Dissolved solids, calculated (mg/L)

Arsenic, total recoverable (ug/L)

Arsenic, dissolved (ug/L) 

Cadmium, total recoverable (ug/L)

Cadmium, dissolved (ug/L)

Copper, total recoverable (ug/L) 

Copper, dissolved (ug/L)

Iron, total recoverable (ug/L)

Iron, dissolved (ug/L) 

Lead, total recoverable (ug/L) 

Lead, dissolved (ug/L)

Manganese, total recoverable (ug/L)

Manganese, dissolved (ug/L) 

Zinc, total recoverable (ug/L) 

Zinc, dissolved (ug/L)

Sediment, suspended concentration (mg/L)

Sediment, suspended discharge (ton/d)

Sediment, suspended (percent finer than 0.062 mm)

57

66

54

47

47

47

19

18

18

18

18

18

19

18

54

54 

54

54

53

54

54

54 

54 

54

54

54 

54 

54

68

68

68

March

892

507

21.0

8.8

260

73

20

15

7.8

237

32

6.5

.4

32

318

50

20 

3

<1

32

7

7,200

190

87

7

1,600

120 

290

27

556

904

98

1985-September 1994

4.2

135

.0

7.5

60

17

4.3

3.8

1.0

65

7.9

1.5

.1

13

94

7

5 

<1

<.l

1 

<1

70 1

4 

<1

<.5

50

15 

<10 

<3

3

.03

28

160

311

8.9

8.2

151

41

12

7.8

3.3

138

16

3.6

.2

20

184

18

9

2.3

~

8

22

,160

33 

2 13 

2 1

251

45 

249

27

55

47

81

111

307

9.5

8.3

150

39

12

7.8

2.9

143

14

3.2

.2

20

186

14

9 

<1

<1

7 

2

565

26 

8 

<5

145

40 

30

5

26

8.6

85

TABLE 24 83
Table 24. Statistical summary of water-quality data for the upper Clark Fork basin, Montana, March 1985 

through September 1994 (Continued)

Property or constituent and reporting unit

Number of 

samples

Maximum Minimum Mean Median

1233180Q-CLARK FORK NEARDRUMMOND. MONT. 

Period of record for water-quality data: March 1993-September 1994

Streamflow, instantaneous (frVs)

Specific conductance, onsite (nS/cm)

Temperature, water (°C)

pH, onsite (standard units)

Hardness, total (mg/L as CaCO3 )

Calcium, dissolved (mg/L)

Magnesium, dissolved (mg/L)

Sodium, dissolved (mg/L)

Potassium, dissolved (mg/L)

Alkalinity (mg/L as CaCO3)

Sulfate, dissolved (mg/L)

Chloride, dissolved (mg/L)

Fluoride, dissolved (mg/L)

Silica, dissolved (mg/L)

Dissolved solids, calculated (mg/L)

Arsenic, total recoverable (ng/L)

Arsenic, dissolved (ng/L)

Cadmium, total recoverable (ng/L)

Cadmium, dissolved (ug/L)

Copper, total recoverable (ng/L)

Copper, dissolved (ng/L)

Iron, total recoverable (ng/L)

Iron, dissolved (ng/L)

Lead, total recoverable (ng/L)

Lead, dissolved (ng/L)

Manganese, total recoverable (ng/L)

Manganese, dissolved (ng/L)

Zinc, total recoverable (ng/L)

Zinc, dissolved (ng/L)

Sediment, suspended concentration (mg/L)

Sediment, suspended discharge (ton/d)

Sediment, suspended (percent finer than 0.062 mm)

19

18

19

18

18

18

18

18

18

18

18

18

18

18

18

18

18

18

18

16

16

18

18

14

14

18

18

18

18

19

19

19

1,710

630

21.0

8.5

300

83

22

20

7.3

199

130

7.8

.5

24

410

30

13

1

.2

140

17

4,000

45

40

1.2

490

29

260

21

270

1,200

90

149

278

1.0

8.0

120

36

8.3

7.8

2.1

93

38

3.3

.2

17

176

8

7

5 

1

50 

<3

20

8

<3

7

7.6 

53

880

421

10.8

8.3

192

55

13

12

3.5

144

68

4.9

.4

20

263

15

10

37

6

924

2 15

156

16

268

29

56

177

75

846

436

12.0

8.3

195

56

13

12

3.4

147

65

4.6

.4

19

270

12

10

24 

5

580

10

4

<.

115

15

50

9

28

56

75

84 Water-Quality, Bed-Sediment, and Biological Data (October 1993 through September 1994) and Statistical Summaries of Data for 

Streams in the Upper Clark Fork Basin, Montana.
Table 24. Statistical summary of water-quality data for the upper Clark Fork basin, Montana, March 1985 

through September 1994 (Continued)

Property or constituent and reporting unit

Number of 

samples

Maximum Minimum Mean Median

12334510-ROCK CREEK NEAR CLINTON. MONT.

Period of record for water-quality data

Streamflow, instantaneous (frVs)

Specific conductance, onsite (uS/cm)

Temperature, water (°C)

pH, onsite (standard units)

Hardness, total (mg/L as CaCO3)

Calcium, dissolved (mg/L)

Magnesium, dissolved (mg/L)

Sodium, dissolved (mg/L)

Potassium, dissolved (mg/L)

Alkalinity (mg/L as CaCO3)

Sulfate, dissolved (mg/L)

Chloride, dissolved (mg/L)

Fluoride, dissolved (mg/L)

Silica, dissolved (mg/L)

Dissolved solids, calculated (mg/L)

Arsenic, total recoverable (ng/L)

Arsenic, dissolved (ng/L)

Cadmium, total recoverable (ug/L)

Cadmium, dissolved (ug/L)

Copper, total recoverable (ug/L)

Copper, dissolved (ng/L)

Iron, total recoverable (ng/L)

Iron, dissolved (ng/L)

Lead, total recoverable (ug/L)

Lead, dissolved (ug/L)

Manganese, total recoverable (ug/L)

Manganese, dissolved (|ig/L)

Zinc, total recoverable (ng/L)

Zinc, dissolved (ug/L)

Sediment, suspended concentration (mg/L)

Sediment, suspended discharge (ton/d)

Sediment, suspended (percent finer than 0.062 mm)

55

46

55

45

37

37

37

11

11

11

11

11

11

11

11

43

43

43

43

41

42

43

43

41

41

43

43

43

43

55

55

55

: March 1985-September 1994

3,010

155

18

8.6

90

23

8.0

3.5

1.3

75

5.2

1.0

.2

13

90

2

1

3

1

41

6

2,100

110

19

5

90

8

60

15

157

1,280

95

113

55

.0

6.9

25

6.5

2.2

1.7

.8

26

2.0

.3

<.l

10

40

<1

<1

<1

<.l

<1

<1

40

5

<1

<.5

<10

<1

<10

<3

1

.31

35

839

106

7.9

7.8

51

13

4.4

2.6

1.0

52

3.5

.6

2-l

11

67

2.9

2 1

2 .5

-

25

22

365

34

23

2.9

2 19

22

2 12

23

19

91

70

548

98

9.0

7.8

50

13

4.3

2.5

1.1

57

3.1

.6

.1

11

70

<1

<1

<1

<1

3

1

200

34

1

<1

10

1

<10

<3

6

9.8

72

TABLE 24 85
Table 24. Statistical summary of water-quality data for the upper Clark Fork basin, Montana, March 1985 

through September 1994 (Continued)

Property or constituent and reporting unit

Number of 

samples

Maximum Minimum

12334550-CLARK FORK AT TURAH BRIDGE. NEAR BONNER.

Period of record for water-quality data

Streamflow, instantaneous (ftVs)

Specific conductance, onsite (uS/cm)

Temperature, water (°C)

pH, onsite (standard units)

Hardness, total (mg/L as CaCC^)

Calcium, dissolved (mg/L)

Magnesium, dissolved (mg/L)

Sodium, dissolved (mg/L)

Potassium, dissolved (mg/L)

Alkalinity (mg/L as CaCO3)

Sulfate, dissolved (mg/L)

Chloride, dissolved (mg/L)

Fluoride, dissolved (mg/L)

Silica, dissolved (mg/L)

Dissolved solids, calculated (mg/L)

Arsenic, total recoverable (ug/L)

Arsenic, dissolved (jig/L) 

Cadmium, total recoverable (ug/L)

Cadmium, dissolved (ng/L)

Copper, total recoverable (ug/L)

Copper, dissolved (|ig/L)

Iron, total recoverable (ug/L) 

Iron, dissolved (ug/L) 

Lead, total recoverable (|ig/L) 

Lead, dissolved (ug/L)

Manganese, total recoverable (ug/L)

Manganese, dissolved (ug/L) 

Zinc, total recoverable (ug/L)

Zinc, dissolved (ug/L)

Sediment, suspended concentration (mg/L)

Sediment, suspended discharge (ton/d)

Sediment, suspended (percent finer than 0.062 mm)

116

91

115

62

52

52

52

18

18

19

18

18

18

18

18

61

61 

61

61

59

60

61 

61 

57 

57

61

61 

61

61

116

116

105

: March

9,370

483

22.0

8.7

210

59

14

12

5.7

133

68

5.6

.4

19

236

110

17 

4

1

500

25

19,000 

190 

100

7

2,000

31 

1,100

39

1370

34,700

98

Mean

MONT.

Median

1985-September 1994

296

160

.0

7.4

67

19

4.8

4.3

1.6

65

21

1.7

.2

12

108

5

4

<.l

3

2

60 

<3

10

1

<3

3

.80

27

1,620

322

9.2

8.1

143

40

10

8.0

2.5

107

43

3.0

.3

15

186

11

6 

2.6

--

53

6

1,690

225 

2 13 

2.7

189

8 

2 100

^

68

745

71

999

340

10.0

8.2

150

42

11

8.4

2.4

116

41

3.0

.3

15

196

8

5

<1

23

5

530 

14 

6

80

7 

40

8

20

58

72

86 Water-Quality, Bed-Sediment, and Biological Data (October 1993 through September 1994) and Statistical Summaries of Data for 

Streams in the Upper Clark Fork Basin, Montana.
Table 24. Statistical summary of water-quality data for the upper Clark Fork basin, Montana, March 1985 

through September 1994 (Continued)

Property or constituent and reporting unit

Number of 

samples

Maximum Minimum Mean Median

12340000-BLACKFOOT RIVER NEAR BONNER. MONT.

Period of record for water-quality data:

Streamflow, instantaneous (flP/s)

Specific conductance, onsite (uS/cm)

Temperature, water (°C)

pH, onsite (standard units)

Hardness, total (mg/L as CaCO3)

Calcium, dissolved (mg/L)

Magnesium, dissolved (mg/L)

Sodium, dissolved (mg/L)

Potassium, dissolved (mg/L)

Alkalinity (mg/L as CaCO3)

Sulfate, dissolved (mg/L)

Chloride, dissolved (mg/L)

Fluoride, dissolved (mg/L)

Silica, dissolved (mg/L)

Dissolved solids, calculated (mg/L)

Arsenic, total recoverable (ug/L)

Arsenic, dissolved (ug/L)

Cadmium, total recoverable (ug/L)

Cadmium, dissolved (ug/L)

Copper, total recoverable (ug/L)

Copper, dissolved (ug/L)

Iron, total recoverable (ug/L)

Iron, dissolved (ug/L)

Lead, total recoverable (ug/L)

Lead, dissolved (ug/L)

Manganese, total recoverable (ug/L)

Manganese, dissolved (ug/L)

Zinc, total recoverable (ug/L)

Zinc, dissolved (ug/L)

Sediment, suspended concentration (mg/L)

Sediment, suspended discharge (ton/d)

Sediment, suspended (percent finer than 0.062 mm)

86

63

86

46

39

39

39

11

11

11

11

11

11

11

11

46

46

46

46

43

44

46

46

42

42

46

46

46

46

86

86

84

March

10,300

294

20.5

8.7

140

37

13

3.4

2.8

140

6.6

1.6

.1

12

154

4

2

2

1

34

7

3,600

100

25

8

180

11

60

15

271

7,540

98

1985-September 1994

344 2,440

131

.0

7.5

55

14

4.9

1.2

.5

76

1.1

.3

<.l

6.8

82

<1

<1

<1

<.l

1

<1

20

<3

<1

<.5

<10

<1

<10

<3

1

1.1

42

206

8.7

8.2

101

26

8.9

2.4

1

109

4.5

.6

--

8.9

120

2 1

2.9

2.5

--

9

22

635

221

26

2 1

240

23

2 14

24

30

501

77

1,020

205

8.5

8.2

95

24

8.4

2.3

.8

96

4.6

.5

<.l

8.6

106

1

<1

<1

<1

7

2

250

14

2

<1

20

2

10

3

8

22

80

TABLE 24 87
Table 24. Statistical summary of water-quality data for the upper Clark Fork basin, Montana, March 1985 

through September 1994 (Continued)

Property or constituent and reporting unit

Number of 

samples

Maximum

12340500-CLARK FORK ABOVE MISSOUL

Period of record for water-quality data:

Streamflow, instantaneous (fVVs)

Specific conductance, onsite (jiS/cm)

Temperature, water (°C)

pH, onsite (standard units)

Hardness, total (mg/L as CaCO3)

Calcium, dissolved (mg/L)

Magnesium, dissolved (mg/L)

Sodium, dissolved (mg/L)

Potassium, dissolved (mg/L)

Alkalinity (mg/L as CaCO3)

Sulfate, dissolved (mg/L)

Chloride, dissolved (mg/L) 

Fluoride, dissolved (mg/L)

Silica, dissolved (mg/L)

Dissolved solids, calculated (mg/L)

Arsenic, total recoverable (fig/L)

Arsenic, dissolved (|ig/L)

Cadmium, total recoverable (ng/L)

Cadmium, dissolved (ng/L)

Copper, total recoverable (fig/L)

Copper, dissolved (ng/L)

Iron, total recoverable (ng/L) 

Iron, dissolved (ng/L) 

Lead, total recoverable (ng/L) 

Lead, dissolved (fig/L)

Manganese, total recoverable (ng/L)

Manganese, dissolved (fig/L) 

Zinc, total recoverable (ng/L) 

Zinc, dissolved (fig/L)

Sediment, suspended concentration (mg/L)

Sediment, suspended discharge (ton/d)

Sediment, suspended (percent finer than 0.062 mm)

82

59

79

39

39

39

39

18

18

18

18

18 

18

18

18

39

39

39

39

37

38

39 

39

34 

34

39

39 

39 

39

82

82

77

Minimum

 A. MONT.

Mean Median

October 1989-September 1994

15,100

399

19.5

8.6

170

46

13

7.7

4.5

136

43

4.2 

.3

16

202

10

7

<1

.1

31

10

3,000

44 

15 

1

170

29 

60 

16

297

7,670

98

720

145

.0

7.9

61

14

5.6

2.4

.9

71

9.3

.9

<.l

9.4

90

2

1

<1

<.l

2

1

70 

<3 

<1

<.5

10

7 

<10 

<3

2

6.1

44

3,760

265

9.2

8.2

124

33

9.7

5.2

1.7

109

23

1.8

2 .2

12

152

4

3

--

--

10

3

479 

2 18

23 

2.7

52

14 

2 19 

26

29

645

87

1,920

280

9.0

8.3

130

35

9.7

5.5

1.5

111

24

1.8 

.2

11

154

4

3

<1

<1

8

2

230 

16 

2 

<1

40

14 

20

5

10

52

89

88 Water-Quality, Bed-Sediment, and Biological Data (October 1993 through September 1994) and Statistical Summaries of Data for 

Streams in the Upper Clark Fork Basin, Montana.
Table 24. Statistical summary of water-quality data for the upper Clark Fork basin, Montana, March 1985 

through September 1994 (Continued)

Property or constituent and reporting unit

12353000-CL

Number of 

samples

Maximum Minimum Mean Median

ARK FORK BELOW MISSOULA. MONT.

Period of record for water-quality data:

Streamflow, instantaneous (ftVs)

Specific conductance, onsite (uS/cm)

Temperature, water (°C)

pH, onsite (standard units)

Hardness, total (mg/L as CaCO3)

Calcium, dissolved (mg/L)

Magnesium, dissolved (mg/L)

Sodium, dissolved (mg/L)

Potassium, dissolved (mg/L)

Alkalinity (mg/L as CaCO3)

Sulfate, dissolved (mg/L)

Chloride, dissolved (mg/L)

Fhioride, dissolved (mg/L)

Silica, dissolved (mg/L)

Dissolved solids, calculated (mg/L)

Arsenic, total recoverable (ug/L)

Arsenic, dissolved (ug/L)

Cadmium, total recoverable (ug/L)

Cadmium, dissolved (ug/L)

Copper, total recoverable (ug/L)

Copper, dissolved (ug/L)

Iron, total recoverable (jig/L)

Iron, dissolved (|ig/L)

Lead, total recoverable (ug/L)

Lead, dissolved (|ig/L)

Manganese, total recoverable (ng/L)

Manganese, dissolved (ug/L)

Zinc, total recoverable (|ig/L)

Zinc, dissolved (|ig/L)

Sediment, suspended concentration (mg/L)

Sediment, suspended discharge (ton/d)

Sediment, suspended (percent finer than 0.062 mm)

58

58

58

58

58

58

58

58

58

57

58

58

58

58

58

7

33

7

33

7

33

7

38

6

31

7

38

7

33

58

58

57

March

19,800

320

20.5

8.8

150

42

11

8.5

3.4

135

34

4.7

.3

15

194

6

6

<1

2

18

9

860

34

4

5

120

18

30

24

85

4,540

93

1985-September 1994

869 4,580

108

.0

7.1

48

13

3.7

2.2

.6

47

6

.3

<.l

5.8

63

2

1

<1

<.l

2

1

90

4

<1

<.5

20

3

<10

<3

1

4.3

35

224

8.5

8.0

105

29

7.8

5.7

1.6

95

20

2.4

2.2

12

135

3

2

--

--

8

3

299

16

«

2.7

39

8

16

27

15

316

74

2,680

244

8.2

8.1

115

32

8.6

6.2

1.8

103

19

2.5

.2

12

146

3

2

<1

<1

7

3

150

16

<1

<5

20

6

10

4

9

70

78

'Multiple minimum reporting levels during the period of record may result in varying values identified with a less-than (<) symbol.

2Value is estimated by using a log-probability regression to predict the values of data less than the minimum reporting level (Helsel and Conn, 1988).

TABLE 24 89
Table 25. Statistical summary of fine-grained bed-sediment data for the upper Clark Fork basin, Montana, 

August 1986 through August 1994

[Fine-grained sediment is material less than 0.064 millimeter in diameter. Concentrations are in micrograms per gram dry 

weight. Symbols: <, less than minimum reporting level; --, indicates either too few samples or insufficient data greater 

than the minimum reporting level to compute statistic. Number of samples represents the number of years that the constituent 

was analyzed, with each year represented by a single mean concentration of composite samples. Values for single samples are 

arbitrarily listed in the "Mean" column]

Number of MaxiConstHuent 

samples mum

Minimum Mean Median

12323600-SILVER BOW CREEK AT OPPORTUNITY. MONT.

Period of record for fine-grained bed-sediment data: 1992-94

Cadmium

Chromium

Copper

Iron

Lead

Manganese

Nickel

Silver

Zinc

3

2

3

3

3

3

2

3

3

38.2

27.6

5,020

39,700

1,030

3,200

16.3

19.6

8,680

27.1 31.5

24.2 25.9

4,560 4,710

34,400 37,200

752 872

1,680 2,430

16.0 16.2

13.7 15.9

6,850 7,850

29.3

4,570

37,500

833

2,410

14.4

8,010

12323750-SILVER BOW CREEK AT WARM SPRINGS. MONT.

Period of record for fine-grained bed-sediment data: 1992-94

Cadmium

Chromium

Copper

Iron

Lead

Manganese

Nickel

Silver

Zinc

3

2

3

3

3

3

2

3

3

12.2

16.7

769

26,000

99

17,700

16.5

1.3

2,220

8.2 10.3

12.8 14.8

536 674

20,400 22,400

74 85

8,150 11,500

15.8 16.2

.3 .8

1,450 1,890

10.6

716

20,800

83

8,590

--

.9

2,010

12323800-CLARK FORK NEAR GALEN. MONT.

Period of record for fine-grained bed-sediment data: 1987, 1991-94

Cadmium

Chromium

Copper

Iron

Lead

Manganese

Nickel

Silver

Zinc

5

2

5

5

5

5

2

5

5

20.1

23.3

2300

39,800

235

15,600

23.2

5.5

3,560

10.5 14.2

22.1 22.7

1,220 1,510

22,600 29,400

116 163

8,540 12,200

21.8 22.5

2.8 3.8

1,820 2,580

13.2

1,270

27,700

145

12,400

3.7

2,580

12324200-CLARK FORK AT DEER LODGE. MONT.

Period of record for fine-grained bed-sediment data: 1986-87, 1990-94

Cadmium

Chromium

Copper

Iron

Lead

Manganese

Nickel

Silver

Zinc

7

2

7

7

7

7

2

7

7

8.3

28.4

4,180

30,100

242

6,020

15.3

7.9

1,730

5.1 6.9

19.5 24.0

837 1,700

22,600 26,700

121 164

1,460 2,880

15.0 15.2

2.4 4.4

977 1360

7.4

-

1,040

26,800

159

2320

~

4.1

1380

90 Water-Quality, Bed-Sediment, and Biological Data (October 1993 through September 1994) and Statistical Summaries of Data for 

Streams In the Upper Clark Fork Basin, Montana.
Table 25. Statistical summary of fine-grained bed-sediment data for the upper Clark Fork basin, Montana, 

August 1986 through August 1994 (Continued)

Number of MaxiConstftuent 

samples mum

Minimum Mean Median

12324590-LITTLE BLACKFOOT RIVER NEAR GARRISON. MONT.

Period of record for fine-grained bed-sediment data: 1986-87, 1994

Cadmium

Chromium

Copper

Iron

Lead

Manganese

Nickel

Silver

Zinc

3

1

3

3

3

3

1

3

3

.9

-

85

26,400

53

2,700

.9

180

.2 .6

22.1

38 54

16,100 22,100

37 43

907 1,550

13.6

<.5 .4

161 170

.7

40

23,800

40

1,040

<.5

170

12324680-CLARK FORK AT GOLDCREEK. MONT.

Period of record for fine-grained bed-sediment data: 1992-94

Cadmium

Chromium

Copper

Iron

Lead

Manganese

Nickel

Silver

Zinc

3

2

3

3

3

3

2

3

3

6.2

31.9

1,030

26,400

152

2,610

17.0

3.7

1,320

5.4 5.8

31.6 31.8

653 804

20,500 23,500

93 117

1,180 2,080

15.0 16.0

2.3 2.9

1,120 1,210

5.8

729

23,700

107

2,450

2.8

1,210

12331500-FUNT CREEK NEAR DRUMMOND. MONT.

Period of record for fine-grained bed-sediment data: 1986, 1989, 1992-94

Cadmium

Chromium

Copper

Iron

Lead

Manganese

Nickel

Silver

Zinc

5

2

5

5

5

5

2

4

5

3.2

24.3

73

28,100

240

5,510

12.5

7.8

727

<1.0 2.2

21.1 22.7

55 61

21,100 23,600

151 193

2,710 3,850

11.7 12.1

5.0 6.4

610 667

2.3

57

22,900

189

3,560

6.5

672

12331800-CLARK FORK NEAR DRUMMOND. MONT.

Period of record for fine-grained bed-sediment data: 1986-87, 1991-94

Cadmium

Chromium

Copper

Iron

Lead

Manganese

Nickel

Silver

Zinc

6

2

6

6

6

6

2

6

6

5.4

30.1

614

24,700

135

2360

15.7

3.5

1,230

4.1 4.7

17.0 23.6

469 544

16,500 21,200

85 103

1,220 1,840

14.0 14.9

2.1 2.8

1,030 1,110

4.6

551

21,600

100

1,910

2.8

1,110

TABLE 25 91
Table 25. Statistical summary of fine-grained bed-sediment data for the upper Clark Fork basin, Montana, 

August 1986 through August 1994 (Continued)

Constituent

Number of 

samples

Maximum

Minimum Mean Median

Cadmium

Chromium

Copper

Iron

Lead

Manganese

Nickel

Silver

Zinc

12334S10-ROCK CREEK NEAR CLINTON. MONT. 

Period of record for fine-grained bed-sediment data: 1986-89,1991-94

19.3 16.5

15 3

21,400 13,100

16 <3

598 126

12.7

58

10.8

36

17.9

11

17,200

8

316

11.8

47

13

17,600

9

278

48

Cadmium

Chromium

Copper

Iron

Lead

Manganese

Nickel

Silver

Zinc

12334550-CLARK FORK AT TURAH BRIDGE. NEAR BONNER. MONT.

Period of record for fine-grained bed-sediment data: 1986, 1991-94

5

2

5

5

5

5

2

5

5

5.2

26.7

561

23,200

115

1,670

15.9

2.9

1,160

3.1

15.3

300

15,100

63

671

12.0

1.3

775

3.8

21.0

401

18,700

82

1,140

14.0

2.1

934

3.6

323

17300

74

1,260

2.1

880

Cadmium

Chromium

Copper

Iron

Lead

Manganese

Nickel

Silver

Zinc

12340000-BLACKFOOT RIVER NEAR BONNER. MONT. 

Period of record for fine-grained bed-sediment data: 1986-87,1991,1993-94

<1.2 

15.3 

25

18,100 

20 

535 

12.7

71

<3 

15.1 

16

12,400 

10 

298 

11.7

54

<1.2 

15.2 

21

15300 

12 

454 

12.2

61

21

15,200

11

486

60

12353000-CLARK FORK BELOW MISSOULA. MONT.1

Period of record for fine-grained bed-sediment data: 1986, 1990-94

Cadmium

Chromium

Copper

Iron

Lead

Manganese

Nickel

Silver

Zinc

6

2

6

6

6

6

2

6

6

2.6

21.5

293

21,000

58

2,530

14.1

2.1

675

1.1

18.8

96

14,500

33

752

133

.4

319

1.6

20.2

162

18,200

42

1,500

13.7

1.1

427

1.5

124

19,100

37

1,214

1.0

380

1 Samples collected about 30 miles downstream of water-quality stations to conform to previous sampling location.

92 Water-Quality, Bed-Sediment, and Biological Data (October 1993 through September 1994) and Statistical Summaries of Data for 

Streams in the Upper Clark Fork Basin, Montana
Table 26. Statistical summary of bulk bed-sediment data for the upper Clark Fork basin, 

Montana, August 1993 through August 1994

[Concentrations are in micrograms per gram dry weight Symbols: <, less than minimum reporting level; 

--, indicates too few samples to compute statistic. Number of samples represents the number of years that the 

constituent was analyzed, with each year represented by a single mean concentration of composite samples. 

Values for single samples are arbitrarily listed in the "Mean" column]

Constituent

Number of 

samples

Maximum

Minimum Mean

12323600-SILVER BOW CREEK AT OPPORTUNITY. MONT.

Period of record for bulk bed-sediment data: 1993-94

Cadmium

Chromium

Copper

Iron

Lead

Manganese

Nickel

Silver

Zinc

12.7

14.9

1,550

27,200

300

1,670

8.9

4.8

3,420

6.7

9.6

831

18,600

248

671

6.0

3.9

2,050

9.7

12.2

1,190

22,900

274

1,170

7.4

4.3

2,730

123237SQ-SILVER BOW CREEK AT WARM SPRINGS. MONT. 

Period of record for bulk bed-sediment data: 1993

Cadmium 1 1.2 

Chromium 1 - -- 9.9 

Copper 1 - -- 111 

Iron 1 -- - 9,160 

Lead 1 -- -- 33 

Manganese 1 -- 543 

Nickel 1 - -- 8.1 

Silver 1 - -- <.5 

Zinc 1 - -- 303

123238QQ-CLARK FORK NF.AR GAT.KN. MONT. 

Period of record for bulk bed-sediment data: 1993-94

Cadmium

Chromium

Copper

Iron

Lead

Manganese

Nickel

Silver

Zinc

6.0

18.4

685

25,900

87

5,410

12.5

1.6

1,280

1.5

4.2

223

9,930

41

1,280

4.9

.7

498

3.7

11.3

454

17,900

64

3350

8.7

1.1

890

12324200-CLARK FORK AT DEER LODGE. MONT. 

Period of record for bulk bed-sediment data: 1993-94

Cadmium

Chromium

Copper

Iron

Lead

Manganese

Nickel

Silver

Zinc

2.4

16.1

383

17,900

85

2,060

10.2

1.6

599

2.0 

13.3 

281 

13,200 

45 

998 

7.7 

<.7 

456

2.2 

14.7 

332 

15,500 

65 

1,530

8.9 

<1.2 

528

TABLE 26 93
Table 26. Statistical summary of bulk bed-sediment data for the upper Clark Fork basin, 

Montana, August 1993 through August 1994 (Continued)

Number of MaxiConstltuent Minimum

samples mum

Mean

12324590-LITTI.K RI.ACKFOOT RIVER NEAR GARRISON. MONT.

Cadmium

Chromium

Copper

Iron

Lead

Manganese

Nickel

Silver

Zinc

Cadmium

Chromium

Copper

Iron

Lead

Manganese

Nickel

Silver

Zinc

Cadmium

Chromium

Copper

Iron

Lead

Manganese

Nickel

Silver

Zinc

Cadmium

Chromium

Copper

Iron

Lead

Manganese

Nickel

Silver

Zinc

Period of record for bulk bed-sediment data: 1994

1

1

1

1

1

1

1 _

1

1

12324680 CLARK FORK AT GOLDCREEK. MONT.

Period of record for bulk bed-sediment data: 1993-94

2 2.4 2.3

2 23.4 17.6

2 370 282

2 18,600 15,500

2 72 46

2 1,190 649

2 12.4 9.1

2 1.6 <.7

2 676 549

12331500 FLINT CREEK NEAR DRUMMOND. MONT.

Period of record for bulk bed-sediment data: 1993-94

2 1.7 .3

2 10.3 4.9

2 25 19

2 13,400 8,630

2 79 51

2 3,200 1,150

2 6.0 5.8

2 3.9 3.3

2 284 190

12331800-CLARK FORK NEAR DRUMMOND. MONT.

Period of record for bulk bed-sediment data: 1993-94

2 1.8 1.5

2 16.9 13.8

2 276 173

2 15,900 14,100

2 61 35

2 820 711

2 11.0 9.0

2 1.7 .7

2 621 434

<1.2

14.7

19

15,600

12

420

8.6

<.7

73

2.4

20.5

326

17,100

59

920

10.7

<1.2

613

1.0

7.6

22

11,000

65

2,170

5.9

3.6

237

1.6

15.4

225

15,000

48

766

10.0

1.2

527

94 Water-Quality, Bed-Sediment, and Biological Data (October 1993 through September 1994) and Statistical Summaries of Data for 

Streams in the Upper Clark Fork Basin, Montana.
Table 26. Statistical summary of bulk bed-sediment data for the upper Clark Fork basin, 

Montana, August 1993 through August 1994 (Continued)

Constituent

Number of 

samples

Maximum

Minimum Mean

Cadmium

Chromium

Copper

Iron

Lead

Manganese

Nickel

Silver

Zinc

12334510-ROCK CREEK NEAR CLINTON. MONT. 

Period of record for bulk bed-sediment data: 1993-94

2

10.8

7

9,840

5

195 

6.2 

<.7 

29

6.6

4

6,380

5

91

4.9

.1

16

8.7

6

8,110

5

143 

5.5 

<.7 

22

1233455(K-CLARK FORK AT TURAH BRIDGE. NEAR BONNER. MONT. 

Period of record for bulk bed-sediment data: 1993-94

Cadmium

Chromium

Copper

Iron

Lead

Manganese

Nickel

Silver

Zinc

1.8 

15.5 

182 

13,200 

37 

487 

8.8 

<.7 

510

.5

6.9

122

10,700

30

414

6.4

.3

345

1.2 

11.2 

152 

11,900 

34 

451 

7.6 

<.7 

428

Cadmium

Chromium

Copper

Iron

Lead

Manganese

Nickel

Silver

Zinc

123400QO-BLACKFOQT RIVER NEAR BQNNER MONT. 

Period of record for bulk bed-sediment data: 1993-94

17.7

19

6.7

14

16,600

10

305

9.8

<.7 

58

10300

8

179

7.6

<.5 

33

123530QO-CLARK FORK BE! ,OW MISSOUTA. MONT.1 

Period of record for bulk bed-sediment data: 1993-94

12.2 

16

13,400 

9

242 

8.7 

<.7 

46

Cadmium

Chromium

Copper 

Iron

Lead

Manganese 

Nickel

Silver

Zinc

2

2

2 

2

2

2 

2

2

2

<1.2

8.7

77 

10,200

19

351 

7.1

<.7

172

.5

4.4

22 

6,160

8

223 

3.5

.5

88

<1.2

6.5

50 

8,180

14

287 

5.3

<.7

130

1 Samples collected about 30 miles downstream of water-quality station to conform to previous 

sampling location.

TABLE 26 95
Table 27. Statistical summary of biological data for the upper Clark Fork basin, Montana, August 1986 through 

August 1994

[Concentrations are in micrograms per gram dry weight Symbols: <, less than minimum reporting level; -, indicates either 

too few samples or insufficient data greater than the minimum reporting level to compute statistic, or element not analyzed. 

Number of composite samples represents the total of all individual composite samples collected for every year that the constituent 

was analyzed Values for single samples are arbitrarily listed in the "Mean" column. Statistical summary not presented for Silver 

Bow Creek at Warm Springs which has been sampled only one time in 1994]

Number of MaxiConstrtuent composite Minimum 

mum 

samples

Mean Median

12323600-SILVER BOW CREEK AT OPPORTUNITY. MONT.

Cadmium

Chromium

Copper

Iron

Lead

Manganese

Nickel

Zinc

Cadmium

Chromium

Copper

Iron

Lead

Manganese

Nickel

Zinc

Cadmium

Chromium

Copper

Iron

Lead

Manganese

Nickel

Zinc

Cadmium

Chromium

Copper

Iron

Lead

Manganese

Nickel

Zinc

Period of record for biological data: 1992, 94

Hvdropsyche morosa group

4 5.2 4.1

4 8.0 1.0

4 462 269

4 1,180 834

4 21.0 19.5

4 718 375

4 2.1 1.6

4 989 749

Hvdropsvche tana

5 7.5 4.8

5 11.5 .9

5 339 10.5

5 1,520 1,000

5 20.8 15.6

5 969 415

5 1.8 1.4

5 1,070 760

12323800-CLARK FORK NEAR GALEN. MONT.

Period of record for biological data: 1987, 1991-94

Hvdropsvche spp.

4 3.5 2.6

4

4 154 135

4 1,540 1,190

4 13.5 10.5

4

4

4 329 279

Hvdropsvche morosa group2

13 2.7 1.3

13 3.3 .8

13 184 85

13 1,500 901

13 9.3 2.8

13 3,960 1,690

13 3.1 1.0

13 312 190

4.6

3.9

347

992

19.9

530

1.8

804

6.4

5.0

192

1,140

18.1

700

1.6

951

3.0

148

1,400

12.2

--

308

2.1

1.7

135

1,250

7.1

2,700

1.8

259

4.6

3.3

328

978

19.8

615

1.8

785

6.9

1.6

289

1,080

17.6

710

1.7

1,030

3.0

152

1,450

12.4

~

313

2.0

1.7

118

1,280

7.2

2360

1.9

251

96 Water-Quality, Bed-Sediment, and Biological Data (October 1993 through September 1994) and Statistical Summaries of Data for 

Streams in the Upper Clark Fork Basin, Montana.
Table 27. Statistical summary of biological data for the upper Clark Fork basin, Montana, August 1986 through 

August 1994 (Continued)

Cadmium

Chromium

Copper

Iron

Lead

Manganese

Nickel

Zinc

Cadmium

Chromium

Copper

Iron

Lead

Manganese

Nickel

Zinc

Cadmium

Chromium

Copper

Iron

Lead

Manganese

Nickel

Zinc

Cadmium

Chromium

Copper

Iron

Lead

Manganese

Nickel

Zinc

Cadmium

Chromium

Copper

Iron

Lead

Manganese

Nickel

Zinc

Number of

MaxiConstituent composite Minimum Mean

mum

samples

12323800-CLARK FORK NEAR GALEN. MONT.-Conttaued

Period of record for biological data: 1987, 1991-94

Hvdropsvche occidentalis

8 1.6 1.0 1.3

8 6.6 .7 1.9

8 84.1 68.5 77.4

8 1,190 642 888

8 7.3 3.7 4.7

8 4,070 2,590 3,310

8 3.5 1.2 1.9

8 278 188 227

12324200-0 ARK FORK AT DEER LODGE, MONT.

Period of record for biological data: 1986-87, 1990-94

Hvdropsvche spp.

3 2.0 1.2 1.6

3

3 222 103 145

3 2,220 1,110 1,520

3 15.0 5.6 8.8

3

3

3 203 185 195

Hvdropsvche morosa group

14 2.3 .8 1.5

14 2.6 .4 1.5

14 136 55 95

14 1,880 98 792

14 18.2 4.3 8.6

14 2,950 499 1,170

14 1.8 .3 1.1

14 391 132 188

Hydropsvche occidentalis

10 2.7 .8 1.4

10 2.3 .6 1.7

10 134 49 102

10 1,580 557 1,280

10 13.4 6.3 10.1

10 3,330 1,690 2,610

10 2.5 1.1 1.6

10 299 196 243

12324590-LITTLE BLACKFOOT RIVER NEAR GARRISON. MONT.

Period of record for biological data: 1987, 1994

Hydropsvche cockereltt

1 - -- .6

1 - - 1.6

1 -- -- 28.4

1 - - 478

1 -- - 3.6

1 - - 399

1 -- - 1.2

1 -- - 123

Median

1.2

1.4

77.2

878

4.0

3,250

1.9

228

1.6

~

111

1,240

5.7

--

~

197

1.5

1.8

92

573

8.4

691

1.1

180

1.3

1.9

111

1310

9.9

2,590

1.6

221

~

~

--

~

~

~

TABLE 27 97
Table 27. Statistical summary of biological data for the upper Clark Fork basin, Montana, August 1986 through 

August 1994 (Continued)

Constituent

Number of 

composite 

samples

MaxiMinimum Mean 

mum

Median

Cadmium

Chromium

Copper

Iron

Lead

Manganese

Nickel

Zinc

Cadmium

Chromium

Copper

Iron

Lead

Manganese

Nickel

Zinc

Cadmium

Chromium

Copper

Iron

Lead

Manganese

Nickel

Zinc

Cadmium

Chromium

Copper

Iron

Lead

Manganese

Nickel

Zinc

Cadmium

Chromium

Copper

Iron

Lead

Manganese

Nickel

Zinc

12324590-LITTLE BLACKFQOT RIVER NEAR GARRISON. MONT.-Conrinued

Period of record for biological data: 1987,1994

Hvdroosvche occidentaKs i

1

l

l

1

1

1

1

Arctopsvche grandis

9 .4 .2

9 .8 .6

9 14.0 9.1

9 325 177

9 1.3 .5

9 596 318

9 .6 .4

9 179 113

Claassenia sabulosa

4 .3 .1

4 .8 .7

4 34.0 20.0

4 200 98

4 <.7 <.4

4 62.1 46.7

4 .7 .5

4 233 191

<.7

1.3

15.1

426

<3.7

434

.8

110

.3

.7

11.5

242

.8

471

.5

146

.2

.8

27.9

138

<.6

53.4

.6

206

12324680-CLARK FORK AT GOLDCREEK. MONT.

Period of record for biological data: 1992-94

Hvdropsvche morosa group

7 2.1 .6

7 4.2 .7

7 72.9 33.5

7 1320 589

7 6.0 2.4

7 1,030 588

7 1.5 .6

7 201 152

Hydropsyche occidentals

3 1.2 .7

3 1.7 .4

3 55.5 32.9

3 1,180 585

3 6.0 5.4

3 1,800 1,350

3 1.0 .8

3 207 184

1.5

2.1

61.7

868

4.6

745

1.2

182

.8

.9

42.0

820

5.7

1,580

.9

193

.3

.8

11.8

230

.8

492

.5

145

.2 

.8

28.8 

127 

<.6 

51.3 

.5 

201

1.5

1.4

66.6

655

4.8

713

1.2

188

.7

.5

37.6

690

5.6

1,590

.8

188

98 Water-Quality, Bed-Sediment, and Biological Data (October 1993 through September 1994) and Statistical Summaries of Data for 

Streams in the Upper Clark Fork Basin, Montana.
Table 27. Statistical summary of biological data for the upper Clark Fork basin, Montana, August 1986 through 

August 1994 (Continued)

Number of

MaxiConstltuent composite Minimum

mum

samples

Mean Median

12324680-CLARK FORK AT GOLDCREE1C MONT.-Cnntfnued

Cadmium

Chromium

Copper

Iron

Lead

Manganese

Nickel

Zinc

Cadmium

Chromium

Copper

Iron

Lead

Manganese

Nickel

Zinc

Period of record for biological data: 1992-94

Arctopsvche grandis

3 6.6 1.4

3 2.3 1.0

3 39.9 31.5

3 476 387

3 3.8 2.9

3 1,100 1,030

3 1.0 .6

3 309 175

Claassenia sabulosa

5 1.0 .6

5 1.6 .3

5 66.6 33.0

5 230 63.0

5 1.2 .8

5 179 65.1

5 .7 .2

5 296 166

3.2

1.4

34.5

445

3.2

1,070

.7

226

.8

.8

51.4

153

.9

121

.4

239

1.6

1.0

32.0

473

3.0

1,080

.6

195

.9

.8

49.4

178

.9

117

.3

257

12331500-FLINT CREEK NEAR DRUMMOND. MONT.

Cadmium

Chromium

Copper

ton

Lead

Manganese

Nickel

Zinc

Cadmium

Chromium

Copper

lion

Lead

Manganese

Nickel

Zinc

Cadmium

Chromium

Copper

Iron

Lead

Manganese

Nickel

Zinc

Period of record for biological data: 1986, 1992-94

Hydropsyche morosa group

3 .4 .4

3 1.2 1.0

3 28.3 16.1

3 1,500 1,140

3 11.1 3.1

3 1,440 912

3 2.2 1.5

3 193 113

Hvdropsvche occidentals

3 <2.9 <-l

3 17.6 .7

3 19.2 15.1

3 1,690 912

3 24.0 5.8

3 1,750 1,400

3 6.9 .8

3 195 128

Hydropsyche tana

2 <1.2 <.l

2 10.3 .6

2 16.0 5.4

2 1320 729

2 15.3 5.0

2 1,400 1,180

2 3.1 .5

2 139 107

.4

1.1

21.3

1,290

6.6

1,140

1.8

148

<1.3

6.6

17.2

1350

12.4

1,540

3.7

159

<.7

5.4

10.7

1,020

10.2

1,290

1.8

123

.4

1.0

19.5

1,220

5.6

1,070

1.6

139

<.9

1.6

17.2

1,450

7.5

1,450

3.5

155

<.7

5.4

10.7

1,020

10.2

1,290

1.8

123

TABLE 27 99
Table 27. Statistical summary of biological data for the upper Clark Fork basin, Montana, August 1986 through 

August 1994 (Continued)

Cadmium

Chromium

Copper

Iron

Lead

Manganese

Nickel

Zinc

Cadmium

Chromium

Copper

Iron

Lead

Manganese

Nickel

Zinc

Cadmium

Chromium

Copper

Iron

Lead

Manganese

Nickel

Zinc

Cadmium

Chromium

Copper

Iron

Lead

Manganese

Nickel

Zinc

Cadmium

Chromium

Copper

Iron

Lead

Manganese

Nickel

Zinc

Number of

MaxiConstituent composite Minimum Mean

mum

samples

12331500-FLINT CREEK NEAR DRUMMOND. MONT.-Contlnued

Period of record for biological data: 1986, 1992-94

Arctopsvche frandis

16 .6 .2 .4

16 4.7 .6 2.1

16 19.8 9.7 14.6

16 2,460 606 1,200

16 17.5 4.1 9.5

16 2,480 1,140 1,720

16 2.3 .6 1.2

16 275 151 197

12331800-CLARK FORK NEAR DRUMMOND. MONT.

Period of record for biological data: 1986, 1991-94

Hvdropsvche spp.

1 - - 2.6

\

1 - - 85.0

1 -- - 940

1 - - 9.1

1

\

1 - -- 260

Hydropsvche morosa group2

10 1.4 .7 1.1

10 2.8 .4 1.9

10 57.4 37.9 50.0

10 1,730 506 1,170

10 10.8 5.1 7.8

10 1,940 549 1,230

10 1.7 .5 1.1

10 250 164 213

Hydropsvche occidentalis

1 1.4 .6 1.0

7 8.1 .4 2.7

7 57.2 13.3 44.7

7 1,800 424 1,100

7 12.5 5.9 10.6

7 2,920 619 1,810

7 2.0 .5 1.3

7 283 170 232

Arctopsvche grandis

8 1.4 .7 1.0

8 1.0 .4 .8

8 44.3 18.2 26.6

8 931 240 543

8 11.8 2.1 6.1

8 2,010 641 1,230

8 .7 .3 .6

8 308 142 206

Median

.3

1.7

14.8

1,060

8.1

1,480

1.1

182

~

--

~

--

~

~

1.2

1.9

52.7

1,410

7.3

1,280

1.4

228

1.1

2.3

47.5

757

12.0

1,240

1.3

223

.9

.9

22.7

529

4.6

1,300

.6

196

100 Water-Quality, Bed-Sediment, and Biological Data (October 1993 through September 1994) and Statistical Summaries of Data 

for Streams In the Upper Clark Fork Basin, Montana.
Table 27. Statistical summary of biological data for the upper Clark Fork basin, Montana, August 1986 through 

August 1994 (Continued)

Number of MaxiConsthuent composite Minimum 

mum 

samples

Mean Median

12331800-CLARK FORK NEAR DRUMMOND. MONT.-Continued

Cadmium

Chromium

Copper

Iron

Lead

Manganese

Nickel

Zinc

Cadmium

Chromium

Copper

Iron

Lead

Manganese

Nickel

Zinc

Cadmium

Chromium

Copper

Iron

Lead

Manganese

Nickel

Zinc

Cadmium

Chromium

Copper

Iron

Lead

Manganese

Nickel

Zinc

Cadmium

Chromium

Copper

Iron

Lead

Manganese

Nickel

Zinc

Period of record for biological data: 1986, 1991-94

Claassenia sabulosa

16 2.1 .3

16 3.3 .3

16 130 18

16 4,880 76

16 41.6 .4

16 270 45.9

16 1.1 .2

16 469 140

1 233451 0-ROCK CREEK NEAR CLINTON. MONT.

Period of record for biological data: 1987, 1991-94

Hydropsvche cockerelK

2 <.2 <.2

2 1.0 .9

2 6.6 6.0

2 497 485

2 <1.1 <1.1

2 208 192

2 <.4 <.4

2 86 82

Hvdropsvche occidentalis

3 <1.0 <.3

3 2.4 .9

3 17.6 10.2

3 652 520

3 <1.6 .2

3 268 169

3 1.7 .6

3 144 117

Arctopsvche grandis

18 .3 .1

18 2.9 .5

18 12.3 4.7

18 571 191

18 .7 .4

18 328 113

18 1.6 .2

18 189 84

Claassenia sabulosa

9 .3 .1

9 1.8 .5

9 37.2 18.1

9 115 50.0

9 <.5 <.5

9 43.0 16.0

9 .9 .2

9 242 156

.9

1.0

58.4

475

4.5

132

.5

264

<.2

.9

6.3

491

<1.1

200

<.4

84

<.5

1.9

12.8

606

<1.6

217

1.2

128

.2

1.1

7.6

372

.5

195

.6

119

.2

1.0

25.9

85.0

<.5

27.0

.5

201

.8

.8

50.0

149

4.0

144

.3

243

<.2

.9

6.3

491

<1.1

200

<.4

84

<.3

2.3

10.6

648

<1.6

215

1.4

122

.1

.9

7.3

351

.5

210

.4

118

.2

.8

27.1

84.0

<.5

27.0

.4

211

TABLE 27 101
Table 27. Statistical summary of biological data for the upper Clark Fork basin, Montana, August 1986 through 

August 1994 (Continued)

Constituent

Number of 

composite 

samples

MaxiMinimum Mean 

mum

Median

12334550-CLARK FORK AT TURAH BRIDGE. NEAR BONNER MONT.

Period of record for biological data: 1991-94 

Hvdroosvche morosa group

Cadmium

Chromium

Copper

Iron

Lead

Manganese

Nickel

Zinc

Cadmium

Chromium

Copper

Iron

Lead

Manganese

Nickel

Zinc

Cadmium

Chromium

Copper

Iron

Lead

Manganese

Nickel

Zinc

Cadmium

Chromium

Copper

Iron

Lead

Manganese

Nickel

Zinc

8

8

8

8

8

8

8

8

1.4

8.0

42.4

1,100

4.4

788

2.6

224

.6

1.0

26.4

688

2.5

426

.7

169

.8

2.2

35.2

951

3.2

540

1.2

184

.7

1.6

35.7

1,010

2.7

529

1.1

180

Hydroosvche occidental 

6

6

6

6

6

6

6

6

11

11

11

11

11

11

11

11

10

10

10

10

10

10

10

10

.9

2.4

41.8

1,130

8.2

1,510

1.1

231

Arctopsvche grandis

1.9

2.1

28.9

794

3.9

825

.9

240

Claassenia sabulosa

1.7

2.0

72.0

181

1.1

96.0

.6

268

.3

.6

34.1

472

3.0

454

.6

145

.6

.6

20.1

420

2.1

351

.4

155

.3

.4

43.0

59.0

.3

42.0

.1

166

.6

1.6

36.5

849

5.1

852

.9

193

.9

1.3

23.9

574

2.9

646

.7

184

.7

1.0

54.0

99.0

.6

65.0

.3

216

.6

1.5

35.0

869

3.8

568

.9

188

.7

1.2

23.5

509

2.9

505

.6

171

.5

.9

53.0

96.0

.7

63.0

.3

212

Cadmium

Chromium

Copper

Iron

Lead

Manganese

Nickel

Zinc

12340QQft-BLACKFOQT RIVER NEAR BONNER. MONT.

Period of record for biological data: 1986-87,1991,1993

Hvdroosvche occidentatis

7

7

7

7

7

7

7

7

2.2

2.1

20.6

1,530

1.9

474

1.7

150

.8

1.2

13.2

1,060

1.1

414

.9

130

1.2

1.7

15.4

1,300

1.5

447

1.2

142

1.0

1.6

14.7

1300

1.6

452

1.2

145

102 Water-Quality, Bed-Sediment, and Biological Data (October 1993 through September 1994) and Statistical Summaries of Data 

for Streams in the Upper Clark Fork Basin, Montana.
Table 27. Statistical summary of biological data for the upper Clark Fork basin, Montana, August 1986 through 

August 1994 (Continued)

Number of

MaxiConstftuent composite Minimum

mum

samples

Mean Median

12340000-BLACKFOOT RIVER NEAR BONNER. MONT.-Continued

Period of record for biological data: 1986-87, 1991, 1993

Cadmium

Chromium

Copper

Iron

Lead

Manganese

Nickel

Zinc

Cadmium

Chromium

Copper

Iron

Lead

Manganese

Nickel

Zinc

Arctopsvche grandis

6 <.4 <.l

6

6 17.9 12.1

6 483 108

6 <2.1 <.6

6

6

6 366 123

Claassenia sabulosa

9 .6 .1

9

9 51.0 32.0

9 199 68.0

9 <.9 <.3

9

9

9 233 184

<.3

14.3

327

<1.1

-

223

.4

43.0

116

<.5

203

<.3

13.1

431

<1.5

~

~

136

.5

~

44.0

113

<.5

-

197

12353000-CLARK FORK BELOW M ISSOULA. MONT.1

Cadmium

Chromium

Copper

Iron

Lead

Manganese

Nickel

Zinc

Cadmium

Chromium

Copper

Iron

Lead

Manganese

Nickel

Zinc

Cadmium

Chromium

Copper

Iron

Lead

Manganese

Nickel

Zinc

Period of record for biological data: 1986, 1990-94

Hvdropsvche morosa group2

14 .7 .2

14 3.4 .8

14 39.3 12.4

14 1390 648

14 3.6 1.2

14 1,180 580

14 1.5 .5

14 172 99

Hvdropsvche occidentalis

1 .9 .2

7 1.6 .2

7 30.5 18.9

7 1,420 482

7 2.4 .7

7 1,460 667

7 2.2 .5

7 193 116

Arctopsvche grandis

6 .9 .3

6 2.7 .5

6 22.0 9.4

6 525 343

6 1.9 1.0

6 1,090 511

6 1.0 .4

6 169 106

.5

2.0

26.8

1,070

2.0

778

1.1

147

.3

.6

22.8

793

1.6

974

1.0

139

.5

1.1

15.8

435

1.4

773

.7

139

.6

1.9

28.3

1,080

1.8

664

1.2

165

.2

.4

20.5

731

1.8

959

1.7

130

.4

1.0

16.7

432

1.3

712

.7

140

TABLE 27 103
Table 27. Statistical summary of biological data for the upper Clark Fork basin, Montana, August 1986 through 

August 1994 (Continued)

Constituent

Number of 

composite 

samples

MaxiMinimum Mean 

mum

Median

123S3000-CLARK FORK BELOW MISSOULA. MONT^-Contlnucd

Period of record for biological data: 1986,1990-94

Claassenia sabulosa

Cadmium

Chromium

Copper 

Iron

Lead

Manganese 

Nickel

Zinc

19

19

19 

19

19

19 

19

19

.7

1.2

58.0

127

.6

168 

.3

286

.2

.05

31.0 

67.0

.1

49.0 

.1

146

.4

.6

45.0 

86.0

.3

100

.2

202

.3

.3

46.0 

81.0

.4

75.0 

.2

200

Samples collected about 30 miles downstream of water-quality station to conform to previous sampling location. 

2Includes more than one species within the Hydropsyche morosa group.

104 Water-Quality, Bed-Sediment, and Biological Data (October 1993 through September 1994) and Statistical Summaries of Data 

for Streams in the Upper Clark Fork Basin, Montana.

 sV U.S. GOVERNMENT PRINTING OFFICE: 1995 676-721