M ONTANA

WYO MI NG

M ONTANA

WYO MI NG

Powder River

Structural

Basin

U.S. Department of the Interior

U.S. Geological Survey

Fact Sheet 2006-3047

March 2006

Data Collection for the Assessment of Aquatic Communities 

in Northeastern Wyoming and Southeastern Montana, 2005

Printed on recycled paper

Introduction

This fact sheet describes data collection for the assessment 

of aquatic communities in northeastern Wyoming and southeastern Montana. This assessment was conducted in 2005 in cooperation with the Bureau of Land Management (BLM), Montana 

Department of Environmental Quality (MDEQ), Montana Fish, 

Wildlife and Parks (MFWP), U.S. Environmental Protection 

Agency (USEPA), Wyoming Department of Environmental 

Quality (WDEQ), and Wyoming Game and Fish Department 

(WGFD). This fact sheet also describes groups with interests or 

responsibilities in monitoring the effects of coal-bed natural gas 

development within the Powder River Basin.

The Powder River Structural Basin (PRB) in northeastern 

Wyoming and southeastern Montana is an important source of 

energy resources for the United States. Resources produced 

from the basin include coal, oil, uranium, conventional natural 

gas, and within the last decade coal-bed natural gas (CBNG) 

that often is referred to as coal-bed methane. As of 2004, more 

than 10,000 CBNG wells had been drilled in northeastern Wyoming (Wyoming Oil and Gas Conservation Commission, 2005). 

An estimated 50,000 to 60,000 CBNG wells could be drilled 

and put into production in the PRB by 2012 (Wyoming Oil and 

Gas Conservation Commission, 2005). Throughout the PRB 

large volumes of ground water are removed from coal-bed aquifers and discharged on the surface in order to recover CBNG. 

This ground water, which can be slightly to moderately saline, 

is discharged to perennial, intermittent, and ephemeral streams 

and to surface impoundments. It is currently unknown what 

potential effects these discharges will have on aquatic communities (fish, macroinvertebrates, and algae) and their habitats.

Powder River Natural Gas Interagency Working 

Group

Over a million acres within the PRB are public lands 

managed by the BLM. Development of mineral resources on 

public lands requires leases and permits from the BLM along 

with permits, approvals, and reviews by several other Federal 

and State agencies. CBNG development in the PRB is affecting 

agencies involved in permitting and monitoring in two States 

and two Tribes. To enhance coordination among interested 

agencies and reduce duplication of effort, the BLM organized 

the Powder River Natural Gas Interagency Working Group 

(PRB IWG). The PRB IWG charter states that it “was established as the forum for government agencies to address, discuss, 

and find solutions to issues of common concern to all parties 

involved in permitting and monitoring of CBNG development”

(Powder River Natural Gas Interagency Working Group, 2004). 

Led by the BLM, the PRB IWG is composed of managers and 

technical staff from local, State, Tribal, and Federal government 

agencies with land management, conservation, or regulatory 

responsibilities in the PRB, as well as agencies like the U.S. 

Geological Survey (USGS) that provide technical support.

The vision of the PRB IWG is to provide for development of natural gas resources while protecting the cultural and 

natural resources of the PRB. The mission of the PRB IWG is 

to (1) provide for environmentally sound energy development, 

(2) develop coordinated and complementary best management 

practices, guidelines, and programs related to CBNG activities 

to conserve and protect resources, (3) monitor the impact of 

CBNG activities and assess the effectiveness of mitigating measures, (4) develop and integrate databases and scientific studies 

needed for effective resource management and planning, and 

(5) promote compatibility in the application of each agency’s 

mission.

In order to effectively address the technical issues presented by CBNG development, task groups that are staffed by 

technical specialists from the member agencies of the PRB IWG 

were formed to address specific resource issues (Clark and 

others, 2005). The task groups include air, aquatics, water, and 

wildlife.
Figure 1.  Sampling sites for aquatic communities in northeastern Wyoming and southeastern Montana.

Yellowstone

CAMPBELL

JOHNSON

CARTER

CUSTER

CROOK

ROSEBUD

TREASURE

WESTON

POWDER RIVER

BIG HORN

SHERIDAN

NATRONA

CONVERSE

NIOBRARA

WASHAKIE

BIG

HORN

FALLON

 Tongue

 River Res

Lake

 De 

 Smet

Tongue

Pumpkin

Creek 

Otter Creek

Powder

Belle

Fourche

River

River

River

River

Creek

Creek 

Clear

Woman

Cra zy

River

Little

Missouri

River

River

Creek

Porcupine

Cheyenne

Cr

Creek

Hanging Woman

Powder

Little

River

Pow

der

Black Thunder Cr

Caballo Creek

Squirrel Cr

Youngs Cr

25

16

90

90

90

94

94

59

59

50

450

192

59

7

39

16

14

14

14

12

212

212

85

107° 106° 105°

44°

45°

46°

Base modified from U.S. Geological Survey digital data, 2001-03

Roads modified from Federal Highway Administration digital data, 2002

Albers Equal-area Conic projection

0 20 40 MILES

0 20 40 KILOMETERS Standard parallels 40° and 60°, central meridian -106° 

Kaycee

Buffalo

Ashland

Gillette

Sheridan

Moorhead

Moorcroft

Broadus

Miles

City

Birney

Kirby

Rosebud

Rosebud

Monarch

Decker

Locate

Weston

Hampshire

Piney

Newcastle

C6

T7

T4

T3

T5 P11

P9

T10

T16

T15

R1

P16

P17

T18

T19

P18

P13

B2

B1

C5

C4

C3

C2

C1

P15

P14

P12

P10

P6

P5

P7 P8

P4

P2

P1

P3

T8

T9

T14

T17

T13

T2

T1

R2

T6

MONTANA

WYOMING

Sussex

Arvada

Powder River

Structural Basin

boundary

T12

T11

EXPLANATION

Rosebud Creek

Tongue River

Powder River

Cheyenne River

Belle Fourche

 River

Watershed

Aquatic community

 sampling site

 and number

Helena

Powder

River

Structural

Basin Cheyenne

MONTANA

WYOMING

P13

Map area

Aquatics Task Group

The development of CBNG and subsequent disposal of 

ground water from CBNG wells into surface drainages and 

impoundments may degrade aquatic habitats, species, and 

populations. The Aquatics Task Group (ATG) was established 

to address issues related to aquatic biota in the PRB. The ATG’s 

membership includes technical specialists from the Bureau 

of Indian Affairs (BIA), BLM, MDEQ, MFWP, USEPA, U.S. 

Forest Service (USFS), USGS, WDEQ, WGFD, and others. 

Objectives for this group were to (1) develop aquatic habitat 

and species monitoring plans for watersheds with current or 

anticipated CBNG development and (2) make recommendations to PRB IWG regarding measures to avoid or minimize 

effects of CBNG development on aquatic species. If preventing 

substantial development effects is not possible, the task group 

will make recommendations of measures to mitigate CBNG 

development effects and methods to assess the effectiveness of 

the measures.

The ATG developed an aquatic-biota monitoring plan that 

describes monitoring of aquatic biota and their habitat for drainage basins with current and anticipated CBNG development. 

The objectives of this monitoring plan are to (1) establish current conditions for aquatic biota and their habitat and (2) determine existing and potential effects of CBNG discharge waters 

on aquatic life. Although it is too late to establish a true baseline 

of conditions before CBNG development, the current condition 

of aquatic communities and habitat can be assessed.

Sampling to assess the current (2005) condition of aquatic 

communities was conducted by the USGS in cooperation with 

the BLM, MDEQ, MFWP, USEPA, WDEQ, and WGFD. A 

total of 47 sites were sampled (fig. 1). The scope of work varied 

according to the river system and the interests of the cooperators 

from Wyoming (26 sites) and Montana (21 sites) as shown in 

table 1 and described in this fact sheet.

Summary of Aquatic-Community Sampling in 2005

Data collected for the assessment of aquatic communities included measurements for habitat, fish community, algae, 

and benthic macroinvertebrates. Sampling and measurement 

techniques were derived from the USEPA Environmental Monitoring and Assessment Program (EMAP) protocols for habitat 

and fish community (with some modifications) and the USGS 

National Water-Quality Assessment (NAWQA) Program protocols for algae and benthic macroinvertebrates.

Habitat transects were established at all 47 sites (table 1) 

sampled in Montana and Wyoming. Reach lengths in all streams 

except the main stem Powder River were defined as 40 wetted 

channel widths (Peck and others, 2003), with a minimum reach 

length of 200 meters and a maximum reach length of 1,000 

meters. Eleven transects, equally spaced along the reach, were 

established for measurement of variables such as wetted and 

bankfull width, bank and streambed substrate, embeddedness, 

bank angle, canopy cover, and fish cover. At Wyoming sites, 

a longitudinal profile of the streambed, water surface, bankfull 

stage and low terraces, if any, were surveyed as described by 

Harrelson and others (1994). Within each reach, two to four 

cross sections were monumented with rebar when possible for 

Table 1.  Sites sampled as part of aquatic-community monitoring program during 2005.

[X, data were collected; X1, fish community data collected by Wyoming Game and Fish Department; X2, cross-sections completed by the Wyoming Department of Environmental Quality; X3, data collected by the Wyoming Department of Environmental Quality]

Map number USGS station

identification number Site name Habitat transects and cross-sections

Longitudinal 

profiles GPS Mapping Algae Invertebrates Fish community

Major ion 

samples

R1 06295113 Rosebud Creek at Reservation Boundary, near Kirby, MT X X X

R2 06296003 Rosebud Creek at mouth, near Rosebud, MT X X X

T1 06299980 Tongue River at Monarch, WY X X X X X

T2 06305700 Goose Creek near Acme, WY X X X X X

T3 450137106595101 Youngs Creek near Reservation Boundary, near Decker, MT X X X X

T4 445832106551401 Youngs Creek above mouth, near Decker, MT X X X X

T5 445957106524701 Tongue River below Youngs Creek, near Decker, MT X X X X

T6 06306100 Squirrel Creek near Decker, MT X X X X

T7 450047106514201 Squirrel Creek above Mouth at Decker, MT X X X X

T8 06306250 Prairie Dog Creek near Acme, WY X X X X X

T9 06306300 Tongue River at State Line, near Decker, MT X X X X X

T10 451607106372801 Tongue River at Prairie Dog Creek, near Decker, MT X X X X

T11 06307570 Hanging Woman Creek below Horse Creek, near Birney, MT X X X X

T12 451340106295501 Hanging Woman Creek below Hay Gulch, near Birney, MT X X X X

T13 06307600 Hanging Woman Creek near Birney, MT X X X

T14 06307616 Tongue River at Birney Day School Bridge, near Birney, MT X X X

T15 451732106085001 Otter Creek below Taylor Creek, near Otter, MT X X X X

T16 452642106091201 Otter Creek below Tenmile Creek, near Ashland, MT X X X X

T17 06307740 Otter Creek at Ashland, MT X X X

T18 06307830 Tongue River below Brandenberg Bridge, near Ashland, MT X X X

T19 06308400 Pumpkin Creek near Miles City, MT X X X

P1 434056106244101 Powder River above Lone Tree Draw, near Sussex, WY X X X X X1 X

P2 434124106192401 Powder River below Salt Creek, near Sussex, WY X X X X X1 X

P3 435453106104701 Powder River below Willow Creek, near Sussex, WY X X X X X1 X

P4 440919106091401 Powder River above Van Houghton Draw, near Buffalo, WY X X X X X1 X

P5 442538106082001 Powder River below Mitchell Draw, near Arvada, WY X X X X X1 X

P6 441532106251301 Crazy Woman Creek below I-90, near Buffalo, WY X X X X X X X

P7 442817106133001 Crazy Woman Creek near Upper Station, near Arvada, WY X X X X X X X

P8 443025106061601 Powder River below Crazy Woman Creek, near Arvada,WY X X X X X1 X

P9 444857106030401 Powder River above Ivy Creek, near Arvada, WY X X X X X1 X

P10 06324000 Clear Creek near Arvada, WY X X X X X

P11 445339106032501 Powder River below Clear Creek, near Arvada, WY X X X X X1 X

P12 06324500 Powder River at Moorhead, MT X X X X X

P13 06324710 Powder River at Broadus, MT X X X X

P14 06324790 Little Powder River at State Hwy 59, near Gillette, WY X X X X X X

P15 06324970 Little Powder River above Dry Creek, near Weston, WY X X X X X

P16 06325000 Little Powder River at Biddle, MT X X X X

P17 453209105201201 Powder River below Little Powder River, near Broadus, MT X X X X

P18 06326500 Powder River near Locate, MT X X X

B1 06425720 Belle Fourche River below Rattlesnake Creek, near Piney, WY X X X X X

B2 06425900 Caballo Creek at mouth, near Piney, WY X X X X X

C1 06364300 Porcupine Creek near Teckla, WY X X X X X

C2 06364700 Antelope Creek near Teckla, WY X2 X3 X X X

C3 06365900 Cheyenne River near Dull Center, WY X2 X3 X X X

C4 06375600 Little Thunder Creek near Hampshire, WY X X X X X

C5 06376300 Black Thunder Creek near Hampshire, WY X2 X3 X X X

C6 06386500 Cheyenne River near Spencer, WY X2 X3 X X X
Invertebrate sampling at Prairie Dog Creek near Acme, Wyoming (site T8)

(photograph by Kendra Remley).

Powder River above Lone Tree Draw, near Sussex, Wyoming (site P1)

(photograph by Kendra Remley).

Fish community sampling at Tongue River at State line near Decker, Montana

(site T9) (photograph by Mike Sweat). Hanging Woman Creek near Birney, Montana (site T13)

(photograph by Stacey Kinsey).

long-term reference. A 100-particle pebble count was completed 

in at least one riffle cross section and one pool cross section 

(Wolman, 1954). At Montana sites, two to four cross sections 

were monumented and surveyed when possible; however, longitudinal profiles and pebble counts were not done.

Habitat data collection varied between the main stem Powder River and all other streams sampled (table 1). The Powder 

River was sampled differently than the other streams due to its 

continuously shifting sand habitats. The WGFD established 

2-mile study reaches on the main stem Powder River in Wyoming during 2004. WGFD and USGS personnel coordinated 

field efforts and jointly sampled sites on the mainstem Powder 

River in Wyoming in 2005. Fish community and mesohabitat 

mapping was conducted in the spring of the year (pre-runoff) 

and during low-flow conditions in July. WGFD personnel collected fish samples and made warm-water stream assessments 

during both sampling periods following WGFD protocols (Dave 

Zafft, Wyoming Game and Fish Department, written commun., 

2005). USGS personnel provided high-resolution global-positioning system mapping of mesohabitat types (riffle, run, shoal, 

pool, and isolated backwater) for both periods. During low-flow 

sampling of Powder River sites in Wyoming, habitat sampling 

was performed by USGS personnel using a modified version of 

the EMAP and Harrelson and others (1994) protocols. USGS 

personnel also collected samples for algae and benthic macroinvertebrates. Along the main stem Powder River in Montana, 

USGS personnel used WGFD protocols to determine sampling 

reaches and assess fish populations. Stream-habitat transects 

along the main stem Powder River were sampled in the same 

manner in both Wyoming and Montana. A transect was set 

across each habitat sampled for fish, and applicable features 

along each of these transects were recorded following the 

EMAP protocol.

were collected by seining, although sites on the main stem of 

the Tongue River and some of the tributaries to the Tongue 

River were sampled by electrofishing. Fish generally were 

released back to the stream after sampling, but voucher specimens of a few fish were retained for taxonomic confirmation 

and identification of unknown or difficult-to-identify specimens. 

A quality-assurance plan for fish taxonomy was developed for 

this project.

Data Availability

Additional information about the ATG project, including 

the data collected to date are available at URL: http://wy.water.

usgs.gov/projects/atg/. Data which are currently available 

include chlorophyll-a and ash-free dry mass concentrations in 

algae samples and major-ion concentrations in water samples 

collected in conjunction with ecology samples. Water-quality samples were collected only at sites where water quality 

is not currently monitored (table 1) as part of the Water Task 

Group’s surface-water monitoring program. All water-quality 

data collected by the USGS, including major-ion data collected 

as part of the monitoring plan are stored electronically in the 

USGS National Water Information System and are available at 

URL: http://waterdata.usgs.gov/nwis/. More information about 

the PRB IWG and Task Group activities is available at URL: 

http://www.wy.blm.gov/bfo/prbgroup/index.htm.

tioned as the primary sample at sites where riffles were absent. 

The QMH sample was a timed collection (1 hour) of macroinvertebrates from the various microhabitats in the reach, such as 

logs, macrophytes, and soft substrates. The macroinvertebrate 

samples were sent to Utah State University for taxonomic 

analysis.

Algae samples were collected at 24 sites in Wyoming and 

2 sites in Montana near the State line (table 1). At each site 

where riffles were available, semi-quantitative samples of periphytic algae were scraped from 25 rocks and composited into a 

RTH sample following NAWQA protocols (Moulton and others, 

2002). At sites without riffles, periphyton samples were collected from depositional targeted habitat (DTH) in the euphotic 

zone of pools. A subsample of the RTH algae samples was 

frozen on dry ice and sent to the USGS National Water Quality 

Laboratory for analysis of chlorophyll-a and ash-free dry mass. 

The RTH and DTH algae samples were sent to a laboratory for 

taxonomic analysis following procedures described by Charles 

and others (2002).

Fish communities were sampled at each site from a reach 

length of 40 mean-wetted-channel widths following EMAP protocols (Peck and others, 2003) with the exception of sites on the 

Powder River that were described previously. Most fish samples 

References

Charles, D.F., Knowles, Candia, and Davis, R.S., 2002, Protocols for the analysis of algal samples collected as part of the 

U.S. Geological Survey National Water-Quality Assessment 

Program: Philadelphia, Pa., Academy of Natural Sciences, 

Patrick Center for Environmental Research—Phycology Section, Report 02-06, 124 p.

Clark, M.L., Lambing, J.H., and Bobst, A.L., 2005, Surfacewater monitoring in watersheds of the Powder River Basin, 

2005: U.S. Geological Survey Fact Sheet 2005-3137, 4 p. 

[Available online at http://pubs.water.usgs.gov/fs2005-3137/]

Harrelson, C.C., Rawlins, C.L., and Potyondy, J.P., 1994, 

Stream channel reference sites—an illustrated guide to field 

technique: Fort Collins, Colo., U.S. Department of Agriculture, Forest Service, Rocky Mountain Forest and Range 

Experimentation Station, General Technical Report RM-245, 

61 p.

Moulton, S.R. II, Kennen, J.G., Goldstein, R.M., and Hambrook, J.A., 2002, Revised protocols for sampling algal, 

invertebrate, and fish communities as part of the National 

Water-Quality Assessment Program: U.S. Geological Survey 

Open-File Report 02-150, 75 p.

 Peck, D.V., Lazorchak, J.M., and Klemm, D.J., eds., 2003, 

Environmental Monitoring and Assessment Program—

surface waters: Western Pilot Study field operations manual 

for wadeable streams: Washington, D.C., U.S. Environmental 

Protection Agency, 258 p.

Powder River Natural Gas Interagency Working Group, 2004, 

Charter: Buffalo, Wyo., Bureau of Land Management, 

15 p., accessed Dec. 8, 2005, at http://www.wy.blm.gov/bfo/

prbgroup/moucharter.htm

Wolman, M.G., 1954, A method of sampling coarse river bed 

material: Eos Transactions of the American Geophysical 

Union, v. 35 [no. 6], p. 951-956.

Wyoming Oil and Gas Conservation Commission, 2005, digital 

data, accessed Dec. 8, 2005, at http://wogcc.state.wy.us/

coalbedchart.cfm

By Peter R. Wright, David A. Peterson, and Laura L. Hallberg

Layout and graphics by Suzanne C. Roberts

Benthic macroinvertebrates were collected at each of the 

47 sites (table 1) following NAWQA protocols (Moulton and 

others, 2002). At sites where riffles were available in the stream 

reach, riffles were sampled as the richest targeted habitat (RTH). 

Each RTH sample was a composite, semi-quantitative sample 

from five points, with a total sampled area of 1.25 square meters. About 75 percent of the ATG sites sampled in 2005 had 

riffles and RTH samples. A qualitative multi-habitat (QMH) 

sample of macroinvertebrates was collected at all sites and funcFor more information, contact:

Director

U.S. Geological Survey

Wyoming Water Science Center

2617 E. Lincolnway, Suite B

Cheyenne, Wyoming 82001

(307) 778-2931

http://wy.water.usgs.gov/