Cover. Old Faithful Geyser during one of its intermittent eruptions of steam and hot 

water, southwestern Yellowstone National Park, Wyoming. 
Monitoring of Thermal Activity inl 

Southwestern Yellowstone National Park 

and Vicinity, 1980-1993 

By Irving Friedman, Daniel R. Norton, and Roderick A. Hutchinson 

U.S. GEOLOGICAL SURVEY BULLETIN 2067 

UNITED STATES GOVERNMENT PRINTING OFFICE, WASHINGTON: 1993 
U.S. DEPARTMENT OF THE INTERIOR 

BRUCE BABBITT, Secretary 

U.S. GEOLOGICAL SURVEY 

Robert M. Hirsch, Acting Director 

For sale by U.S. Geological Survey, Map Distribution 

Box 25286, MS 306, Federal Center 

Denver, CO 80225 

Any use of trade, product, or firm names in this publication is for descriptive purposes only and 

does not imply endorsement by the U.S. Government. 

Library of Congress Cataloging-in-Publication Data 

Friedman, Irving, 1920-

Monitoring of thennal activity in southwestern Yellowstone National Park and vicinity, 

1980-1993 I by Irving Friedman, Daniel R. Norton, and Roderick A. Hutchinson. 

p. em.- (U.S. Geological Survey bulletin; 2067) 

Includes bibliographical references. 

Supt. of Docs. no.: I 19.3:2067 

1. Hot springs-Yellowstone National Park. 2. Yellowstone National Park. I. 

Norton, Daniel R. ll. Hutchinson, R. A. III. Title. IV. Series. 

QE75.B9 no. 2067 

[GB1198.3.Y4] 

557.3 s-dc20 

[551.2'3'0978752] 93-34285 

CIP 
CONTENTS 

Abstract .............................................................................................................................. . 

Introduction ........................................................................................................................ . 

Stream Monitoring in Southwestern Yellowstone National Park ...................................... . 

Initial Investigations ................................................................................................. . 

Subsequent Investigations ........................................................................................ . 

Calibration ofWeirs and Staff Gauges .................................................................... . 

Results ...................................................................................................................... . 

1 

1 

2 

2 

4 

10 

10 

Conclusions . ... . . . ... . .. . . . . . . . ... ... . .. .. . . . . . . . .. . . . . . . . ... ... ........ .. . . .. . . . . . . . . ................. ..... .. .... .. ...... 11 

Measurement of Thermally Derived Chloride in the Island Park Geothermal Area, 

Idaho................................................................................................................................ 15 

Conclusions . . ............... .. . ........... .. ..... .. . . . . .. . ... .. . . . . .. ...... ... . . . . . . . ........... .. . . . . . ............. .. .... 17 

Acknowledgments............................................................................................................... 18 

References Cited................................................................................................................. 18 

FIGURES 

1. Map showing the southwestern portion of Yellowstone National Park and the Island Park 

Geothermal Area ........ .. . . . .................. ... ... .. . .. . . . . . . . .. . . . . . . . ... . . . . . . .. . . . .... .. . . . . . . . .................. ......... .. . . . ............. .. . . . . . . . ... .. . . . 2 

2. Aerial photograph showing thermal features adjacent to Boundary Creek in Yellowstone National Park.......... 3 

3. Aerial photograph of the Monitor Creek Thermal Area showing monitoring sites ....................... .... .. ................. 4 

4. Diagrams of physical data from Weir 3, Monitor Creek Thermal Area, plotted as a function of time................. 5 

5. Map showing sites where chloride flux was measured in southwestern Yellowstone National Park................... 6 

6. Map of the Henrys Fork drainage in the Island Park Geothermal Area, showing instantaneous chloride flux 

at various springs and streams............................................................................................................................... 7 

7. Photographs of Weir 4 in the Middle Boundary Creek Thermal Area, and Weir 8 in the Crescent Ridge 

Thermal Area......................................................................................................................................................... 9 

8. Aerial photograph of the Middle Boundary Creek Thermal Area showing monitoring sites............................... 10 

9-12. Plots of: 

9. Discharge and chloride flux at presumed base-flow conditions for weirs located in Monitor Creek 

Thermal Area................................................................................................................................................ 13 

10. Discharge and chloride flux at presumed base-flow conditions for weirs located in Middle Boundary 

Creek Thermal Area . . . . . . . . ......... .. . . . . . . . .. . . ... . . .. . . . . ............ .. . . . . . . . ... ............... ....... .. ... . . . . . . .. . . . . . . . ... . . .... .. . . . . . .......... 14 

11. Discharge and chloride flux at presumed base-flow conditions for weir located in Crescent Ridge 

Thermal Area................................................................................................................................................ 15 

12. Discharge and chloride flux at presumed base-flow conditions measured on major streams in the 

Boundary Creek drainage ... ... . .. .. . . . . . . . .. . . . . . . . ........................... ... ... ..... . . . . . . . ......... ... . . . . . . .. . . . . . . . ... ........... .... .. . . . . . . 16 

13. Map showing locations of snow courses in southwestern Yellowstone National Park and vicinity..................... 17 

14-16. Plots of: 

14. Water equivalent of snow cores from six sites in southwestern Yellowstone National Park and vicinity.... 17 

15. Precipitation at two collection sites in Yellowstone National Park.............................................................. 18 

16. Discharge and instantaneous chloride flux at four sites in the Henrys Fork drainage.................................. 19 

TABLES 

1. Inventory of discharge, chloride concentration, and chloride flux for streams in southwestern Yellowstone 

National Park......................................................................................................................................................... 8 

2. Inventory of discharge, chloride concentration, and chloride flux for streams in the Island Park Geothermal 

Area, Idaho . . .......... ... . ..... . .. . . . . . . . .. . . . . . . . .. . . . . . ... . . . . . . . . .. . ... .. . .... . .. .. .. . . . . . . . ... ... .. . .. . . . . . . . ........................... ... . . . .. . .. . . . . . .... . . . . . . 8 

3. Calibration data comparing discharges calculated using velocity meters with discharges from standard weir 

rating tables . . . .. . . .. . . . .. .. .. .. . .. . . . . . . .. .. . .. .. . .. . . . . . . . .. . . .. .. . .. . . . .. . .. . . . . . . . . .. .. . .. . .... . . . . . . .. . . . . . . . .. . . . . . . . .. . .. . . .. .. . . . . . . . .. . . . . . . . . . .. . . . . . .. .. . . .. 11 

4. Data from monitoring sites in southwestern Yellowstone National Park............................................................. 12 

III 
IV CONTENTS 

METRIC CONVERSION FACTORS 

Multiply 

feet (ft) 

miles (mi) 

cubic feet per second ( cfs) 

By 

0.3048 

1.609 

0.02832 

To obtain 

meters 

kilometers 

cubic meters per second 
MONITORING OF THERMAL ACTIVITY IN 

SOUTHWESTERN YELLOWSTONE NATIONAL PARK 

AND VICINITY, 1980-1993 

By Irving Friedman, I Daniel R. Norton,l and Roderick A. Hutchinson2 

ABSTRACT 

Stream monitoring in Yellowstone National Park is 

being carried out to obtain baseline information on the natural variations in thermal activity against which to assess possible future impacts of geothermal, oil and gas, and other 

types of development adjacent to the Park and to relate these 

variations to seismic events and the possible movement of 

magma under the Park. The proximity of the Island Park 

Geothermal Area in Idaho and its possible future development places particular emphasis on investigation of the 

southwestern part of the Park. 

Continuous automated measurements of thermal flux 

from features in this remote section of the Park proved to be 

impractical because of the necessity of visiting the sites frequently to service the equipment. A practical protocol was 

developed requiring the instantaneous measurement of the 

flux in surface streams once a year during the winter baseflow regime. The installation of weirs and staff gauges on 

the thermal streams made it possible to collect data from this 

area during a one-day helicopter trip. 

The changes in discharge of thermal streams, which 

originate from hot springs, correlated with changes in discharge of the major rivers draining the Park and also with 

changes in precipitation over the Park. Because over 94 percent of the chloride in the rivers and streams in the Park is of 

geothermal origin, chloride flux can also be used as a measure of thermal flux. Annual values in both discharge and 

chloride flux at 10 of the 11 monitoring stations during base 

1

U.S. Geological Survey, Denver Federal Center, Denver, CO 

80225-0046. 

2

Yellowstone National Park, Mammoth, WY 82190. 

flow fluctuated as much as 90 percent over the 1986-93 

period. About 5 percent of the thermal water exits the Park 

along the western boundary into the Henrys Fork drainage in 

Idaho. Monitoring of the chloride flux in this water may be 

a sensitive indicator of the effects of development of energy 

resources adjacent to the western boundary of the Park in the 

Island Park area. 

INTRODUCTION 

Monitoring of thermal activity in Yellowstone National 

Park has been carried out since 1980 to obtain baseline information on the natural variations in activity against which to 

assess possible future impacts of geothermal, oil, gas, and 

other types of development adjacent to the Park. The data 

will also relate these variations in activity to seismic events 

and to the movement of magma under the Park. Because of 

the proximity of the Island Park Geothermal Area (lPG A) in 

Idaho (fig. 1) and the possibility of future development of its 

energy resources, this investigation concentrated on the 

southwestern portion of the Park. This area contains many 

small and medium-size thermal features that may respond to 

disturbance by development adjacent to the Park. Of interest 

to this study are streams issuing from the thermal features, 

which makes feasible the monitoring of chloride flux. 

Jones and others ( 1979) published results on the amount 

of discharge and chloride concentration of surface waters in 

the Falls River drainage within the Park, which were useful 

in developing our experimental program. Data on the 

Boundary Creek thermal areas were reported by Hutchinson 

(1980) and by Thompson and Hutchinson (1980). To orient 

our program in the IPGA, we used data by Whitehead (1978) 

on surface waters in the Upper Henrys Fork Basin. 
2 THERMAL ACTIVITY IN SOUTHWESTERN YELLOWSTONE NATIONAL PARK AND VICINITY 

44°15' 

~ ro 

"'C 

c 

::I 

0 

..c 

<( 

CD 

!!:: 

EXPLANATION 

GEOTHERMAL AREAS 

1. Monitor Creek 

2. Middle Boundary Creek 

3. Silver Scarf 

4. Crescent Ridge 

5. Three Rivers 

6. Mountain Ash 

0 1 2 4 MILES 

I I I I I I II I I 

1 2 3 4 KILOMETERS 

ISLAND PARK 

GEOTHERMAL AREA 

(IPGA) 

YELLOWSTONE 

)\.Upper Boundary Creek 

j thermal areas /n 

Three River 

Junction ~.....::c.-Q--o. 

NAJNAL 

PARK ~e,~ <o_!bc; 

Figure 1. The southwestern portion of Yellowstone National Park and the Island Park Geothennal Area. 

This is the first published report of a long-term monitoring study in this area, the conclusions of which reinforce 

the necessity for such long-term monitoring of streams 

containing thermally derived chloride. The report is 

divided into two sections; the first discusses monitoring of 

thermal features within the Park, and the second is concerned with monitoring of rivers and streams outside the 

Park boundary that we believe contain thermal waters 

heated by the Park magma system. 

STREAM MONITORING IN 

SOUTHWESTERN YELLOWSTONE 

NATIONAL PARK 

INITIAL INVESTIGATIONS 

Because the study area was remote and difficult to 

access, we initially attempted to utilize automated 

equipment to record stream flow, water temperature, and 
STREAM MONITORING IN SOUTHWESTERN YELLOWSTONE NATIONAL PARK 3 

Figure 2. Aerial photograph of the Boundary Creek area, Yellowstone National Park. Photo taken January 31, 1984.1ooking northwest. 

electrical conductivity and to store the data for later retrieval. 

We planned to service the monitoring sites three times a 

year. The initial site was established at the Monitor Creek 

Thermal Area (fig. 2) on a small stream draining a hot 

spring, identified in figure 3 as Weir 3. The data was 

recorded daily at noon and midnight by a Campbell Scientific Co. Micrologger (Model CE 21) and stored on a magnetic-tape cassette. Although the instrument was capable of 

running for nine months on internal dry cells, the site was 

visited several times a year to service the equipment and 

retrieve the cassette containing the data. The relative flow of 

the thermal stream was monitored by recording the depth of 

water in Weir 3, located about 100 meters downstream from 

the hot-spring source. For the first nine months, temperatures 

and electrical conductivity were measured at the weir. Afterwards, temperatures were also measured in the hot -spring 

orifice, which discharged at a temperature of about 80°C. 

Figure 4 shows the data from October 1, 1980, to June 

15, 1981. Cooling of the water in the stream due to snow 

melt was observed during April and early May, 1981. The 

low electrical conductivity and high water flow also 

reflected the input of snow melt during this period. During 

late May and June of 1981, the water flow remained high but 

the temperature and electrical conductivity increased. This 

was attributed to increased fl ow from the hot spring, offsetting a decreased contribution from snow melt. 

The success of this effort encouraged us to establish a 

second instrumented site on a thermal stream in the Silver 

Scarf Thermal Area (fig. 2), located about 3.5 miles from the 

first site. Shortly after the equipment was installed, a series 

of problems arose. First, the thermistors used to measure 

temperature and water level in both weirs failed after time 

periods that varied from 1 to 10 months. Efforts to protect 

these devices proved unsuccessful, due probably to the continuous exposure to elevated temperatures. Secondly, the 

remote location, which could be accessed by foot or horseback only four months of the year and by helicopter the 

remainder of the year, made it impractical to service the sites 

frequently enough to secure continuous records. 

As a result of these initial field experiments, we decided 

on a protocol of annual visits at a multitude of noninstrumented sites rather than continuous monitoring at a few 

instrumented sites. Each site was to be visited in the winter 

at the time of presumed base flow. 
4 THERMAL ACTIVITY IN SOUTHWESTERN YELLOWSTONE NATIONAL PARK AND VICINITY 

Figure 3. Aerial photograph of the Monitor Creek Thermal Area, Yellowstone National Park. Photo taken November 1, 1980, looking 

west and showing monitoring sites. 

SUBSEQUENT INVESTIGATIONS 

To determine the sites at which thermal fluids exit in the 

southwestern portion of the Park and adjacent areas, a survey 

was made of the chloride flux of streams originating in these 

areas. From a previous investigation (Norton and Friedman, 

1985), it was determined that at least 94 percent of the chloride present in rivers draining the Park is of geothermal origin and, therefore, chloride flux can be used to assess 

thermal flux, as was suggested by Fournier and others 

(1976). To determine chloride flux, it is necessary to measure simultaneously the stream discharge and chloride concentration. The chloride flux is the product of these values 

(Norton and Friedman, 1985). A discussion of the experimental details and analytical protocols is given in Norton 

and Friedman (1991). 

The locations of the sites inventoried are shown in figures 5 and 6, and the experimental data are given in tables 1 

and 2. We determined that about 55 percent of the chloride 

leaving the southwestern part of the Park leaves via the Falls 

River. The remaining 45 percent leaves in streams draining 

the west boundary of the Park that in tum drain into the Henrys Fork (river) (fig. 6). Of the chloride that exits the Park 

via the Falls River, 70 percent originates in the Pitchstone 

Plateau and the Three Rivers Thermal Area, and the remaining 30 percent originates in the Boundary Creek drainage. 

Inasmuch as the latter drainage is closest to the Park boundary and the source of possible negative impact on the Park, 

we concentrated our efforts in this area. 

As a result of this survey, we selected 11 sites for monitoring in the southwestern part of the Park. Of these, ten are 

located in the Boundary Creek drainage and one in the Robinson Creek drainage. Of the ten sites, seven are located near 

the source of small thermal streams, two on large tributaries 

of Boundary Creek and one on Boundary Creek itself. The 

small streams were judged to be sensitive indicators of environmental change, and their discharges were easily 

measured by small weirs. To minimize any environmental 

impact, the weirs were constructed of redwood with an 

attached stainless steel weir plate. Figure 7 shows two typical weirs. The discharges of the larger streams were measured using velocity meters. 
STREAM MONITORING IN SOUTHWESTERN YELLOWSTONE NATIONAL PARK 5 

50 

(/) 

::l 

w'U5 40 

cr:....J 

::>UJ 1-:u 

<((J) 

cr:.w 30 UJUJ 

a.. a:. ~(!) 

UJUJ 

t-0 20 

.!:: 

10 

500 

>= I- 400 

> i=(/) 

uo 

::li 300 ~~ oo 

ucr:. 

_J~ 

<(~ 200 

~ c:: a:.·-

Iu 

UJ 

_J 100 

UJ 

0 

6 

a:.' 5 

w 

s 

Z(J) 

- UJ 4 

II 

1-U 

a..z 

UJ0 c:: 3 

a:. 

UJ 

~ s 

OCTOBER NOVEMBER DECEMBER JANUARY FEBRUARY MARCH APRIL MAY JUNE 

1980 1981 

Figure 4. Physical data obtained using automated monitoring equipment at Weir 3, Monitor Creek Thermal 

Area, Yellowstone National Park. 

The thermal areas in which these streams are located 

were described by Hutchinson (1980) and are listed below 

and shown in figure 1: 

(1) Monitor Creek Thermal Area (fig. 3) is the southernmost of the Upper Boundary Creek thermal areas. The 

three sites being monitored constitute most of the surface flow from the thermal features at this locality: 

Weir 1. The flow into this weir issues from a small 

thermal area containing hot acid waters and steam 

vents tens of meters upstream. 

Weir 2. This is located on a small stream that appears to drain the large steam and acid-water vents 

that are the main visible features of the Monitor 

Creek Thermal Area. 

Weir 3. This weir is on a small thermal stream that 

drains a hot spring located about 50 meters upstream. Occasionally, a small fraction of the 

streamflow is from an intermittent cold-water 

source. 

(2) Middle Boundary Creek Thermal Area (fig. 8) was also 

described by Hutchinson (1980). The four sites monitored here constitute most of the surface flow from this 

geothermal feature. All four thermal streams are fed 

by springs that issue from beneath the adjacent Summit 

Lake rhyolite flow. 

(3) Crescent Ridge Thermal Area (one site) consists of 

a series of low-temperature (approximately 25°C) 

thermal springs that flow into an unnamed creek, 
6 THERMAL ACTIVITY IN SOUTHWESTERN YELLOWSTONE NATIONAL PARK AND VICINITY 

EXPLANATION 

Numbers refer to instantaneous 

flux values in grams per second. 

Letters refer to data in table 1 

~ Geothermal area 

0 1 I I I I I I 

1 2 

4 MILES 

I 

3 4 KILOMETERS 

ISLAND PARK 

GEOTHERMAL AREA 

(IPGA) 

YELLOWSTONE 

I 

------~---

> 

m 

"0 

c 

:::::1 

0 

.0 

<( 

(.!) 

9:: 

Figure 5. Map showing sites where chloride flux was measured in southwestern Yellowstone National Park and vicinity. 

referred to here as Crescent Ridge Creek. This 

stream flows into Little Robinson Creek, which 

flows into Robinson Creek. The latter is a tributary 

of Warm River, which in turn joins the Henrys 

Fork. Therefore, this thermal area is not in the 

Boundary Creek-Falls River drainage. 

In addition to the small thermal streams described 

above, three large streams, each of which integrate the discharge of a number of thermal features, were provided 

with staff gauges (calibrated using velocity meters) for 

the measurement of discharge. These streams are monitored as follows: 

(1) Silver Scarf Creek drains a large thermal area named 

by Hutchinson (1980) as the Silver Scarf Thermal 

Area. The staff gauge is located more than 20 meters 

downstream from the last thermal stream that enters 

the creek. 

(2) Boundary Creek Tributary was described by Jones 

and others (1979) as unnamed creek No. 1783. Our 

gauging site is located one-half mile upstream from 
STREAM MONITORING IN SOUTHWESTERN YELLOWSTONE NATIONAL PARK 7 

450 

00' 

EXPLANATION 

Instantaneous chloride flux 

in grams per second 

0 5 10 MILES 

t------~---.---'1 I 

20 KILOMETERS 

Figure 6. Map of the Henrys Fork drainage in the Island Park Geothermal Area, 

Idaho, showing instantaneous chloride flux at various springs and streams. Flux values are calculated from chloride and discharge data by Whitehead. (1978). 

the junction of the tributary with Boundary Creek 

and adjacent to the "Boundary Creek Patrol Cabin" 

site shown on the Warm River Butte 15' quadrangle 

map (1957 edition). The patrol cabin no longer exists and the site has been developed as a campground. 

(3) Boundary Creek, at a location where it integrates all 

of the thermal waters originating in the Boundary 

Creek Thermal Area. The staff gauge is upstream 

from the area in the Bechler Meadows that is flooded annually by overflow from the Bechler River. It 

is located about 100 meters south of the upper bridge 

where the Boundary Creek Trail crosses Boundary 

Creek. 
8 THERMAL ACTIVITY IN SOUTHWESTERN YELLOWSTONE NATIONAL PARK AND VICINITY 

Table 1. Inventory of discharge, chloride concentration, and chloride flux for streams in southwestern Yellowstone National Park. 

[Measurements made September 26-0ctober 3, 1985; ppm, parts per million; cfs, cubic feet per second; g/s, grams per second] 

Map Chloride Stream Chloride 

Site reference Location concentration disch. flux 

(fig. 5) (ppm) (cfs) (g/s) 

Boundary Cr. A Between Monitor and Mid. Boundary Cr. Th. Areas 4.8 25.8 3.5 

Boundary Cr. B Between Dunanda Falls and Silver Scarf Creek 12.6 34.5 12.3 

Boundary Cr. c Near confluence with Bechler River 15.7 122 54.2 

Silver Scarf Cr. D At gauging site below Silver Scarf Thermal Area 57.1 10.7 17.3 

Bechler River E Near confluence with Falls River 11.4 351 113 

Mt.AshCr. F Near confluence with Falls River 10.7 143 43.3 

Calf Cr. G Near confluence with Falls River 0.7 2.50 0.05 

Falls River H Below confluence with Mountain Ash Creek 6.3 160 28.4 

Falls River J Above confluence with Mountain Ash Creek 8.3 277 64.6 

Falls River K Above confluence with Calf Creek 6.0 140 23.4 

Falls River L At Squirrel, Idaho, gauging site 9.1 693 178 

Little Robinson Cr. M Near confluence with Robinson Creek 3.3 4.47 0.42 

Table2. Inventory of discharge, chloride concentration, and chloride flux for streams in the Island Park Geothermal Area adjacent 

to the southwestern boundary of Yellowstone National Park. 

[Chloride in parts per million; discharge in cubic feet per second; flux in grams per second;(-), no data] 

Site Property Oct.3 Sept. 17 Oct.8 Oct. 17 Oct.4 Sept.14 Oct. 17 Oct. 21 

1984 1985 1986 1988 1989 1990 1991 1992 

Big Springs Chloride 2.6 2.4 2.5 3.0 2.6 2.7 2.9 

Discharge 214 198 223 11.0 13.4 178 174 

Flux 15.8 13.5 15.8 13.4 13.7 13.6 14.3 

Buffalo River Chloride 3.8 3.5 2.3 2.9 2.3 2.2 2.7 

Discharge 237 235 184 191 215 209 181 

Flux 25.5 23.3 12.0 15.7 14.0 13.0 13.8 

Robinson Creek Chloride 6.8 6.9 7.7 7.5 7.1 8.1 8.0 7.9 

Discharge 123 108 65 62 80 59.9 63.2 53.8 

Flux 23.7 211 14.2 13.2 16.0 13.7 14.3 12.0 

Warm River Chloride 6.8 5.3 6.0 5.8 5.7 5.7 5.7 5.7 

Discharge 424 283 215 212 252 227 220 196 

Flux 81.6 42.5 36.5 34.8 40.7 35.6 35.5 31.6 
STREAM MONITORING IN SOUTHWESTERN YELLOWSTONE NATIONAL PARK 

Figure 7. Photographs of Weir 4 (top), located in the Middle Boundary Creek Thermal Area, and Weir 8 (bottom) in 

the Crescent Ridge Thermal Area, Yellowstone National Park. 

9 
10 THERMAL ACTIVITY IN SOUTHWESTERN YELLOWSTONE NATIONAL PARK AND VICINITY 

Figure 8. Aerial photograph of the Middle Boundary Creek Thermal Area, Yellowstone National Park, looking east and 

showing monitoring sites. 

CALIBRATION OF WEIRS AND 

STAFF GAUGES 

Calibration of the discharges through weirs is often 

made using velocity meters. For these small shallow streams 

with irregular bottoms, the measurements of discharge by 

stream velocity are considered to be less accurate than those 

made using standard weirs. Despite this, the results in table 

3 show reasonable agreement between measured flows and 

those derived from the standard rating tables (Larsen, 1976) 

for weirs. 

The discharges of the large streams where staff 

gauges were located were measured using velocity 

meters and standard hydrologic methods. When sufficient data have been accumulated, rating tables for these 

gauging sites will be prepared. 

RESULTS 

The results of the discharge measurements, the chloride 

concentrations, and the calculated chloride flux are given in 

table 4 and plotted in figures 9-I2. For monitoring purposes, 

we have chosen to consider only the flux measurements 

made during the winter at presumed base flow. However, for 

future reference we also listed data from measurements 

made at other times of the year. 

Data for the Monitor Creek weirs are plotted in figure 

9. The stream at Weir I showed a fairly constant chloride 

concentration but a variable flow rate that actually dropped 

to zero during February and March of I989, I992, and I993. 

The discharge and chloride content of Weir 2 fluctuated 

greatly for reasons that are not apparent. The results for 

Weir 3 resembled those for Weir I. 

Figure IO contains similar plots of the data for Weirs 

4-7located in the Middle Boundary Creek Thermal Area. In 

general, the results show a decrease in discharge and chloride flux at all sites from late I983 to March I993, with the 

major portion of the decline occurring after I986. 

The results for Weir 8, located in the Crescent Ridge 

Thermal Area (fig. 2), are plotted in figure II. The stream 

was not flowing in March, 1993. These results also display 

the large changes seen in the other thermal areas. 
STREAM MONITORING IN SOUTHWESTERN YELLOWSTONE NATIONAL PARK 11 

Table3. Calibration data comparing discharges measured in weirs using velocity meters and discharges from standard weir rating tables. 

[Calibrations made by four different individuals from September 1987 to March 1991. T, values from standard weir rating tables of water height versus discharge (Larson, 1976); 

M, values calculated using velocity meters; cfs, cubic feet per second; ND, no discharge; (-), no data; ( --), not applicable] 

Weir 

Thermal 

area No. Type Width Sept. 9, 1987 Feb. 17, 1988 

(ft) T M T M 

Monitor Cipoletti 0.75 0.15 0.16 0.028 0.035 

Creek 2 goo V-Notch 0.002 0.002 ND ND 

3 90° V-Notch 0.05 0.08 ND ND 

Middle 4 Cipoletti 1.0 0.26 0.33 0.26 0.18 

Boundary 5 goo V-Notch 0.13 0.14 

6 Cipoletti 1.0 0.23 0.24 0.23 

7 Cipoletti 1.0 0.38 0.32 0.23 

Crescent 8 Cipoletti 2.0 0.36 0.37 

Ridge 

The data for the three large streams in the Boundary 

Creek drainage are plotted in figure 12. Boundary Creek and 

Silver Scarf Creek show large decreases in discharge and 

chloride flux after 1986. The monitoring of Boundary Creek 

Tributary started in February 1987, with no earlier data 

available for comparison. 

The large decreases in discharge observed in both the 

small and large thermal streams can be attributed to a lowering of the water table resulting from several years of exceptionally low precipitation. The reductions in discharge of the 

springs parallel the observed changes in discharge of the 

major rivers draining the Park (Falls, Madison, Snake, and 

Yellowstone Rivers), which also show large decreases in 

1987 and 1988 followed by a small increase in 1989 (Norton 

and Friedman, 1991). 

A plot of the water-equivalent of the snow pack collected on April1 (the date of maximum snow pack) from six 

sites in the southwestern area of the Park (locations shown in 

figure 13) for 1980-92 is shown in figure 14. The changes in 

discharge of the monitored thermal springs and rivers draining these features (table 4) tend to follow the changes in the 

water content of the winter snow, which is the major source 

of recharge of the aquifers in this region. A plot of the total 

precipitation received at Snake River (south entrance of the 

Park) and Yellowstone Lake during the same period is 

shown in figure 15. This diagram also shows a good correlation between thermal-spring discharge and precipitation. 

The decrease in precipitation during 1987 and 1988 is 

Discharge (cfs) 

Feb.25, 1989 Mar. 25, 1991 Mar. 12, 1992 Mar. 12, 1993 

T M T M T M T M 

ND ND ND ND ND ND ND ND 

0.026 0.02 0.023 0.026 0.081 0.037 0.031 0.013 

ND ND ND ND 0.006 0.007 ND ND 

0.23 0.17 0.25 0.28 0.25 0.33 0.25 0.32 

0.14 0.11 0.14 0.09 0.081 0.082 0.07 0.13 

0.18 0.17 0.16 0.25 0.23 0.25 0.18 0.17 

0.20 0.20 0.32 0.46 0.22 0.27 0.16 0.27 

0.10 0.15 ND ND 

mirrored by the decrease in spring discharge during these 

two years. Weirs 1, 2, and 7 also show an increase in flow in 

1989 and 1990 that correlates with increased precipitation 

and snow fall in 1988-89 and 1989-90 recorded at Snake 

River and Yellowstone Lake. 

The chloride concentration of the monitored springs is 

relatively constant through time, although their discharge 

varies both seasonally and over longer time periods. As a 

result, the chloride flux from these springs increases during 

periods of increased discharge. Friedman and Norton (1990) 

concluded that these changes were caused by changes in the 

height of the local water table, which affected the discharge 

of the springs but not their chloride concentration. These 

large variations in flow and chloride flux during this fiveyear period demonstrate the need for long-term monitoring 

to secure meaningful baseline data and to relate changes in 

hot-spring activity to other natural phenomena. 

CONCLUSIONS 

Based on the experience gained and on the data accumulated in this part of the study, the following conclusions 

are drawn: 

(1) Continuous instrumental measurement of thermal flux 

from features in the southwestern portion of Yellowstone National Park is impractical because of the 

remoteness of the area and the necessity of visiting the 
...... 

N 

Table4. Stream discharge, chloride concentration, and chloride flux data from monitoring sites in southwestern Yellowstone National Park. 

[Chloride in parts per million; discharge in cubic feet per second; flux in grams per second;(-), no data; base-flow (winter) measurements in bold type] 

:d 

ttl 

1983 1984 1986 1987 1987 1987 1987 1988 1989 1990 1990 1990 1991 1991 1991 1992 1993 ~ Site Property Nov. Jan. Sept. F«h Aug. Sept. Sept. Fro. F«h Mar. June Sept. Mar. June Sept. Mar. Mar. > 

9 31 7 5 24 9 25 10 1 15 23 26 28 20 11 12 12 r 

f) 

Weir 1 Chloride 1.5 1.7 0.9 1.3 - 1.1 - 2.6 - 2.3 1.7 1.9 2.0 1.8 1.0 - - ~ 

Discharge 0.52 0.33 0.4 0.21 0.18 0.15 0.13 0.06 no flow 0.052 0.47 0.18 0.028 0.486 0.15 no flow no flow -

< 

Flux 0.022 0.016 0.010 0.0077 - 0.00047 - 0.0044 - 0.0033 0.022 0.010 0.0016 0.025 0.0041 - - ~ 

~ 

Weir2 Chloride 26.0 4.0 24.7 1.4 - 0.2 - 0.3 0.3 1.3 32.5 1.6 1.3 8.3 1.0 0.3 0.50 -

z 

Discharge 0.093 0.030 0.055 0.030 0.005 0.002 0.001 0.04 0.026 0.026 0.008 0.005 0.023 0.009 0.029 0.016 0.013 en Flux 0.069 0.0034 0.038 0.0012 - 0.000001 - 0.0004 0.0002 0.0009 0.0074 0.0002 0.0008 0.0021 0.0082 0.00014 0.0002 0 

Weir3 Chloride 5.9 7.6 6.5 9.7 - 12.7 - 16.6 - 9.3 13.9 14.2 3.3 15.6 15.4 3.2 - Discharge 

Flux 0.016 

0.093 

0.030 

0.138 

0.020 

0.11 

0.021 

0.075 0.054 

- 0.049 0.018 

0.045 

- 0.04 

0.019 

no 

-

flow 0.005 

0.0013 

0.038 

0.015 

0.023 

0.0092 

0.001 

0.0001 

0.051 

0.023 

0.062 

0.027 

0.006 

0.0005 

no 

-

flow ~ ttl 

en 

Weir4 Chloride 63.7 65.5 64.2 66.7 - 71.3 - 65.6 68.9 63.0 63.1 68.5 62.9 45.0 71.9 69.9 71.0 trl 

Discharge 0.37 0.35 0.33 0.34 0.28 0.26 0.27 0.26 0.23 0.26 0.25 0.27 0.25 0.26 0.25 0.25 0.25 ~ 

z Flux 0.67 0.65 0.60 0.64 - 0.53 - 0.48 0.45 Cl46 0.45 0.52 0.45 0.33 0.51 0.49 0.50 ~ 

ttl 

WeirS Chloride 57.2 58.7 59.9 - - 67.1 - 58.3 58.3 55.4 1.0 - 55.3 46.6 69.6 60.5 63.6 r 

Discharge 0.24 0.25 0.22 - - 0.11 - 0.13 0.14 0.14 4.52 - 0.14 0.17 0.057 0.15 0.13 r 

Flux 0.39 0.42 0.37 - - 0.21 - 0.22 0.23 0.22 0.13 - 0.22 0.22 0.11 0.26 0.23 ~ en Weir6 Chloride 64.3 65.9 68.8 68.3 - 73.3 - 63.7 62.8 60.8 44.9 65.9 60.4 62.4 71.1 64.6 65.6 

Discharge 0.53 0.84 0.34 0.35 0.18 0.23 0.23 0.23 0.18 0.20 0.34 0.21 0.16 0.25 0.20 0.24 0.18 ~ Flux 0.97 1.57 0.66 0.68 - 0.48 - 0.42 0.32 0.35 0.43 0.39 0.27 0.44 0.41 0.44 0.33 ttl 

Weir 7 Chloride 75.0 76.9 80.0 78.5 - 86.6 - 77.9 76.7 72.2 70.7 76.3 69.6 66.6 82.6 78.1 78.1 ~ Discharge 0.83 0.61 0.56 0.58 0.40 0.38 0.36 0.23 0.20 0.30 0.40 0.32 0.32 0.34 0.26 0.22 0.16 :j 

Flux 1.76 1.33 1.27 1.29 - 0.93 - 0.51 OA3 0.61 0.80 0.69 0.63 0.63 0.62 0.49 0.35 0 

z 

WeirS Chloride - 4.8 4.1 3.5 - 5.0 - - 3.9 4.9 5.0 5.6 4.5 5.1 - 3.6 > - r 

Discharge - 0.97 2.0 0.50 - 0.36 - - 0.096 0.10 1.72 0.72 0.057 1.14 - 0.10 no flow ., 

> Flux - 0.13 0.23 0.050 - 0.051 - - 0.011 0.014 0.24 0.12 0.007 0.16 - 0.010 - ~ 

~ 

Silver Chloride - 66.7 56.7 72.5 - 83.6 - 83.4 87.4 76.4 69.4 74.8 78.7 73.1 84.2 86.2 90.8 

Scarf ~ Discharge - 9.35 8.60 8.()7 6.80 5.54 5.54 4.81 4.64 5.22 7.20 - 5.51 - 4.82 4.80 4.o7 

Creek Flux - 17.7 13.8 17.8 - 13.1 - 11.4 11.5 11.3 14.1 - 12.3 - 13.9 11.7 10.5 

< 

Boundary Chloride - 16.9 17.1 22.6 - 19.7 - 19.5 19.5 19.9 11.4 - 19.2 - 18.9 18.9 22.2 -(') 

Creek Discharge - 83.3 93.6 78.6 - 65.7 - 50.9 57.7 60.5 98.3 - 57.2 - 71.1 60.4 47.4 -

z 

Flux - 39.9 45.3 50.3 - 36.7 - 28.7 31.9 34.1 31.8 - 31.0 - 38.1 32.3 29.8 

~ Boundary Chloride - - - 6.5 - 6.0 - 6.3 6.2 6.4 6.1 - 6.7 - 5.6 5.9 7.2 

Creek Discharge - - - 31.6 - 32.0 - 29.6 32.8 36.1 33.3 - 35.5 - 34.3 31.2 27.8 

Tributary Flux - - - 5.83 - 5.42 - 5.28 5.71 6.53 5.75 - 6.78 - 5.44 5.21 5.67 
STREAM MONITORING IN SOUTHWESTERN YELLOWSTONE NATIONAL PARK 13 

0.4 0.020 

Weir 1 

-- 0.3 --- 0.015 

- - ' ' 0.2 ·q 0.010 

EXPLANATION 

0 0.1 0.005 0 z Discharge z 

0 Flux 0 () 0 w 0.0 0.000 w 

(j) C/) 

a: 0.050 0.004 0: 

w Weir2 w 

a.. a.. 

r- 0.040 ,Q C/) w 0.003 I 

w , 2 

LL <X: 0.030 0--------- -----------o' 0: 

() b-------{)-''''' "0, 0.002 ~ 

co 0.020 ::J ' ' -~ ' 0 EXPLANATION 'o,, X~ '"() 0.001 :J -~ 0.010 -----o---- Discharge _J 

w • Flux LL 

~ 0.000 0.000 w 

0: 0 

<{ 0.20 0.04 a: I 0 0 _J 

C/) Weir3 I 

0 0.15 0.03 0 

- 0.10 -' 0.02 

0.05 EXPLANATION 

0.01 

-----{)---- Discharge 

Flux 

0.00 0.00 

1984 1986 1988 1990 1992 

YEAR 

Figure 9. Plots of discharge and chloride flux at presumed base-flow conditions for weirs located in the 

Monitor Creek Thermal Area, Yellowstone National Park. 

sites frequently to service the equipment. These visits 

would be prohibitively expensive because access for 

eight months of the year is limited to helicopter flights, 

and the nearest available helicopter service is in Jackson, Wyo., a distance of 75 miles from the study area. 

(2) A practical protocol for monitoring thermal flux in this 

region of the Park is the measurement, once a year, of 

the instantaneous chloride flux from a number of 

surface thermal features during base flow. The 

installation of weirs on most of the thermal streams in 

the Boundary Creek area has made it possible to collect 

the necessary data during the winter by a one-day helicopter trip. 

(3) The observed reductions in both discharge and chloride flux at the monitoring stations were as great as 90 

percent during the 1986-92 period. These large 
14 1HERMAL ACTIVITY IN SOUTHWESTERN YELLOWSTONE NATIONAL PARK AND VICINITY 

0.4 

0.3 

0.2 

0.1 

0.0 

0.3 

0 

z 

0 0 0.2 

w 

Cf) 

a: 0.1 

w 

a.. 

r- 0.0 

w 

w 

LL 

0 1.0 

co 

:::> 0.8 

0 

c 0.6 

w 0.4 

(9 

a: 0.2 

<( 

25 o.o 

(/) 

0 

0.7 

0.6 

0.5 

0.4 

0.3 

0.2 

0.1 

0.0 

o------------------a .... , Weir 4 

• ,----o.__ _.-0-----.o----- o------o ~-o··· 

EXPLANATION • • •____. • 

----<>---- Discharge 

• Flux 

1984 1986 1988 1990 1992 

0, ... 

--- WeirS -... , -... -... 

EXPLANATION 

---- <>- --- Discharge 

• Flux 

1984 1986 1988 1990 1992 

Weir6 

1984 1986 1988 1990 1992 

-------- Weir 7 

EXPLANATION 

-----o---- Discharge 

• Flux 

1984 1986 1988 1990 1992 

YEAR 

0.8 

0.6 

0.4 

0.2 

0.0 

0.6 

0.5 

0.4 

0.3 

0.2 

0.1 

0.0 

2.0 

1.5 

1.0 

0.5 

0.0 

1.6 

1.4 

1.2 

1.0 

0.8 

0.6 

0.4 

0.2 

0.0 

0 

z 

0 

0 

w 

(/) 

a: 

w 

a.. 

(/) 

~ 

~ (9 

c 

X~ 

:::> 

.....J 

LL 

w 

0 

a: 

g 

I 

0 

Figure 10. Plots of discharge and chloride flux at presumed base-flow conditions for weirs located in the 

Middle Boundary Creek Thermal Area, Yellowstone National Park. 
MEASUREMENT OF THERMALLY DERIVED CHLORIDE IN THE ISLAND PARK GEOTHERMAL AREA, IDAHO 15 

0 0 z 1.0 0.15 z 0 0 0 ' ' Weir 8 w 0 

w (j) ' (j) 

a: 0.8 ' a: w ' EXPLANATION w 0... 

' 0... 

I- ' ' 0.10 (j) w 

w ~ 0.6 ----0---- Discharge LL ' ' <!: 

0 ' ' a: 

03 o_ • Flux C) 

::> c ' 0 0.4 \ X- c 0.05 ::> 

....J 

w ' LL 

C) \ w 

a: 0.2 \ 0 

<( \ 

a: I 0 0 ....J (j) 

0.00 I 

0 0.0 0 

1984 1986 1988 1990 1992 

YEAR 

Figure 11. Plot of discharge and chloride flux at presumed base-flow conditions for Weir 8,located in the 

Crescent Ridge Thermal Area, Yellowstone National Park. 

changes demonstrate the necessity for long-term monitoring to establish a baseline for assessing possible 

future effects of development west of the Park boundary, which includes extraction of gas and oil as well 

as geothermal water and steam. 

(4) The discharge of the systems that we monitored appears to respond to the availability of meteoric water. 

A surprising discovery is the direct relationship between discharge of the thermal systems and chloride 

flux. Whether this relationship is the result of chloride 

storage during low-flow regimes and release of stored 

chloride during periods of high discharge, or whether 

it is the result of the direct influence of water-table 

height on the hydrothermal system, has been a subject 

of controversy. Our evidence, based on studies of hot 

springs where storage cannot have occurred, substantiates the latter explanation. 

MEASUREMENT OF THERMALLY 

DERIVED CHLORIDE IN THE ISLAND 

PARK GEOTHERMAL AREA, IDAHO 

Monitoring of thermal waters exiting the Park into the 

IPGA west of the Park should provide early warning of the 

adverse effects of development in this area of geothermal, 

gas, and oil resources. From an examination of published 

hydrologic records, Norton and Friedman (1985) concluded 

that about 5 percent of thermal water exiting the Park 

emerges in the IPGA, adjacent to the west boundary of the 

Park, as surface and subsurface flow. This water ultimately 

flows into the Henrys Fork. 

Taking the December 5, 1974, data from Whitehead 

(1978) for discharge and chloride concentration at selected 

sites, we calculated instantaneous chloride flux for the sites 

along, and tributary to, the Henrys Fork. These values are 

shown in figure 6. About 70 percent of the chloride flux exiting the IPGA at Ashton, Idaho, is accounted for by the sum 

of the chloride flux from Big Springs, Buffalo River, Warm 

River, and Robinson Creek. Another 20 percent is from subsurface inflow to the Henrys Fork between Osborne Bridge 

and Warm River. About 3 percent is from inflow between 

Henrys Lake and Big Springs, and most of the remaining 7 

percent is from the Island Park Reservoir. 

Our data for 1984--92, shown in table 2 and plotted in 

figure 16, depicts discharge and chloride flux in Big 

Springs, Buffalo River, Warm River, and Robinson Creek. 

All of the streams suffered a decline in discharge and chloride flux with time. The change in the chloride flux in Big 

Springs is significantly less than the changes in the other 

three streams. The discharge of Big Springs, Robinson 

Creek, and Warm River also decreased after the 1985-86 

period. These changes follow similar trends in the data 

from the major rivers draining the Park, as reported in 

Norton and Friedman (1991). Similar trends appear in the 

data that we report for the thermal streams inside the southwestern portion of the Park. 
16 THERMAL ACTIVITY IN SOUTHWESTERN YELLOWSTONE NATIONAL PARK AND VICINITY 

100 60 

Boundary Creek 

50 

75 

40 

50 30 

EXPLANATION 20 

25 -----o---- Discharge 

• Flux 10 

0 0 0 0 z 1984 1986 1988 1990 1992 z 0 0 0 

w 0 

50 8 w (/) (/) 

a: Boundary Creek Tributary 7 a: 

w 40 w a_ 6 0... 

1- 5 (/) w 30 ,, 

w ''~~o ~ 

LL 4 <( 

a: 

0 20 3 (.9 

(]) EXPLANATION 

c 

:::J -----o---- Discharge 2 

0 10 

• Flux X 

c :::J 

_j 

w- 0 0 LL 

(.9 1984 1986 1988 1990 1992 w 

a: 0 

~ 25 a: 

I 12 0 0 _j 

(/) 10 I 

0 0------------------ 20 0 

8 

15 \ 

\ 

6 

4 EXPLANATION 

0------o------ ,,_ -'() 

10 

-----o---- Discharge 5 2 • Flux 

0 0 

1984 1986 1988 1990 1992 

YEAR 

Figure 12. Plots of discharge and chloride flux at presumed base-flow conditions measured at staff gauges on major streams in the Boundary Creek drainage, Yellowstone National Park. 
45° 

MEASUREMENT OF THERMALLY DERIVED CHLORIDE IN THE ISLAND PARK GEOTHERMAL AREA, IDAHO 17 

110° 

MONTANA _________ _....,') 

__ Ye!/0 ;s-c--··--·----Q; -~---

Or,. S ~ '9::-t- \ 

r]:}~:>G'"'"' J S I 

) 

I 

'\, 

\... 

/ 

_,.,.-:::J 

/"-..Park 

\ boundary 

\/''........., Yellowstone ./1 

Lake , 

I 

........... , 

I 

10 20 MILES 

I I I I 

10 20 KILOMETERS 

I 

CONCLUSIONS 

The large variations in chloride flux shown in these data 

support the conclusion that long-term monitoring is necessary along the Henrys Fork and its tributaries. The large thermal-water input to the Henrys Fork between Osborne Bridge 

and the confluence with Wann River can be monitored by 

taking the difference between measurements made at these 

two sites. We propose that a special effort be made to monitor chloride flux at the following locations during winter 

base flow: 

1. Henrys Fork at Macks Inn, above the confluence with 

Big Springs. 

2. Big Springs at Big Springs, or before the confluence of 

Big Springs with the Henrys Fork. 

3. Henrys Fork at the entrance to the Island Park reservoir. 

4. Henrys Fork at the exit of the Island Park reservoir. 

5. Buffalo River at the confluence with the Henrys Fork. 

6. Henrys Fork at Osborne Bridge. 

7. Henrys Fork above the confluence with Warm River. 

8. Warm River at the confluence with the Henrys Fork. 

9. Robinson Creek at the confluence with Wann River. 

Figure 13. Locations of U.S. Department of Agriculture Soil 

Conservation Service snow courses in southwestern Yellowstone 

National Park and vicinity. Dark line denotes the Continental 

Divide. 

Inasmuch as 90 percent of the chloride flux can be 

accounted for by monitoring locations 2 and 5-9, we suggest 

that priority be placed on these. For a complete evaluation 

of chloride input and output to the Henrys Fork river basin, 

the remaining three locations should be added. 

80 

EXPLANATION 

70 ---o-- Aster Creek ·········O········ Grassy Lake 

(f) -·-·iH-·-· Black Bear -- "*-- Lewis Lake Divide 

w 

I 60 ----+---- Coulter Creek -----6---- Snake River 

0 

z 

c 50 

~---

z 

w 40 __J 

<l:: 

> 

:::::> 30 

a 

w 

cr:: 

w 20 

I-

<l:: 

3: 1 0 

0 

1983 1985 1987 1989 1991 1993 

YEAR 

Figure 14. Plots of water equivalent of snow cores from six snow courses in southwestern Yellowstone National 

Park and vicinity (sites shown in fig. 13). The cores were collected each April 1, during maximum snowpack. Data 

from the Centralized Database System of the Soil Conservation Service, West National Technical Center, Portland, 

Ore. 
18 TIIERMAL ACTIVITY IN SOUTIIWESTERN YELLOWSTONE NATIONAL PARK AND VICINITY 

(f) 

w 

I 

0 

z 

40 

30 

.5 

z 

0 

,/\, A I \ 

.. •••··•··· ···....... ;' \ 

0 

.. ·· •·· ................... 0··········-d· '\... p. .• o. ..... . ..., / ··..... ..... ····-o 

o. ' ······a······· 

20 

~ 1-

a:: 

0 

w 

c: 

a.. 

1 0 

0 

EXPLANATION 

---a- Snake River 

........ -o........ Yellowstone Lake 

1981 1983 1985 

·····........ /,/ 

·· ...... · ''d 

1987 1989 1991 1993 

YEAR 

Figure 15. Plots of total yearly precipitation at two collection sites in Yellowstone National Park. Data from the 

National Oceanic and Atmospheric Administration's National Environmental Satellite, Data, and Information Service, 

National Climatic Data Center, Asheville, N.C. 

ACKNOWLEDGMENTS 

Within the U.S. Geological Survey, we are indebted to 

Robert W. Harper of the Idaho District, Water Resources 

Division, for his support and encouragement. The field 

office of this district, under the supervision of Nathan D. 

Jacobson, was responsible for stream discharge measurements beginning in 1982 and continuing throughout 1993. 

Under his direction, the following persons contributed to our 

field work in the Park utilizing backpacking, skis, horses, 

and helicopters to access these remote areas: Robert W. 

Erickson, Owen E. McLaughlin, Stephen J. Wegner, Brian 

D. Higgs, Stanley G. Landon, and Jay Bateman. 

Also within the Water Resources Division, we are 

indebted to Harold D. Ardourel of the National Water Quality Laboratory for his supervision of the chloride analyses 

required for this study. Under his direction, the following 

persons contributed to the laboratory work: Diane Wisniewski, Betty McLain, Carl M. Harris, and Gary L. Cottrell. 

We wish to thank Augusta Warden of the Geologic Division 

for her work on the distribution of sampling kits and the sample control required for this project. 

We also wish to acknowledge John D. Varley, Chief of 

Research, Yellowstone National Park, for his continued 

interest and support of this work. 

REFERENCES CITED 

Fournier, R.O., White, D.E., and Truesdell, A. H., 1976, Convective 

heat flow in Yellowstone National Park, in Proceedings of the 

United Nations symposium on the development and use of 

geothermal resources, San Francisco, 1975: Washington, D.C., 

U.S. Government Printing Office, v. 1, p. 731-739. 

Friedman, Irving, and Norton, D.R., 1990, Anomalous chloride 

flux discharges from Yellowstone National Park: Journal of 

Volcanology and Geothermal Research, v. 42, p. 225-234. 

Hutchinson, R.A., 1980, Boundary Creek thermal areas of Yellowstone National Park, 1-Thermal activity and geologic setting: 

Geothermal Resources Council Transactions, v. 4, p.129-132. 

Jones, R.D., Gresswell, R.E., Jennings, D.E., Lentz, D.C., Rubrecht, S.M., VanDeventer, J.S., and Varley, J.D., 1979, 

Hydrographic surveys of the Falls River drainage-Fishery 

and aquatic management program in Yellowstone National 

Park: U.S. Fish and Wildlife Service, Technical Report for Calendar Year 1978, p. 167-184. 

Larsen, D.C., 1976, Water measurement: University ofldaho, College of Agriculture, Cooperative Extension Service 

Bulletin 552. 

Norton, D.R., and Friedman, Irving, 1985, Chloride flux out of Yellowstone National Park: Journal of Volcanology and Geothermal Research, v. 26, p. 231-250. 
REFERENCES CITED 

300 20 

~- Big Springs 15 

200 • • . ____. '-o- ----------· ---0. ·-. • • -o- •• --.- •••• -• -- <>- ------o 10 

EXPLANATION 

100 -----o---- 5 

0 0 0 0 z z 0 300 30 0 0 

~----·. ~ .. -~-~~~~-~~:r_ .... ····--.- <>- w 0 (f) w 

200 20 Cf) 

a: ·-o------· ·····-o 

w a: 

EXPLANATION • • -4 w 0.. 

I- 100 -----o-- -- Discharge 10 0... 

w Flux (f) 

w ~ LL 0 0 <I: 

0 a: 

co 150 25 <.9 

=> c 

(.) ·-- 20 

'•-o, ><~ 

c. 100 

15 => 

uj ',__ _ _____ . .o ___ ...J 

EXPLANATION 'o-------- LL 

<.9 .. o--------------. -o---... ·o 10 w 0:: 50 -----0··-- Discharge 0 <I: Flux 5 a: I 

(.) 0 0 0 

Cf) _J 

I 0 500 90 (.) 

400 EXPLANATION 

-----o---· Discharge 60 

300 • Flux 

200 

30 

100 

0 0 

1984 1986 1988 1990 1992 

YEAR 

Figure 16. Plots showing discharge and instantaneous chloride flux at four sites in the Henrys Fork drainage, Island Park Geothermal Area, Idaho. 

19 

Norton, D.R., and Friedman, Irving, 1991, Chloride flux and surface water discharge out of Yellowstone National Park, 

1982-1989: U.S. Geological Survey Bulletin 1959, 42 p. 

activity and geologic setting: Geothermal Resources Council 

Transactions, v. 4, p. 189-192. 

Thompson, J.M., and Hutchinson, R.A., 1980, Boundary Creek 

thermal areas of Yellowstone National Park, II-Thermal 

Published in the Central Region, Denver, Colorado 

Manuscript approved for publication July 21, 1993 

Graphics prepared by Norma J. Maes 

Photocomposition by Shelly Fields 

Edited by John Synnefakis 

Whitehead, R.L., 1978, Water resources of the Upper Henrys Fork 

Basin in eastern Idaho: Idaho Department of Water Resources, 

Water Information Bulletin No. 46, 89 p. 

*U.S. ~ PRIN'l'IRi OFFICE: 1994-573-038/86021