U.S. Department of the Interior

U.S. Geological Survey

Hydrology of the Black Hills Area, 

South Dakota

Prepared in cooperation with the

South Dakota Department of Environment and Natural Resources

and the West Dakota Water Development District

Water-Resources Investigations Report 02-4094

By Daniel G. Driscoll, Janet M. Carter, Joyce E. Williamson, and Larry D. Putnam
U.S. Department of the Interior

GALE A. NORTON, Secretary

U.S. Geological Survey

Charles G. Groat, Director

The use of firm, trade, and brand names in this report is for identification purposes only and 

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

Rapid City, South Dakota: 2002

For additional information write to:

District Chief

U.S. Geological Survey

1608 Mt. View Road

Rapid City, SD 57702

Copies of this report can be purchased from:

U.S. Geological Survey

Information Services

Building 810

Box 25286, Federal Center

Denver, CO 80225-0286
Contents III

CONTENTS

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

Introduction .......................................................................................................................................................................... 1

Purpose and Scope...................................................................................................................................................... 2

Description of Study Area .......................................................................................................................................... 2

Acknowledgments ...................................................................................................................................................... 4

Hydrogeologic Framework................................................................................................................................................... 4

Climatic Framework ................................................................................................................................................... 5

Geologic Framework .................................................................................................................................................. 10

Regional Geologic Setting................................................................................................................................ 10

Paleostructure ......................................................................................................................................... 10

Stratigraphy ............................................................................................................................................ 13

Local Geologic Setting ..................................................................................................................................... 13

Ground-Water Framework.......................................................................................................................................... 20

Regional Aquifers............................................................................................................................................. 20

Local Aquifers .................................................................................................................................................. 23

Characteristics and Properties of Major Aquifers .................................................................................. 24

Overview of Other Aquifers ................................................................................................................... 31

Surface-Water Framework.......................................................................................................................................... 31

Hydrogeologic Settings .................................................................................................................................... 34

Streamflow Losses............................................................................................................................................ 34

Streamflow Regulation ..................................................................................................................................... 36

Hydrologic Processes and Characteristics............................................................................................................................ 37

Hydrologic Processes ................................................................................................................................................. 37

Ground-Water Characteristics .................................................................................................................................... 38

Water-Level Trends and Comparisons.............................................................................................................. 38

Temporal Trends..................................................................................................................................... 38

Comparisons Between Madison and Minnelusa Aquifers ..................................................................... 38

Comparisons for Other Aquifers ............................................................................................................ 43

Responses to Climatic Conditions.......................................................................................................... 43

Water Quality.................................................................................................................................................... 45

General Characteristics for Major Aquifers ........................................................................................... 50

General Characteristics for Minor Aquifers ........................................................................................... 56

Susceptibility to Contamination ............................................................................................................. 59

Summary Relative to Water Use............................................................................................................. 60

Surface-Water Characteristics .................................................................................................................................... 62

Streamflow Characteristics............................................................................................................................... 62

Streamflow Variability............................................................................................................................ 62

Response to Precipitation ....................................................................................................................... 70

Annual Yield........................................................................................................................................... 77

Water Quality.................................................................................................................................................... 82

Standards and Criteria ............................................................................................................................ 87

Common-ion Chemistry ......................................................................................................................... 87

Anthropogenic Effects............................................................................................................................ 95

Additional Factors Relative to In-Stream Standards .............................................................................. 103
IV Contents

CONTENTS—Continued

Hydrologic Budgets ............................................................................................................................................................. 103

Methods for Estimating Basin Yield and Recharge ................................................................................................... 105

Ground-Water Budgets............................................................................................................................................... 106

Budgets for Madison and Minnelusa Aquifers ................................................................................................ 107

Budgets for Other Bedrock Aquifers ............................................................................................................... 118

Surface-Water Budgets............................................................................................................................................... 120

Combined Ground-Water and Surface-Water Budgets .............................................................................................. 120

Evaluation of Hydrologic Budgets............................................................................................................................. 122

Madison and Minnelusa Flow System ................................................................................................................................. 123

Isotope Information.................................................................................................................................................... 123

Background Information and Composition of Recharge Water....................................................................... 123

Isotope Distributions and General Considerations........................................................................................... 131

Flowpaths, Ages, and Mixing Conditions.................................................................................................................. 135

Rapid City Area ............................................................................................................................................... 135

Northern Black Hills ........................................................................................................................................ 137

Southern Black Hills ........................................................................................................................................ 139

Interactions Between Aquifers................................................................................................................................... 140

Influence on Overall Hydrology of Black Hills Area ................................................................................................ 143

References............................................................................................................................................................................ 145

FIGURES

1. Map showing area of investigation for the Black Hills Hydrology Study............................................................ 3

2. Map showing present-day structural and physiographic features in the northern Great Plains area.................... 4

3. Map showing monthly precipitation distribution for October 1995 ..................................................................... 6

4. Isohyetal map showing distribution of average annual precipitation for Black Hills area,

water years 1950-98.............................................................................................................................................. 7

5. Boxplots showing distribution of annual precipitation for the study area and counties within

the study area, water years 1931-98...................................................................................................................... 8

6. Boxplots showing distribution of monthly precipitation for the study area, water years 1931-98....................... 8

7. Graph showing mean monthly precipitation for study area and selected counties, water years 1931-98 ............ 9

8. Graphs showing long-term trends in precipitation for the Black Hills area, water years 1931-98....................... 9

9. Stratigraphic section for the Black Hills............................................................................................................... 11

10. Map showing regional paleostructure during Jurassic and Cretaceous time in the

western interior of the United States..................................................................................................................... 12

11. Maps showing approximate extent of rocks in the northern Great Plains area for

selected geologic periods ...................................................................................................................................... 14

12. Generalized correlation chart for Paleozoic-age rocks in Montana, North Dakota,

South Dakota, and Wyoming ................................................................................................................................ 15

13. Generalized correlation chart for Mesozoic- and Cenozoic-age rocks in Montana,

North Dakota, South Dakota, and Wyoming ........................................................................................................ 16

14. Map showing distribution of hydrogeologic units in the Black Hills area ........................................................... 17

15. Geologic cross section A-A′ ................................................................................................................................. 19

16. Schematic showing simplified hydrogeologic setting of the Black Hills area ..................................................... 21

17. Map showing general direction of ground-water flow in regional aquifer system 

within Paleozoic aquifer units............................................................................................................................... 22

18. Boxplots showing distribution of well yields from selected aquifers................................................................... 26

19-23. Maps showing:

19. Potentiometric surface of the Madison aquifer and locations of major artesian springs............................. 29

20. Potentiometric surface of the Minnelusa aquifer and locations of major artesian springs.......................... 30

21. Saturated thickness of the Madison aquifer................................................................................................. 32

22. Saturated thickness of the Minnelusa aquifer.............................................................................................. 33

23. Hydrogeologic settings for the Black Hills area.......................................................................................... 35
Contents V

FIGURES—Continued

24. Schematic diagram illustrating hydrologic processes........................................................................................... 37

25. Map showing location of observation wells for which hydrographs are presented.............................................. 39

26-30. Hydrographs illustrating:

26. Temporal trends in ground-water levels ...................................................................................................... 40

27. General similarities in water levels for some colocated Madison/Minnelusa

wells with confined conditions.................................................................................................................... 42

28. Distinct hydraulic separation for two Madison/Minnelusa well pairs with unconfined conditions............ 42

29. Generally separated water levels for some colocated Madison/Minnelusa wells ....................................... 44

30. Colocated Minnelusa/Minnekahta and Deadwood/Madison wells ............................................................. 45

31. Graphs showing relations between dissolved solids and specific conductance for the major aquifers ................ 51

32-36. Maps showing:

32. Distribution of specific conductance in the Madison aquifer...................................................................... 52

33. Distribution of hardness in the Inyan Kara aquifer ..................................................................................... 53

34. Stiff diagrams showing the distribution of common-ion chemistry in the Madison aquifer....................... 54

35. Stiff diagrams showing the distribution of common-ion chemistry in the Minnelusa aquifer.................... 55

36. Distribution of radon concentrations in the Deadwood aquifer .................................................................. 57

37. Graphs showing relations between dissolved solids and specific conductance for the minor aquifers................ 58

38. Boxplots of concentrations of nitrite plus nitrate for selected aquifers................................................................ 59

39. South Dakota irrigation-water classification diagram for selected aquifers ......................................................... 61

40. Duration curves of daily mean streamflow for basins representative of hydrogeologic settings ......................... 65

41. Graphs showing mean monthly streamflow for basins representative of hydrogeologic settings ........................ 66

42. Boxplots showing distribution of annual yield for basins representative of hydrogeologic settings.................... 68

43-48. Graphs showing:

43. Relations between annual streamflow and precipitation for crystalline core basins................................... 72

44. Relations between annual runoff efficiency and precipitation for crystalline core basins .......................... 74

45. Relations between annual streamflow and precipitation for loss zone basins............................................. 74

46. Long-term trends in annual streamflow for station 06402000, relative to annual precipitation ................. 75

47. Relations between annual streamflow and precipitation for exterior basins ............................................... 76

48. Relations between annual runoff efficiency and precipitation for exterior basins ...................................... 77

49. Map showing basin yields for selected streamflow-gaging stations..................................................................... 79

50. Map showing comparison between surface-drainage areas and contributing ground-water

areas for streamflow-gaging stations in Limestone Plateau area.......................................................................... 80

51. Schematic diagram illustrating recharge and streamflow characteristics for selected outcrop types................... 81

52. Map showing generalized average annual yield efficiency, water years 1950-98 ................................................ 83

53. Graphs showing relations between yield efficiency and precipitation for selected 

streamflow-gaging stations ................................................................................................................................... 84

54. Map showing estimated annual yield potential for the Black Hills area, water years 1950-98............................ 86

55. Graphs showing relations between hardness and freshwater aquatic-life standards for

acute and chronic toxicity of selected trace elements........................................................................................... 89

56. Graph showing relations between dissolved solids and specific conductance by hydrogeologic settings ........... 90

57. Graphs showing relations between specific conductance and streamflow for selected sampling

sites by hydrogeologic setting............................................................................................................................... 91

58. Trilinear diagrams showing proportional concentrations of common ions by hydrogeologic setting.................. 92

59. Stiff diagrams showing median concentrations by hydrogeologic setting............................................................ 93

60. Map showing spatial distribution of median sulfate concentrations in surface water .......................................... 94

61. Map showing spatial distribution of maximum selenium concentrations in surface water .................................. 96

62. Maps showing locations of selected water-quality sampling sites used for analysis

of anthropogenic effects in Lawrence County and Rapid Creek Basin ................................................................ 97

63. Graph showing downstream progression of pH for selected streams influenced by acid-mine drainage ............ 98

64. Graph showing comparison of dissolved copper concentrations to hardness-dependent

chronic and acute aquatic-life criteria for Bear Butte Creek near Deadwood ...................................................... 99

65. Map showing spatial distribution of maximum arsenic concentrations in surface water ..................................... 101
VI Contents

FIGURES—Continued

66. Boxplots of concentrations of dissolved nitrite plus nitrate by hydrogeologic setting......................................... 102

67. Boxplots of concentrations of dissolved nitrite plus nitrate within the Rapid Creek Basin ................................. 104

68. Graph showing annual recharge to the Madison and Minnelusa aquifers, water years 1931-98,

in the Black Hills of South Dakota and Wyoming................................................................................................ 107

69. Map showing subareas, generalized ground-water flow directions, and flow zones for the Madison aquifer..... 112

70. Map showing subareas, generalized ground-water flow directions, and flow zones

for the Minnelusa aquifer...................................................................................................................................... 113

71. Schematic diagram showing average hydrologic budget components for study area,

water years 1950-98.............................................................................................................................................. 121

72. Schematic showing generalized average streamflow relative to surface geology and depletions ........................ 122

73. Graph showing relation between δ18O and δD in Black Hills samples in comparison to

the Global Meteoric Water Line ........................................................................................................................... 124

74. Map showing generalized distribution of δ18O in surface water and ground water in near-recharge areas......... 126

75. Graphs showing temporal variation of δ18O for selected sites ............................................................................. 127

76. Graph showing estimated tritium concentrations in precipitation for Black Hills

area and decay curves for selected years .............................................................................................................. 128

77. Graphs showing monthly tritium concentrations in precipitation at Ottawa, Canada .......................................... 129

78. Schematic diagrams illustrating mixing models for age dating for various ground-water

flow conditions...................................................................................................................................................... 130

79. Decay-curve family for delayed-arrival mixing model for a 1995 sampling date................................................ 131

80. Map showing distribution of δ18O in samples from selected Madison and Minnelusa wells

and springs in the Black Hills area ....................................................................................................................... 132

81. Map showing tritium occurrence for selected sample sites in Black Hills area ................................................... 134

82. Boxplots of tritium concentrations for selected ground-water and surface-water samples

collected during 1990-98 in the Black Hills area.................................................................................................. 135

83. Map showing concentrations of δ18O in Madison and Minnelusa aquifers in Rapid City area ........................... 136

84. Map showing distribution of δ18O in selected Madison wells and springs and generalized

flowpaths in the Black Hills of South Dakota and Wyoming ............................................................................... 138

85. Schematic showing breccia pipes and caves in relation to the hydrogeologic setting

of the Black Hills area........................................................................................................................................... 143

TABLES

1. Summary of the characteristics of major and Precambrian aquifers in the study area.......................................... 25

2. Estimates of hydraulic conductivity, transmissivity, storage coefficient, and porosity from

previous investigations........................................................................................................................................... 27

3. Summary of loss thresholds from Black Hills streams to bedrock aquifers.......................................................... 36

4. Water-quality criteria, standards, or recommended limits for selected properties and constituents ..................... 46

5. Summary of selected site information and flow characteristics for streamflow-gaging stations

representative of hydrogeologic settings ............................................................................................................... 63

6. Summary of regression information for limestone headwater basins.................................................................... 71

7. Summary of regression information for artesian spring basins ............................................................................. 75

8. Summary of information used in analysis of yield characteristics........................................................................ 78

9. Surface-water-quality standards for selected physical properties and constituents............................................... 88

10. Summary of regression information (dissolved solids versus specific conductance), by

hydrogeologic setting............................................................................................................................................. 90

11. Estimates of average precipitation, precipitation recharge, runoff, total yield, and evapotranspiration

for the study area, water years 1950-98................................................................................................................. 105

12. Recharge factors and outcrop areas for bedrock aquifers...................................................................................... 105

13. Estimated annual hydrologic budget components for the Madison and Minnelusa aquifers,

water years 1931-98, for the Black Hills of South Dakota and Wyoming ............................................................ 108

14. Average hydrologic budgets for the Madison and Minnelusa aquifers ................................................................. 110
Contents VII

TABLES—Continued

15. Hydrologic budgets, by subareas, for the Madison and Minnelusa aquifers in the Black Hills area,

water years 1987-96............................................................................................................................................... 114

16. Average ground-water budgets for bedrock aquifers, water years 1950-98 .......................................................... 119

17. Average surface-water budgets for study area, water years 1950-98 .................................................................... 120

18. Selected hydraulic and geochemical information for major artesian springs........................................................ 141

CONVERSION FACTORS

Temperature in degrees Celsius (°C) may be converted to degrees Fahrenheit (°F) as follows:

°F = (1.8 × °C) + 32

Temperature in degrees Fahrenheit (°F) may be converted to degrees Celsius (°C) as follows:

°C = (°F - 32) / 1.8

Sea level: In this report, "sea level" refers to the National Geodetic Vertical Datum of 1929 (NGVD 

of 1929)—a geodetic datum derived from a general adjustment of the first-order level nets of both 

the United States and Canada, formerly called Sea Level Datum of 1929.

Water year (WY): Water year is the 12-month period, October 1 through September 30, and is designated by the calendar year in which it ends. Thus, the water year ending September 30, 1998, is 

called the “1998 water year.”

Multiply By To obtain

acre 4,047 square meter

acre 0.4047 hectare

acre-foot (acre-ft) 1,233 cubic meter 

acre-foot (acre-ft) 0.001233 cubic hectometer 

acre-foot per year (acre-ft/yr) 1,233 cubic meter per year

acre-foot per year (acre-ft/yr) 0.001233 cubic hectometer per year

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

foot (ft) 0.3048 meter

foot per day (ft/d) 0.3048 meter per day

foot squared per day (ft2

/d) 0.09290 meter squared per day 

inch 2.54 centimeter

inch 25.4 millimeter

inch per year (in/yr) 25.4 millimeter per year

mile (mi) 1.609 kilometer

square foot (ft2) 929.0 square centimeter

square mile (mi2) 259.0 hectare

square mile (mi2) 2.590 square kilometer 

Introduction 1

Hydrology of the Black Hills Area, South Dakota

By Daniel G. Driscoll, Janet M. Carter, Joyce E. Williamson, and Larry D. Putnam

ABSTRACT

The Black Hills Hydrology Study was initiated in 1990 to assess the quantity, quality, and 

distribution of surface water and ground water in 

the Black Hills area of South Dakota. This report 

summarizes the hydrology of the Black Hills area 

and the results of this long-term study.

The Black Hills area of South Dakota and 

Wyoming is an important recharge area for several 

regional, bedrock aquifer systems and various 

local aquifers; thus, the study focused on describing the hydrologic significance of selected bedrock aquifers. The major aquifers in the Black 

Hills area are the Deadwood, Madison, Minnelusa, 

Minnekahta, and Inyan Kara aquifers. The highest 

priority was placed on the Madison and Minnelusa 

aquifers, which are used extensively and heavily 

influence the surface-water resources of the area. 

Within this report, the hydrogeologic framework of the area, including climate, geology, 

ground water, and surface water, is discussed. 

Hydrologic processes and characteristics for 

ground water and surface water are presented. For 

ground water, water-level trends and comparisons 

and water-quality characteristics are presented. 

For surface water, streamflow characteristics, 

responses to precipitation, annual yields and yield 

efficiencies, and water-quality characteristics are 

presented. Hydrologic budgets are presented for 

ground water, surface water, and the combined 

ground-water/surface-water system. A summary 

of study findings regarding the complex flow 

systems within the Madison and Minnelusa 

aquifers also is presented.

INTRODUCTION

The Black Hills area is an important resource 

center that provides an economic base for western 

South Dakota through tourism, agriculture, the timber 

industry, and mineral resources. In addition, water originating from the area is used for municipal, industrial, 

agricultural, and recreational purposes throughout 

much of western South Dakota. The Black Hills area 

also is an important recharge area for aquifers in the 

northern Great Plains. 

Population growth, resource development, and 

periodic droughts have the potential to affect the quantity, quality, and availability of water within the Black 

Hills area. Because of this concern, the Black Hills 

Hydrology Study was initiated in 1990 to assess the 

quantity, quality, and distribution of surface water and 

ground water in the Black Hills area of South Dakota 

(Driscoll, 1992). This long-term study has been a cooperative effort between the U.S. Geological Survey 

(USGS), the South Dakota Department of Environment 

and Natural Resources, and the West Dakota Water 

Development District, which represents various local 

and county cooperators. 

The specific objectives of the Black Hills 

Hydrology Study included:

1. Inventorying and describing precipitation amounts, 

streamflow rates, ground-water levels of selected 

aquifer units, and selected water-quality characteristics for the Black Hills area.
2 Hydrology of the Black Hills Area, South Dakota

2. Developing hydrologic budgets to define relations 

among precipitation, streamflow, and aquifer 

response for selected Black Hills watersheds.

3. Describing the significance of the bedrock aquifers 

in the Black Hills area hydrologic system, with an 

emphasis on the Madison and Minnelusa aquifers, 

through determination of:

a. aquifer properties (depth, thickness, structure, 

storage coefficient, hydraulic conductivity, 

etc.);

b. the hydraulic connection between the aquifers;

c. the source aquifer(s) of springs;

d. recharge and discharge rates, and gross volumetric budgets; and

e. regional flow paths.

4. Developing conceptual models of the hydrogeologic system for the Black Hills area.

Purpose and Scope

The purpose of this report is to summarize the 

hydrology of the Black Hills area and present major 

findings pertinent to the objectives of the Black Hills 

Hydrology Study. The information summarized in this 

report has been presented in more detail in previous 

reports prepared as part of the study. Because the Black 

Hills area of South Dakota and Wyoming is an important recharge area for several regional, bedrock aquifers 

and various local aquifers, the study concentrated on 

describing the hydrogeology and hydrologic significance of selected bedrock aquifers. The highest priority 

was placed on the Madison and Minnelusa aquifers 

because: (1) these aquifers are heavily used and could 

be developed further; (2) these aquifers are connected 

to surface-water resources through streamflow loss 

zones and large springs; and (3) hydraulic connection 

between these aquifers is extremely variable. The 

Deadwood and Minnekahta aquifers had a lower priority because they are used less and have less influence 

on the hydrologic system. The fractured Precambrian 

rocks, Inyan Kara Group, and various local aquifers, 

including minor bedrock aquifers and unconsolidated 

aquifers, had the lowest priorities because: (1) the Precambrian and local aquifers are not regional aquifers 

with regional flowpaths; and (2) the Inyan Kara Group 

is not used as extensively in the Black Hills area as the 

other priority units. 

Hydrologic analyses within this report generally 

are by water year, which represents the period from 

October 1 through September 30. Discussions of timeframes refer to water years, rather than calendar years, 

unless specifically noted otherwise.

Description of Study Area

The study area for the Black Hills Hydrology 

Study consists of the topographically defined Black 

Hills and adjacent areas located in western South 

Dakota (fig. 1). Outcrops of the Madison Limestone 

and Minnelusa Formation, as well as the generalized 

outer extent of the Inyan Kara Group, which approximates the outer extent of the Black Hills area, also are 

shown in figure 1. The Black Hills are situated between 

the Cheyenne and Belle Fourche Rivers. The Belle 

Fourche River is the largest tributary to the Cheyenne 

River. The study area includes most of the larger communities in western South Dakota and contains about 

one-fifth of the State’s population.

The Black Hills uplift formed as an elongated 

dome about 60 to 65 million years ago during the Laramide orogeny (Darton and Paige, 1925). The dome 

trends north-northwest and is about 120 mi long and 

60 mi wide. Land-surface altitudes range from 7,242 ft 

above sea level at Harney Peak to about 3,000 ft in the 

adjacent plains. Most of the higher altitudes are heavily 

forested with ponderosa pine, which is the primary 

product of an active timber industry. White spruce, 

quaking aspen, paper birch, and other native trees and 

shrubs are found in cooler, wetter areas (Orr, 1959). 

The lower altitude areas surrounding the Black Hills 

primarily are urban, suburban, and agricultural. 

Numerous deciduous species such as cottonwood, ash, 

elm, oak, and willow are common along streams in the 

lower altitudes. Rangeland, hayland, and winter wheat 

farming are the principal agricultural uses for dryland 

areas. Alfalfa, corn, and vegetables are produced in 

bottom lands and in irrigated areas. Various other 

crops, primarily for cattle fodder, are produced in both 

dryland areas and in bottom lands.

Beginning in the 1870’s, the Black Hills have 

been explored and mined for many commodities 

including gold, silver, tin, tungsten, mica, feldspar, 

bentonite, beryl, lead, zinc, uranium, lithium, sand, 

gravel, and oil (U.S. Department of Interior, 1967). 

Mines within the study area have used various techniques including placer mining, underground mining, 

and open-pit mining. 
Introduction 3

Figure 1. Area of investigation for the Black Hills Hydrology Study.

N. Fork Rapid Cr

Belle Fourche

Reservoir

FOURCHE

Victoria

Spring

Rhoads Fork

Coolidge

Highland

Angostura

Reservoir

Castl e Cr

N. Fork Castle Cr

Hell

Canyon

Canyon

Red

Bear

Gulch

Creek

Crow

Sheridan

Lake

Hot Brook Canyon

Cox

Lake

Deerfield

Reservoir

Pactola

Reservoir

Indian Cr

Horse

Creek

Owl

BELLE

Creek

RIVER

REDWATER

R I VER

Creek

Cr

Little Spearfish

Spearfish

Creek

Spearfish

Whitewood

Creek

Creek

Bear

Butte

Elk

Elk

Creek

Creek

Creek

Boxelder

Rapid

Rapid

Cold

Creek

Creek

Creek

Spring

Creek

French

Creek

Creek

Creek

Grace

Creek

Creek

Creek

S. Fork

Redbird

Gillette

S. Fork Rapid Cr

Battle

French

Beaver

Beaver

Creek

Creek

Creek

Creek

Creek

Fall R

Hat

Creek

Creek

Horsehead

CHEYENNE

RIVER

Cottonwood

Hay Creek

Bottom

False

Creek

Spokane

Lame

Johnny

Higgins

Beaver

Cr

Whitetail

Cr

Cr

Cr Cr

Gulch

Annie

Squaw

Deadwood

Creek

Alkali

Iron Cr

Elk

Little

Creek

Castle

Castle

Creek

Creek

Bear Gulch

Cr Strawberry

Boles

Canyon

Beaver

Spring

C s

reek

Creek Canyon

Canyon

Whitewood

Spearfish

Saint

Onge

DEADWOOD

Lead

BELLE FOURCHE

Newell

STURGIS

Blackhawk

Piedmont

Tilford

Box Elder 

Hill City

Hermosa

CUSTER

HOT SPRINGS

Edgemont

Minnekahta

Tinton Central

City

Roubaix

Nemo

Vale

Nisland

Hayward

Keystone

Rochford

Pringle

Fairburn

Buffalo Gap

Dewey

Cascade

Springs

Igloo

Provo

Oral

Rockerville

RAPID CITY

LIMESTONE PLATEAU

 Wind Cave

National Park

Jewel Cave

National

Monument

Mt. Rushmore

National

Memorial

CUSTER

STATE

PARK

Wind

Cave

Harney

Peak

x

Ellsworth

Air Force

Base

BUTTE CO

LAWRENCE CO MEADE CO

PENNINGTON CO

CUSTER CO

FALL RIVER CO

WYOMING

SOUTH DAKOTA

0 10 20

0 10 20 MILES

KILOMETERS

APPROXIMATE EXTENT OF THE BLACK

 HILLS AREA, REPRESENTED BY

 GENERALIZED OUTER EXTENT OF 

 INYAN KARA GROUP (modified

 from Strobel and others, 1999)

OUTCROP OF MADISON LIMESTONE

 (from Strobel and others, 1999)

OUTCROP OF MINNELUSA FORMATION

 (from Strobel and others, 1999)

SOUTH DAKOTA

Area

shown

Black

Hills

EXPLANATION

104o 45' 103o

30'

15' 103o

30'

44o

45'

15'

44o

45'

30'

43o

15'

Missouri River

Base modified from U.S. Geological Survey digital data,

1:100,000, 1977, 1979, 1981, 1983, 1985

Rapid City, Office of City Engineer map, 1:18,000, 1996

Universal Transverse Mercator projection, zone 13
4 Hydrology of the Black Hills Area, South Dakota

Acknowledgments

The authors acknowledge the efforts of the West 

Dakota Water Development District for helping to 

develop and support the Black Hills Hydrology Study. 

West Dakota’s coordination of various local and county 

cooperators has been a key element in making this 

study possible. The authors also recognize the 

numerous local and county cooperators represented by 

West Dakota, as well as the numerous private citizens 

who have helped provide guidance and support for the 

Black Hills Hydrology Study. The South Dakota 

Department of Environment and Natural Resources has 

provided support and extensive technical assistance to 

the study. In addition, the authors acknowledge the 

input and technical assistance from many faculty and 

students at the South Dakota School of Mines and 

Technology.

HYDROGEOLOGIC FRAMEWORK

 The Black Hills are located within the Great 

Plains physiographic province in western South Dakota 

and eastern Wyoming (fig. 2). The Black Hills strongly 

influence the hydrology of western South Dakota and 

northeastern Wyoming. Many streams in western 

South Dakota originate in the Black Hills, and major 

bedrock aquifers are recharged along outcrop areas in 

the Black Hills. Ground and surface water interact 

extensively in the Black Hills, and both streamflow and 

aquifer recharge are influenced by climatic conditions. 

Overviews of the climate, geology, ground water, and 

surface water are provided in the following sections.

Figure 2. Present-day structural and physiographic features in the northern Great Plains area (modified from 

Peterson, 1981, and Busby and others, 1995).

SALT LAKE

CITY

HELENA

CHEYENNE LINCOLN

PIERRE

BISMARCK

MONTANA

IDAHO

UTAH

COLORADO

NEBRASKA

SOUTH DAKOTA

NORTH DAKOTA

WYOMING

UNITED

CANADA

STATES

MONTANA

IDAHO

UTAH

COLORADO

NEBRASKA

SOUTH DAKOTA

NORTH DAKOTA

WYOMING

UNITED

CANADA

STATES

Approximate

 boundary of

 Williston

 Basin

Area of

Sioux Uplift

WILLISTON BASIN

BOWDOIN

DOME

CEDAR CREEK

ANTICLINE

NESSON

ANTICLINE

HINSDALE FAULT

CAT CREEK FAULT

LAKE BASIN FAULT

WILLOW CREEK

FAULT

WHEATLAND

SYNCLINE

CASPER

ARCH

CHADRON ARCH

NYE-BOWLER

FAULT

POPLAR FAULT

WELDON BROCKTON FAULT

SUMATRA

SYNCLINE

SWEETGRASS ARCH

BLOOD CREEK

SYNCLINE

BULL MOUNTAIN

BASIN

CRAZY

MOUNTAINS

BASIN

POWDER

RIVER

BASIN

CRAZY

MOUNTAINS

BASIN

GREEN

RIVER

BASIN

OVERTHRUST

BELT

RED

DESERT

BASIN

POWDER

RIVER

BASIN

HANNA

BASIN LARAMIE

BASIN ALLIANCE BASIN

WASHAKIE

BASIN

CASPER

FAULT MTN

MILES CITY

ARCH

GREAT

CENTRAL

PLAINS

LOWLANDS

PHYSIOGRAPHIC

PHYSIOGRAPHIC

PROVINCE

PROVINCE

Platte

White

Platte

Platte

North

River

River

River

River

River

River

River

River

River

North

Souris

Red

River

River

River

Cheyenne

Belle

Yellowstone

Powder

Little

Missouri

Missouri

Missouri

Fourche

River

S.

of

the

POPLAR

DOME

PORCUPINE

DOME

BEARPAW

UPLIFT

SWEETWATER

UPLIFT

HARTVILLE

UPLIFT

Judith Mts

Big

Snowy

Mts

Little Rocky

Mts

Little

Beartooth Mts Beartooth Mts

Absaroka Mts

Wind River Mts

Laramie Mts

Bighorn Mts

Owl Creek Mts

BeltMts

Pryor Mts

ROCK

SPRINGS

UPLIFT

Medicine

Bow Mts

Sierra

Uinta Mts

Madre

Mts

BLACK

HILLS

UPLIFT

42o

44o

46o

48o

49o 112o

110o

108o 106o 104o 102o 100o 98o

0 100 200 MILES

0 100 200 KILOMETERS
Climatic Framework 5

Climatic Framework

The overall climate of the Black Hills area is 

continental, with generally low precipitation amounts, 

hot summers, cold winters, and extreme variations in 

both precipitation and temperatures (Johnson, 1933). 

Local climatic conditions are affected by topography, 

with generally lower temperatures and higher precipitation at the higher altitudes. The average annual temperature is 43.9°F (U.S. Department of Commerce, 

1999) and ranges from 48.7°F at Hot Springs to 

approximately 37°F near Deerfield Reservoir.

Precipitation data sets used for this study generally were taken from Driscoll, Hamade, and Kenner 

(2000), who summarized available precipitation data 

(1931-98) for the Black Hills area. These investigators 

compiled monthly precipitation records for 52 longterm precipitation gages operated by National Oceanic 

and Atmospheric Administration (1998) and 42 shortterm precipitation gages operated by the USGS. These 

data sets are available on the World Wide Web at 

http://sd.water.usgs.gov/projects/bhhs/precip/ 

home.htm. A geographic information system (GIS) 

was used by Driscoll, Hamade, and Kenner (2000) to 

generate spatial distributions of monthly precipitation 

data for 1,000-by-1,000-meter grid cells for the study 

area; an example is shown in figure 3. Monthly distributions were composited to produce annual distributions for counties within the study area and for drainage 

areas of selected streamflow-gaging stations; these data 

sets were presented by Driscoll and Carter (2001). The 

precipitation distributions were used extensively for 

various applications including evaluating responses of 

ground-water levels and streamflow to precipitation, 

estimating precipitation recharge for bedrock aquifers, 

and developing long-term hydrologic budgets.

Spatial precipitation patterns in the Black Hills 

area are highly influenced by orography, as shown by 

an isohyetal map (fig. 4) for 1950-98, which is the 

period commonly used for hydrologic budgets presented in this report. Areas of relatively low precipitation occur in the low altitudes around the periphery of 

the Black Hills. Most areas with altitudes exceeding 

6,000 ft above sea level have average annual precipitation in excess of 19 inches, with the largest amounts 

occurring in the northern Black Hills near Lead, where 

the average annual precipitation (1950-98) exceeds 

28 inches. Orographic effects also are apparent in the 

high-altitude areas near Harney Peak. 

Local conditions also are affected by regional 

climatic patterns, with the northern Black Hills influenced primarily by moist air currents from the northwest, and the southern Black Hills influenced primarily 

by drier air currents from the south-southeast. As a 

result, annual precipitation averages about 16 to 

17 inches for most of Fall River County (fig. 4) and is 

much less than parts of Lawrence and Meade Counties 

that have comparable altitudes. Boxplots showing the 

distribution of annual precipitation for the study area 

and for counties within the study area during 1931-98 

are presented in figure 5. For the study area, the longterm average of 18.61 inches is slightly larger than the 

median (50th percentile) of 17.96 inches. The 90th percentile indicates that annual precipitation over the 

study area is less than about 23.70 inches 90 percent of 

the time. Annual precipitation for both Butte and Fall 

River Counties is less than the long-term average for 

the study area about 75 percent of the time. 

The largest precipitation amounts typically occur 

during May and June, and the smallest amounts typically occur during November through February (fig. 6). 

The most variable month is May, during which precipitation has ranged from a minimum of about 0.4 inch to 

a maximum of 8.5 inches. The seasonal distribution of 

precipitation is fairly uniform throughout the study 

area; however, Lawrence County receives slightly 

larger proportions of its annual precipitation during 

winter months than the other counties (fig. 7).

Long-term (1931-98) trends in precipitation 

(fig. 8) are an important consideration for hydrologic 

analysis for the Black Hills area. Figure 8A shows that 

annual precipitation for the study area averages 

18.61 inches and has ranged from 10.22 inches in 1936 

to 27.39 inches in 1995. Figure 8B shows that the associated departures (from the average) have ranged from 

a deficit (-) of 8.39 inches to a surplus (+) of 

8.78 inches, respectively. The cumulative trends are 

readily apparent from figure 8C, with the most pronounced trends identified by the longest and steepest 

line segments. Sustained periods of generally deficit 

precipitation occurred during 1931-40 and 1948-61. 

Sustained periods of generally surplus precipitation 

occurred during 1941-47, 1962-68, and 1993-98. The 

middle to late 1990’s stand out as the wettest period 

since 1931.
6 Hydrology of the Black Hills Area, South Dakota

Figure 3. Monthly precipitation distribution for October 1995 (from Driscoll, Hamade, and Kenner, 2000).

N. Fork Rapid Cr

Belle Fourche

Reservoir

FOURCHE

Victoria

Spring

Rhoads Fork

Coolidge

Highland

Angostura

Reservoir

Castl e Cr

N. Fork Castle Cr

Hell

Canyon

Canyon

Red

Bear

Gulch

Creek

Crow

Sheridan

Lake

Hot Brook Canyon

Cox

Lake

Deerfield

Reservoir

Pactola

Reservoir

Indian Cr

Horse

Creek

Owl

BELLE

Creek

RIVER

REDWATER

R I VER

Creek

Cr

Little Spearfish

Spearfish

Creek

Spearfish

Whitewood

Creek

Creek

Bear

Butte

Elk

Elk

Creek

Creek

Creek

Boxelder

Rapid

Rapid

Creek

Creek

Creek

Spring

Creek

French

Creek

Creek

Creek

Grace

Creek

Creek

Creek

S. Fork

Redbird

Gillette

S. Fork Rapid Cr

Battle

French

Beaver

Beaver

Creek

Creek

Creek

Creek

Creek

Fall R

Hat

Creek

Creek

Horsehead

CHEYENNE

RIVER

Cottonwood

Hay Creek

Bottom

False

Creek

Spokane

Lame

Johnny

Higgins

Beaver

Cr

Whitetail

Cr

Cr

Cr Cr

Gulch

Annie

Squaw

Deadwood

Creek

Alkali

Iron Cr

Elk

Little

Creek

Castle

Castle

Creek

Creek

Bear Gulch

Cr Strawberry

Boles

Canyon

Canyon

Canyon

Cold

Beaver

Spring

C s

reek

Creek

Whitewood

Spearfish

Saint

Onge

DEADWOOD

Lead

BELLE FOURCHE

Newell

STURGIS

Blackhawk

Piedmont

Tilford

Box Elder 

Hill City

Hermosa

CUSTER

HOT SPRINGS

Edgemont

Minnekahta

Tinton Central

City

Roubaix

Nemo

Vale

Nisland

Hayward

Keystone

Rochford

Pringle

Fairburn

Buffalo Gap

Dewey

Cascade

Springs

Igloo

Provo

Oral

Rockerville

RAPID CITY

LIMESTONE PLATEAU

 Wind Cave

National Park

Jewel Cave

National

Monument

Mt. Rushmore

National

Memorial

CUSTER

STATE

PARK

Wind

Cave

Harney

Peak

x

Ellsworth

Air Force

Base

BUTTE CO

LAWRENCE CO MEADE CO

PENNINGTON CO

CUSTER CO

FALL RIVER CO

WYOMING

SOUTH DAKOTA

0 10 20

0 10 20 MILES

KILOMETERS

PRECIPITATION, IN INCHES

Less than 2

EXPLANATION

2 to 3

3 to 4

4 to 5

5 to 6

Greater than 6

104o 45' 103o

30'

15' 103o

30'

44o

45'

15'

44o

45'

30'

43o

15'

Base modified from U.S. Geological Survey digital data,

1:100,000, 1977, 1979, 1981, 1983, 1985

Rapid City, Office of City Engineer map, 1:18,000, 1996

Universal Transverse Mercator projection, zone 13
Climatic Framework 7

Figure 4. Isohyetal map showing distribution of average annual precipitation for Black Hills area, water years 

1950-98 (from Carter, Driscoll, and Hamade, 2001).

N. Fork Rapid Cr

Belle Fourche

Reservoir

FOURCHE

Victoria

Spring

Rhoads Fork

Coolidge

Highland

Angostura

Reservoir

Castl e Cr

N. Fork Castle Cr

Hell

Canyon

Canyon

Red

Bear

Gulch

Creek

Crow

Sheridan

Lake

Hot Brook Canyon

Cox

Lake

Deerfield

Reservoir

Pactola

Reservoir

Indian Cr

Horse

Creek

Owl

BELLE

Creek

RIVER

REDWATER

R I VER

Creek

Cr

Little Spearfish

Spearfish

Creek

Spearfish

Whitewood

Creek

Creek

Bear

Butte

Elk

Elk

Creek

Creek

Creek

Boxelder

Rapid

Rapid

Creek

Creek

Creek

Spring

Creek

French

Creek

Creek

Creek

Grace

Creek

Creek

Creek

S. Fork

Redbird

Gillette

S. Fork Rapid Cr

Battle

French

Beaver

Beaver

Creek

Creek

Creek

Creek

Creek

Fall R

Hat

Creek

Creek

Horsehead

CHEYENNE

RIVER

Cottonwood

Hay Creek

Bottom

False

Creek

Spokane

Lame

Johnny

Higgins

Beaver

Cr

Whitetail

Cr

Cr

Cr Cr

Gulch

Annie

Squaw

Deadwood

Creek

Alkali

Iron Cr

Elk

Little

Creek

Castle

Castle

Creek

Creek

Bear Gulch

Cr Strawberry

Boles

Canyon

Canyon

Canyon

Cold

Beaver

Spring

C s

reek

Creek

Whitewood

Spearfish

Saint

Onge

DEADWOOD

Lead

BELLE FOURCHE

Newell

STURGIS

Blackhawk

Piedmont

Tilford

Box Elder 

Hill City

Hermosa

CUSTER

HOT SPRINGS

Edgemont

Minnekahta

Tinton

Cheyenne

Crossing

Central

City

Roubaix

Nemo

Vale

Nisland

Hayward

Keystone

Rochford

Pringle

Fairburn

Buffalo Gap

Dewey

Cascade

Springs

Igloo

Provo

Oral

Rockerville

RAPID CITY

LIMESTONE PLATEAU

 Wind Cave

National Park

Jewel Cave

National

Monument

Mt. Rushmore

National

Memorial

CUSTER

STATE

PARK

Wind

Cave

Harney

Peak

x

Calamity

Peak

x

Iron

Mountain x

Onyx

Cave

Bear

x Butte

Ellsworth

Air Force

Base

BUTTE CO

LAWRENCE CO MEADE CO

PENNINGTON CO

CUSTER CO

FALL RIVER CO

WYOMING

SOUTH DAKOTA

3,000

4,000

4,000

3,000

3,000

5,000

5,000

3,000

6,000

3,000

7,000

3,000

3,000

5,000

5,000

7,000

7,000

7,000

7,000

5,000

6,000

6,000

4,000

6,000

6,000

5,000

4,000

4,000

4,000

3,000

3,000

4,000

5,000

20

18

15

16

18

28

26

20

17

17

19

19

20

21

21

22

22

23

23

24

24

27

25

25

20

18

18

19

19

20

17

17

16

0 10 20

0 10 20 MILES

KILOMETERS

LINE OF EQUAL PRECIPITA-

 TION--Number is average

 annual precipitation. Interval

 1 inch

LAND-SURFACE CONTOUR--

 Number is altitude above

 mean sea level. Contour

 interval 1,000 feet

OUTCROP OF MADISON LIME

 STONE (from Strobel and

 others, 1999)

OUTCROP OF MINNELUSA

 FORMATION (from Strobel

 and others, 1999)

EXPLANATION

104o 45' 103o

30'

15' 103o

30'

44o

45'

15'

44o

45'

30'

43o

15'

Base modified from U.S. Geological Survey digital data,

1:100,000, 1977, 1979, 1981, 1983, 1985

Rapid City, Office of City Engineer map, 1:18,000, 1996

Universal Transverse Mercator projection, zone 13
8 Hydrology of the Black Hills Area, South Dakota

Figure 5. Distribution of annual precipitation for the study area and counties within the study area, 

water years 1931-98 (modified from Driscoll and Carter, 2001). ANNUAL PRECIPITATION, IN INCHES

EXPLANATION

0

40

10

20

30

10th percentile

25th percentile

Median

75th percentile

90th percentile

Maximum

Minimum

Study area

Butte

Lawrence

Meade

Pennington

Custer

Fall River

Long-term average

 for study area

 (18.61 inches)

Figure 6. Distribution of monthly precipitation for the study area, water years 1931-98 (from 

Driscoll, Hamade, and Kenner, 2000).

OCT NOV DEC JAN FEB MAR APR MAY JUN JUL AUG SEP

0.01

100

0.02

0.05

0.1

0.2

0.5

1

2

5

10

20

50

PRECIPITATION, IN INCHES

EXPLANATION

10th percentile

Minimum

25th percentile

Median

75th percentile

90th percentile

Maximum
Climatic Framework 9

Figure 7. Mean monthly precipitation for study area and selected counties, water years 1931-98 (from Driscoll and 

Carter, 2001).

10

0.1

0.2

0.5

1

2

5

MEAN MONTHLY PRECIPITATION, IN INCHES

OCT NOV DEC JAN FEB MAR APR MAY JUN JUL AUG SEP

Lawrence County

Fall River County

Study area

Figure 8. Long-term trends in precipitation for the Black Hills area, water years 1931-98 (from Driscoll, Hamade, and 

Kenner, 2000).

0

30

10

20

ANNUAL PRECIPITATION,

IN INCHES

Annual precipitation

Long-term average

 (18.61 inches)

-10

10

-5

0

5

 ANNUAL DEPARTURE,

IN INCHES 

1930 1940 1950 1960 1970 1980 1990 2000

YEAR

-50

0

-40

-30

-20

-10

CUMULATIVE DEPARTURE,

IN INCHES

A Annual precipitation for the entire study area

B Annual departure from long-term average

C Cumulative departure from long-term average
10 Hydrology of the Black Hills Area, South Dakota

The long-term precipitation trends are especially 

important because of potential for bias in analysis and 

interpretation of available hydrologic data sets, which 

are much more abundant for the recent wet years. 

Water-level records are available for 71 observation 

wells in the Black Hills area for 1998, compared with 

five wells for 1965 (Driscoll, Bradford, and Moran, 

2000). Miller and Driscoll (1998) reported streamflow 

records for 65 gages for 1993, compared with 30 gages 

for 1960. Thus, the potential for bias is an important 

consideration in analysis of hydrologic data sets for the 

Black Hills area.

Average annual potential evaporation generally 

exceeds average annual precipitation throughout the 

study area. Thus, evapotranspiration generally is 

limited by precipitation amounts and availability of soil 

moisture. Average pan evaporation for April through 

October is about 30 inches at Pactola Reservoir 

and about 50 inches at Oral (U.S. Department of 

Commerce, 1999).

Geologic Framework

The stratigraphic and structural features in the 

Black Hills area are complex. Many of the geologic 

formations, such as the Deadwood Formation, Madison 

Limestone, Minnelusa Formation, Minnekahta Limestone, and Inyan Kara Group, in the Black Hills (fig. 9) 

are regionally extensive. Several formations thin or 

pinch out in southern and eastern South Dakota. To 

better understand the stratigraphic and structural settings in the Black Hills, an overview of the regional 

geologic setting is provided first and is followed by an 

overview of the local geologic setting.

Regional Geologic Setting

Parts of Montana, North Dakota, South Dakota, 

and Wyoming are included in the Northern Great Plains 

area. The present-day structural features (fig. 2) of the 

Northern Great Plains are directly related to the geologic history of the Cordilleran platform, which is a 

part of the stable interior of the North American Continent (Downey, 1986). The present-day structure probably was controlled by the pre-existing structural grain 

in the Precambrian basement and modified during the 

Laramide orogeny (Downey, 1984).

During Paleozoic time, the area generally was 

broad, flat, and covered by shallow, warm seas 

(Downey, 1984). Numerous disconformities during 

Paleozoic time indicate intermittent transgressions and 

regressions when seas advanced from west to east in 

response to tectonic activity of the Antler orogeny to 

the west (Sandberg and Poole, 1977). Deposits generally were beach, shallow marine, carbonate, sabkha, 

and evaporite units (Redden and Lisenbee, 1996). 

During Cretaceous time, the area was covered by 

a north-south trending sea, which extended from the 

Gulf of Mexico to the Arctic Ocean (Downey, 1986). 

During Late Cretaceous time, the sea was at its widest 

extent, but marine deposition was interrupted by frequent east-west regressions (Anna, 1986). 

Paleostructure

The Northern Great Plains area was part of the 

Cordilleran platform throughout most of Paleozoic 

time. The Williston Basin, which covers parts of North 

Dakota, South Dakota, southern Saskatchewan, southwestern Manitoba, and eastern Montana (fig. 10), 

began to take shape during Ordovician time (Carlson 

and Anderson, 1965). Other major Jurassic and Cretaceous (pre-Laramide) paleostructural elements 

(fig. 10) include the Powder River Basin, the Central 

Montana trough and uplift, the Cedar Creek anticline, 

and the Alberta shelf (Anna, 1986). 

The Laramide orogeny, which affected the 

eastern Rocky Mountains of the United States, began 

during late Cretaceous time and continued in the 

Eocene period (Redden and Lisenbee, 1996). The 

Laramide orogeny was characterized by large-scale 

warping, deep erosion of uplifts, and deposition of orogenic sediments into basins (Tweto, 1975). Most, if not 

all, pre-Laramide structural features (fig. 10) were 

reactivated and became more prominent during the 

Laramide orogeny (Anna, 1986). During the Laramide 

orogeny, the Bighorn and Laramie Mountains, the 

Black Hills, and the Central Montana uplift formed, 

and the Williston and Powder River Basins (fig. 2) 

were downwarped into essentially their present configuration (Anna, 1986).
Geologic Framework 11Figure 9. Stratigraphic section for the Black Hills.

STRATIGRAPHIC UNIT DESCRIPTION THICKNESS IN FEET

ABBREVIATION

FOR

STRATIGRAPHIC

INTERVAL

SYSTEM ERATHEM

QUATERNARY

& TERTIARY (?)

UNDIFFERENTIATED ALLUVIUM AND COLLUVIUM 0-50 Sand, gravel, boulder, and clay.

1,200-2,700

Light colored clays with sandstone channel fillings and local limestone lenses. WHITE RIVER GROUP Tw

TERTIARY

QTac

Principal horizon of limestone lenses giving teepee buttes. Dark-gray shale containing scattered concretions. Widely scattered limestone masses, giving small teepee buttes. Black fissile shale with concretions. 

PIERRE SHALENIOBRARA FORMATION 180-300 Impure chalk and calcareous shale.

CARLILE SHALE Turner Sandy Member

Wall Creek Member

1350-750 Light-gray shale with numerous large concretions and sandy layers.

Dark-gray shale

GRANEROS GROUP

GREENHORN FORMATION

Kps

225-380 Impure slabby limestone. Weathers buff.

Dark-gray calcareous shale, with thin Orman Lake limestone at base.

BELLE FOURCHE SHALE

MOWRY SHALE

MUDDY

SANDSTONE

NEWCASTLESANDSTONE

SKULL CREEK SHALE

150-850

Gray shale with scattered limestone concretions.Clay spur bentonite at base.

125-230

0-150

Light-gray siliceous shale. Fish scales and thin layers of bentonite.Brown to light-yellow and white sandstone.

150-270 Dark-gray to black siliceous shale.

CRETACEOUS

FALL RIVER FORMATION

LAKOTA

FM

INYAN KARA

GROUPFuson Shale Minnewaste Limestone Chilson Member

10-200 Massive to thin-bedded, brown to reddish-brown sandstone.

Yellow, brown, and reddish brown massive to thinly bedded sandstone, pebble conglomerate, siltstone, and claystone. Local fine-grained limestone and coal.

10-190

0-25

25-485

0-2200-225

Green to maroon shale. Thin sandstone.Massive fine-grained sandstone.

250-450

0-45

Greenish-gray shale, thin limestone lenses.Glauconitic sandstone; red sandstone near middle.Red siltstone, gypsum, and limestone.

MORRISON FORMATION

UNKPAPA SS Redwater Member

Lak MemberHulett MemberStockade Beaver Mem.Canyon Spr Member

SUNDANCEFORMATIONGYPSUM SPRING FORMATION

Kik

Ju JURASSIC

Goose Egg Equivalent

SPEARFISH FORMATION T Ps R TRIASSIC

MINNEKAHTA LIMESTONEOPECHE SHALE Po

Pmk

375-800

125-65

Red silty shale, soft red sandstone and siltstone with gypsum and thin limestone layers.Gypsum locally near the base.Thin to medium-bedded, fine-grained, purplish gray laminated limestone.Red shale and sandstone. 125-150

1375-1,175

1<200-1,000

30-60

10-23510-15010-500

Yellow to red cross-bedded sandstone, limestone, and anhydrite locally at top.Red shale with interbedded limestone and sandstone at base.Massive light-colored limestone. Dolomite in part. Cavernous in upper part.Pink to buff limestone. Shale locally at base.Buff dolomite and limestone.Green shale with siltstone.Massive to thin-bedded buff to purple sandstone. Greenish glauconitic shale flaggy dolomite and flat-pebble limestone conglomerate. Sandstone, with conglomerate locally at the base.Schist, slate, quartzite, and arkosic grit. Intruded by diorite, metamorphosed to amphibolite, and by granite and pegmatite.

PERMIAN

PENNSYLVANIAN

MISSISSIPPIAN

P Pm MINNELUSA FORMATION

MADISON (PAHASAPA) LIMESTONEENGLEWOOD FORMATION

MDme

Ou

DEVONIAN

WHITEWOOD (RED RIVER) FORMATIONWINNIPEG FORMATIONDEADWOOD FORMATIONUNDIFFERENTIATED IGNEOUSAND METAMORPHIC ROCKS

OCd

pCu

ORDOVICIAN

CAMBRIAN

PALEOZOIC MESOZOIC CENOZOIC

PRECAMBRIAN

Modified from information furnished by the Department of Geology and Geological Engineering,

South Dakota School of Mines and Technology (written commun., January 1994)

0-300

Includes rhyolite, latite, trachyte, and phonolite. INTRUSIVE IGNEOUS ROCKS Tui --

1Modified based on drill-hole data

Interbedded sandstone, limestone, dolomite, shale, and anhydrite.
12 Hydrology of the Black Hills Area, South Dakota

Figure 10. Regional paleostructure during Jurassic and Cretaceous time in the western interior of the United States 

(modified from Anna, 1986).

100 400 200 300

0

0

100 300 400 200 MILES

KILOMETERS

Base from U.S. National Atlas

1:17,000,000, 1970
Geologic Framework 13

Stratigraphy

Precambrian rocks form the basement in the 

northern Great Plains area. Precambrian rocks are 

exposed in the central core of many of the mountain 

ranges, but lie greater than 15,000 ft below land surface 

at the center of the Williston Basin (Downey and 

Dinwiddie, 1988). 

Rocks of Cambrian and Ordovician age consist 

of sandstone, shale, limestone, and dolomite and represent the shoreward facies of a transgressive sea 

(Peterson, 1981). The extent of the Cambrian and 

Ordovician rocks in the northern Great Plains area is 

shown in figure 11. The principal geologic units of 

Cambrian and Ordovician age are the Deadwood 

Formation, Emerson Formation, Winnipeg Formation, 

Red River Formation (Whitewood Formation), and 

Stony Mountain Formation (fig. 12). Rocks of Cambrian and Ordovician age extend into Canada where 

they are exposed along the Precambrian shield 

(Downey, 1986). Erosion during Devonian time truncated the Ordovician geologic units in South Dakota 

and Wyoming to the south of a line extending between 

the central Black Hills and southern Bighorn Mountains (Peterson, 1981). Rocks of Silurian age are not 

present in the Black Hills area. 

The extent of Mississippian rocks in the northern 

Great Plains area is shown in figure 11. These rocks 

overlying the Bakken Formation (where present) are 

termed the Madison Limestone, or Madison Group 

where divided (fig. 12). The Madison Limestone consists of a sequence of marine carbonates and evaporites 

deposited mainly in a warm, shallow-water environment (Downey, 1986). Development of karst (solution) 

features in the Madison Limestone was common 

because the carbonate rocks are relatively soluble in 

water (Downey, 1986). Complex and interconnected 

solution features developed in the Madison Limestone 

during tropical conditions when it was exposed at or 

near land surface (Busby and others, 1995). Large and 

extensive cave systems have formed in the outcrop 

areas of the Madison Limestone in the Bighorn 

Mountains and in the Black Hills.

Rocks of Pennsylvanian age consist primarily of 

marine sandstone, shale, siltstone, and carbonate. The 

Pennsylvanian rocks are divided into many different 

geologic units (fig. 12). Rocks of Pennsylvanian-age 

have been truncated by pre-Jurassic erosion progressively northward across central Montana; these rocks 

thin to zero thickness near the axis of the central 

Montana trough (Downey, 1986; figs. 10 and 11).

A sequence of red shale, siltstone, and evaporite 

deposits belonging to the upper part of the Goose Egg 

and Spearfish Formations of Triassic age overlie the 

Minnelusa Formation (Downey and Dinwiddie, 1988). 

Jurassic rocks, which include the Nesson, Piper, 

Rierdon, and Sundance Formations and their equivalents (fig. 12) are predominantly carbonate, shale, and 

calcareous shale (Anna, 1986). 

Deposits during Cretaceous time primarily were 

sandstones, shales, and minor carbonates (Redden and 

Lisenbee, 1996). A number of formation names have 

been applied to the various Cretaceous units in the 

northern Great Plains area; however, in several 

instances, these formation names are used only in one 

State or subregion (fig. 13). Lower Cretaceous rocks 

(fig. 13) range in thickness from zero in eastern North 

Dakota and South Dakota to more than 1,400 ft in westcentral Wyoming (Anna, 1986). The extent of the 

Lower Cretaceous sandstones, which include the Inyan 

Kara Group, Muddy Sandstone, and Newcastle or 

Dakota Sandstone, is shown in figure 11. The sedimentary pattern of Upper Cretaceous rocks (fig. 13) is associated with four main transgressions and regressions of 

shallow seas.

Tertiary units (fig. 13) generally were deposited 

in a continental environment (Downey, 1986). Deposits 

of Quaternary age in the northern Great Plains area 

consist of alluvium, glacial materials, and other surficial deposits. Alluvial deposits fill major drainages in 

the area. Glacial deposits are located only in the eastern 

parts of North Dakota and South Dakota and in the 

northernmost part of Montana (Downey, 1986).

Local Geologic Setting

The Black Hills uplift is a northwest-trending, 

asymmetric, elongate dome, or doubly plunging anticline. Uplift began about 62 million years ago during 

the Laramide orogeny and probably continued in the 

Eocene period (Redden and Lisenbee, 1996). Large 

anticlines occur on the northern and southern flanks of 

the Black Hills and plunge away from the uplift into the 

surrounding plains. Numerous smaller folds, faults, 

domes, and monoclines also occur in the Black Hills 

(fig. 14). Igneous intrusions were emplaced on the 

northern flanks of the uplift during the Tertiary Period.
14 Hydrology of the Black Hills Area, South Dakota

Figure 11. Approximate extent of rocks in the northern Great Plains area for selected geologic periods.

100o 105o 110o

115o

48o

43o

100o 105o 110o

115o

48o

43o

100o 105o 110o

115o

48o

43o

100o 105o 110o

115o

48o

43

Base modified from U.S. GeologicalSurvey digital data, 1:2,000,000, 1972

o

Base modified from U.S. GeologicalSurvey digital data, 1:2,000,000, 1972

0 50 100 MILES

0 50 100 KILOMETERS

Base modified from U.S. GeologicalSurvey digital data, 1:2,000,000, 1972

Base modified from U.S. GeologicalSurvey digital data, 1:2,000,000, 1972

0 50 100 MILES

0 50 100 KILOMETERS

0 50 100 MILES

0 50 100 KILOMETERS

0 50 100 MILES

0 50 100 KILOMETERS

● Casper

★ Cheyenne

●

★

Grand Forks

Bismarck

●

●

●

●

●

●

★

★

Helena

Great Falls

Butte

Billings

Rapid City

Pierre

Sioux

Falls

Fargo

● Casper

★ Cheyenne

●

★

Grand Forks

Bismarck

●

●

●

●

●

●

★

★

Helena

Great Falls

Butte

Billings

Rapid City

Pierre

Sioux

Falls

Fargo

Casper

Cheyenne

Grand Forks

Bismarck Helena

Great Falls

Butte

Billings

Rapid City

Pierre

Sioux

Falls

Fargo

Casper

Cheyenne

Grand Forks

Bismarck Helena

Great Falls

Butte

Billings

Rapid City

Pierre

Sioux

Falls

Fargo

●

★

●

●

●

●

●

★

★

●

●

●

★

●

★

●

●

●

●

●

●

★

★

★

N O R T H D A K O T A

M O N T A N A

S O U T H D A K O T A

W Y O M I N G

N O R T H D A K O T A

M O N T A N A

S O U T H D A K O T A

W Y O M I N G

N O R T H D A K O T A

M O N T A N A

S O U T H D A K O T A

W Y O M I N G

N O R T H D A K O T A

M O N T A N A

S O U T H D A K O T A

W Y O M I N G

Cambrian and Ordovician-age rocks

Pennsylvanian-age rocks

Modified from Downey and Dinwiddie,

1988; Whitehead, 1996

Cretaceous-age rocks

Modified from Downey and Dinwiddie,

1988; Whitehead, 1996

Mississippian-age rocks

Modified from Downey and Dinwiddie,

1988; Whitehead, 1996

Modified from Downey and Dinwiddie, 1988
Geologic Framework 15

Figure 12. Generalized correlation chart for Paleozoic-age rocks in Montana, North Dakota, South Dakota, and Wyoming 

(modified from Downey, 1986).

Series

UPPER PERMIAN

LOWER PERMIAN

UPPER

PENNSYLVANIAN

UPPER

MISSISSIPPIAN

UPPER

DEVONIAN

MIDDLE

DEVONIAN

UPPER

ORDOVICIAN

MIDDLE

ORDOVICIAN

LOWER

ORDOVICIAN

UPPER

CAMBRIAN

MIDDLE

CAMBRIAN

LOWER

CAMBRIAN

PRECAMBRIAN

LOWER DEVONIAN

UPPER SILURIAN

MIDDLE SILURIAN

LOWER SILURIAN

LOWER

MISSISSIPPIAN

MIDDLE

PENNSYLVANIAN

LOWER

PENNSYLVANIAN

MIDDLE JURASSIC Piper Formation

Goose Egg Formation

Madison Limestone

Three Forks Formation

Jefferson Formation

Interlake Formation

Red River Formation Bighorn

Dolomite

Snowy Range

Formation or

Gallatin and

Gros Ventre

Formations

or equivalents

Red River Formation

or

Whitewood Dolomite

Bighorn Dolomite

Winnipeg Formation

Deadwood Formation

Deadwood Formation Emerson Formation Emerson Formation

Flathead Sandstone Flathead Sandstone

Winnipeg Formation Winnipeg Formation Winnipeg Formation

Red River Formation

Stony Mountain Formation

Red River Formation Red River Formation

Winnipeg Formation

Deadwood

Formation

Snowy Range

Formation or

Gallatin and

Gros Ventre

Formations

or equivalents

Deadwood

Formation

Stony Mountain

Formation

Flathead

Sandstone

Flathead

Sandstone

Interlake Formation

Jefferson Formation

Three Forks Formation Three Forks Formation

Birdbear Formation

Duperow Formation

Souris River Formation

Dawson Bay Formation

Prairie Formation

Winnipegosis Formation

Souris River Formation

Duperow Formation

Birdbear Formation

Three Forks Formation

Jefferson Formation

Three Forks Formation

Madison Limestone

or

Pahasapa Limestone Madison Group Madison Group

Englewood Formation Bakken Formation Bakken Formation Bakken Formation

Charles

Formation

Mission Canyon

Limestone

Lodgepole

Limestone

Charles

Formation

Mission Canyon

Limestone

Lodgepole

Limestone

Madison Group

Madison Group

Charles

Formation

Mission Canyon

Limestone

Lodgepole

Limestone

Mission Canyon

Limestone

Lodgepole

Limestone

Tensleep

Sandstone Tensleep Sandstone Tensleep Sandstone

Amsden

Formation Amsden Formation

Minnelusa

Formation Minnelusa Formation

Minnelusa Formation

Tyler Formation

Amsden Group

(upper part)

Amsden Group

(upper part)

Tyler Formation

of Amsden Group

Heath Formation

Otter Formation

Kibbey Formation

Big Snowy

Group

Heath Formation

Otter Formation

Kibbey Formation

Big Snowy

Group

Piper Formation

Chugwater Formation Chugwater Formation

Gypsum Spring Formation Piper Formation Piper Formation Piper Formation

Spearfish Formation

Minnekahta Limestone

Opeche Shale

Minnekahta Limestone

Opeche Shale

Spearfish Formation

JURASSIC

TRIASSICSYSTEM PERMIAN PENNSYLVANIAN MISSISSIPPIAN DEVONIAN SILURIAN ORDOVICIAN CAMBRIAN

Powder River Basin South-Central

Montana

Western

South Dakota

Central

Montana Trough

North-Central

Montana Williston Basin
16 Hydrology of the Black Hills Area, South Dakota

Figure 13. Generalized correlation chart for Mesozoic- and Cenozoic-age rocks in Montana, North Dakota,

South Dakota, and Wyoming (modified from Downey, 1986).

System

Series and

European

Stage

Black Hills--

South Dakota

Western

Montana

Central

Montana

Western Powder

River Basin--

Wyoming

Eastern Montana

--

Western

North Dakota

Eastern

North Dakota

--

Eastern

South Dakota

PLIOCENE

MIOCENE

OLIGOCENE

EOCENE

PALEOCENE

MAESTRICHTIAN

CAMPANIAN

UPPER CRETACEOUS LOWER CRETACEOUS UPPER JURASSIC MIDDLE JURASSIC

SANTONIAN

CONIACIAN

TURONIAN

CENOMANIAN

ALBIAN

APTIAN

NECOMIAN

TITHONIAN

KIMMERIDGIAN

OXFORDIAN

CALLOVIAN

BATHONIAN

BAJOCIAN

Ogallala Fm.

Arikaree Fm.

White River

White River Fm. Fm.

Willow Creek

Fm.

St. Mary River

Fm.

Bearpaw Sh.

Two Medicine Fm.

Telegraph Creek Fm.

Marias River

Shale

Bootlegger Mbr.

Taft Hill Mbr.

Flood Mbr.

Sunburst Mbr.

Morrison Fm. Morrison Fm. Morrison Fm.

Upper part

Lower part

Sundance Fm.Sundance Fm.

Upper part

Lower part

Morrison Fm. Morrison Fm.

Swift Fm.

Rierdon Fm. Rierdon Fm. Rierdon Fm.

Rierdon Fm.

Piper Fm.

Piper Fm.

Nesson Fm. Gypsum Spring Fm. Gypsum Spring Fm. Nesson Fm.

Sawtooth Fm. Piper Fm.

Swift Fm. Swift Fm.

Swift Fm.

Fuson equivalent

Lakota equivalent

Fuson Mbr.

Lakota Mbr.

Fuson Mbr.

Lakota Mbr.

Fuson Mbr.

Lakota Mbr.

Cutbank Ss.

Mbr.

Telegraph Creek Fm.

Niobrara Fm.

Belle Fourche Sh.

Frontier Fm.

*Bowdoin ss.

Niobrara Fm.

Carlile Sh. Carlile Sh.

Greenhorn Fm. Greenhorn Fm.

Belle Fourche Sh. Belle Fourche Sh. Belle Fourche Sh.

Mowry Sh. Mowry Sh. Mowry Sh. Mowry Sh. Mowry Sh.

Muddy Ss. Muddy Ss. Newcastle Ss. Muddy Ss. Newcastle Ss.

Skull Creek Sh.

*First Cat Creek ss. Fall River equivalent Fall River Ss. Fall River Ss. Fall River Ss.

*Second Cat Creek ss.

*Third Cat Creek ss.

Skull Creek Sh. Skull Creek Sh. Skull Creek Sh.

*Basal silt *Basal silt *Basal silt *Basal silt

Skull Creek or

Thermopolis Sh.

Greenhorn Fm. Greenhorn Fm.

Carlile Sh.

Niobrara Fm. Niobrara Fm.

Niobrara Mbr.

Cody Sh.

Inyan Kara Gp.

Blackleaf Fm. Kootenai Fm.

Kootenai

Fm. Bearpaw Shale

Judith River Fm.

Pierre Shale Pierre Shale

Pierre Shale

Lewis Shale

Hell Creek Fm.

Fox Hills Ss.

Claggett Sh.

Mosby Ss. Mbr.

Eagle Ss.

Fox Hills Ss.

Teapot Ss. Mbr.

Carlile equivalent

Unnamed

Sussex Ss. Mbr.

Shannon Ss. Mbr.

Carlile

Sh.

Vaughn

Mbr.

*Bow

Island ss.

Mitten Black Sh. Mbr. Pembina Mbr. Sharon Springs Mbr.

Fishtooth ss.*

Mesa

Verde

Fm.

Cody Sh. or

Steele Sh.

Unnamed

Parkman Ss. Mbr.

Fox Hills Ss. Fox Hills Ss.

Horsethief Ss.

Virgelle Ss.

Hell Creek Fm. Hell Creek Fm. Lance Fm.

Wasatch Fm.

Tongue River Mbr. Tongue River Mbr. Tongue River Mbr. Sentinel Butte Mbr.

Tongue River Mbr.

Lebo Shale Mbr. Lebo Shale Mbr. Lebo Shale Mbr.

Dakota

Ss./Fm.

(part)

Cannonball Mbr.

Cannonball Mbr.

Tullock Mbr. Tullock Mbr. Ludlow Mbr. Ludlow Mbr.

Volcanic rocks Fort Union Fm.

Fort Union Fm.Fort Union Fm.Fort Union Fm.

Volcanic rocks

White River

Fm. Western

North Dakota

Only

Golden Valley

Fm. Western

North Dakota

Only

TERTIARY CRETACEOUS JURASSIC

?

?? ? ? ?

* Of informal or subsurface usage
Geologic Framework 17

Figure 14. Distribution of hydrogeologic units in the Black Hills area (modified from Strobel and others, 1999).

Bear Gulch

Beaver Creek

Redbird

Gillette

Boles

Canyon

Canyon

Canyon

Cold Spring

C s

reek

Hot Brook Canyon

Creek Spokane

Victoria Creek

LIMESTONE PLATEAU

Whitewood

Spearfish

Saint

Onge

DEADWOOD

Lead

BELLE FOURCHE

Newell

STURGIS

Blackhawk

Piedmont

Tilford

Box Elder 

Hill City

Hermosa

CUSTER

HOT SPRINGS

Edgemont

Minnekahta

Tinton Central

City

Roubaix

Nemo

Vale

Nisland

Hayward

Keystone

Rochford

Pringle

Fairburn

Buffalo Gap

Dewey

Cascade

Springs

Igloo

Provo

Oral

Rockerville

Belle Fourche

Reservoir Horse

Indian

Creek

Creek

Creek

Creek

Creek

Creek

Creek

Creek

Creek

Alkali

Creek

Antelope

Creek

Creek

Creek

Creek

Creek

Battle

Creek

Creek

Creek

Canyon

Horsehead

Fall River

Cr

Lame

Johnny

Red

Creek

Creek

Hat

Hay

Hell

Beaver

Spring

Spring

Creek

Rapid

Rapid

Castle

Creek

Boxelder

Creek

Bear

Elk

Butte

False

Bottom

Spearfish

BELLE

RIVER

Owl

F OURCHE

Hay

Redwater River

Canyon

Canyon

Cottonwood

Whitewood

Pactola

Reservoir

Deerfield

Reservoir

Sheridan

Lake

Coolidge

Cr

Grace

French

Creek

Angostura

Reservoir

CHEYENNE

RIVER

RIVER

CHEYENNE

N. Fork Rapid Cr

Rhoads Fork

Castl e Cr

Bear

Gulch

Creek

Crow

Cox

Lake

Cr

Little Spearfish

S. Fork

S. Fork Rapid Cr

Beaver

Creek

Whitetail

Cr

Cr Cr

Annie

Squaw

Meadow Cr

Elk

Little

Creek

Ellsworth

Air Force

Base

Wind Cave

National Park

Jewel Cave

National

Monument

Mt. Rushmore

National

Memorial

CUSTER

STATE

PARK

Wind

Cave

Harney

Peak x

Terry

Peak

Crooks

Towerx

x

BUTTE CO

LAWRENCE CO MEADE CO

PENNINGTON CO

CUSTER CO

FALL RIVER CO

WYOMING

SOUTH DAKOTA

QTac

Tw

Tui

Kps

Ju

TRPs

MDme

Kik

Pmk

Po

Ou

PPm

OCd

pCu

A

A'

0 10 20

0 10 20 MILES

KILOMETERS

EXPLANATION

Alluvium and colluvium,

 undifferentiated

Unconsolidated

units

White River aquifer

Minnekahta aquifer

Minnelusa aquifer

Madison aquifer

Deadwood aquifer

Inyan Kara aquifer

Tertiary intrusive

units

Spearfish confining

unit

Opeche confining

unit

Cretaceoussequence

confining unit

Jurassic-sequence

semiconfining unit

Ordovician-sequence

semiconfining unit

Precambrian igneous and

metamorphic units

White River Group

Undifferentiated intrusive

 igneous rocks

Pierre Shale to Skull Creek Shale,

 undifferentiated

Inyan Kara Group

Morrison Formation to Sundance

 Formation, undifferentiated

Spearfish Formation

Minnekahta Limestone

Opeche Shale

Minnelusa Formation

Madison (Pahasapa) Limestone

 and Englewood Formation

Whitewood Formation and

 Winnipeg Formation

Deadwood Formation

Undifferentiated igneous

 and metamorphic rocks

Stratigraphic

Units Map Units HydrogeologicUnits

A A' LINE OF GEOLOGIC SECTION

FAULT--Dashed where approximated.

 Bar and ball on downthrown side

ANTICLINE--Showing trace of axial

 plane and direction of plunge.

 Dashed where approximated

SYNCLINE--Showing trace of axial plane

 and direction of plunge. Dashed

 where approximated

MONOCLINE--Showing trace of axial

 plane. Dashed where approximated

DOME--Symbol size approximately pro-

 portional to size of dome. Dome

 asymmetry indicated by arrow length

104o 45' 103o

30'

15' 103o

30'

44o

45'

15'

44o

45'

30'

43o

15'

Base modified from U.S. Geological Survey digital data,

1:100,000, 1977, 1979, 1981, 1983, 1985

Rapid City, Office of City Engineer map, 1:18,000, 1996

Universal Transverse Mercator projection, zone 13
18 Hydrology of the Black Hills Area, South Dakota

The oldest stratigraphic units in the study area 

are the Precambrian igneous and metamorphic rocks 

(fig. 9), which underlie the Paleozoic, Mesozoic, and 

Cenozoic rocks and sediments. These Precambrian 

rocks range in age from 1.7 to about 2.5 billion years 

and were eroded to a gentle undulating plain at the 

beginning of the Paleozoic Era (Gries, 1996). The Precambrian rocks are highly variable in composition and 

are composed mostly of metasediments, such as schists 

and graywackes. The Paleozoic and Mesozoic rocks 

were deposited on the Precambrian rocks as nearly horizontal beds. Subsequent uplift during the Laramide 

orogeny and related erosion exposed the Precambrian 

rocks in the central core of the Black Hills, with many 

of the Paleozoic and Mesozoic sedimentary rocks 

exposed in roughly concentric rings around the core. 

The exposed Precambrian rocks commonly are referred 

to as the crystalline core.

The layered series of sedimentary rocks surrounding the crystalline core includes outcrops of the 

Madison Limestone (also locally known as the 

Pahasapa Limestone) and the Minnelusa Formation. 

The bedrock sedimentary formations typically dip 

away from the uplifted Black Hills (fig. 15) at angles 

that can approach or exceed 15 to 20 degrees near the 

outcrops, and decrease with distance from the uplift to 

less than 1 degree (Carter and Redden, 1999a, 1999b, 

1999c, 1999d, 1999e). Following are descriptions for 

the bedrock formations that contain major aquifers in 

the Black Hills area.

The oldest sedimentary unit in the study area is 

the Cambrian- and Ordovician-age Deadwood Formation, which is composed primarily of brown to lightgray glauconitic sandstone, shale, limestone, and local 

basal conglomerate (Strobel and others, 1999). These 

sediments were deposited on top of a generally horizontal plain of Precambrian rocks in a coastal- to nearshore environment (Gries, 1975). The thickness of the 

Deadwood Formation increases from south to north in 

the study area and ranges from 0 to 500 ft (Carter and 

Redden, 1999e). In the northern and central Black 

Hills, the Deadwood Formation is disconformably 

overlain by Ordovician rocks, which include the 

Whitewood and Winnipeg Formations. The Winnipeg 

Formation is absent in the southern Black Hills, and the 

Whitewood Formation has eroded to the south and is 

not present south of the approximate latitude of Nemo 

(DeWitt and others, 1986). In the southern Black Hills, 

the Deadwood Formation is unconformably overlain by 

the Devonian- and Mississippian-age Englewood Formation because of the absence of the Ordovician 

sequence. The Englewood Formation is overlain by the 

Madison Limestone.

The Mississippian-age Madison Limestone is a 

massive, gray to buff limestone that is locally dolomitic 

(Strobel and others, 1999). The Madison Limestone, 

which was deposited as a marine carbonate, was 

exposed at land surface for approximately 50 million 

years. During this period, significant erosion, soil 

development, and karstification occurred (Gries, 1996). 

There are numerous caves and fractures within the 

upper part of the formation (Peter, 1985). The thickness 

of the Madison Limestone increases from south to 

north in the study area and ranges from almost zero in 

the southeast corner of the study area (Rahn, 1985) to 

1,000 ft east of Belle Fourche (Carter and Redden, 

1999d). Because the Madison Limestone was exposed 

to erosion and karstification for millions of years, its 

contact with the overlying Minnelusa Formation is 

unconformable.

The Pennsylvanian- and Permian-age Minnelusa 

Formation consists mostly of yellow to red crossstratified sandstone, limestone, dolomite, and shale 

(Strobel and others, 1999). In addition to sandstone and 

dolomite, the middle part of the formation consists of 

shale and anhydrite (DeWitt and others, 1986). The 

upper part of the Minnelusa Formation also may contain anhydrite, which generally has been removed by 

dissolution in or near the outcrop areas, occasionally 

forming collapse features filled with breccia (Braddock, 1963). The Minnelusa Formation was deposited 

in a coastal environment, and dune structures at the top 

of the formation may represent beach sediments (Gries, 

1996). The thickness of the Minnelusa Formation 

increases from north to south and ranges from 375 ft 

near Belle Fourche to 1,175 ft near Edgemont in the 

study area (Carter and Redden, 1999c). In the northeastern part of the central Black Hills, little anhydrite 

occurs in the subsurface due to a change in the depositional environment. On the south and southwest side of 

the study area, the thickness of clastic units increases 

and a thick section of anhydrite occurs. In the southern 

Black Hills, the upper part of the Minnelusa Formation 

thins due to leaching of anhydrite. The Minnelusa 

Formation is disconformably overlain by the Permianage Opeche Shale, which is overlain by the Minnekahta 

Limestone.
Geologic Framework 19

Figure 15. Geologic cross section A-A′ (modified from Strobel and others, 1999). Location of section is shown in figure 14. Abbreviations for stratigraphic intervalsare explained in figure 9.

SEA

6,0005,0004,0003,0002,0001,000

LEVEL

SEA

FEET

7,0006,0005,0004,0003,0002,0001,000

LEVEL

A A'

FEET

7,000

MDme

MDme

Kps

Ju

Kik

PPm

PPm

OCd

OCd Pmk

Po QTac QTac

Rapid Creek Rapid Creek

South Fork Castle Creek

South Fork Castle Creek

Rapid Creek

Rapid Creek

Rapid City

Rapid Creek

VERTICAL EXAGGERATION X5

T Ps R

SOUTH DAKOTA

WYOMING

pCu pCu

LIMESTONE PLATEAU

4 6 2 8 10

00

4 2 6 8 10 MILES

KILOMETERS
20 Hydrology of the Black Hills Area, South Dakota

The Permian-age Minnekahta Limestone is a 

fine-grained, purple to gray laminated limestone 

(Strobel and others, 1999), which ranges in thickness 

from 25 to 65 ft in the study area. The Minnekahta 

Limestone is overlain by the Triassic- and Permian-age 

Spearfish Formation.

The Cretaceous-age Inyan Kara Group consists 

of the Lakota Formation and overlying Fall River 

Formation. The Lakota Formation consists of the 

Chilson, Minnewaste Limestone, and Fuson Shale 

members. The Lakota Formation consists of yellow, 

brown, and reddish-brown massive to thinly bedded 

sandstone, pebble conglomerate, siltstone, and claystone of fluvial origin (Gott and others, 1974); locally 

there are lenses of limestone and coal. The Fall River 

Formation is a brown to reddish-brown, fine-grained 

sandstone, thin bedded at the top and massive at the 

bottom (Strobel and others, 1999). The thickness of the 

Inyan Kara Group ranges from 135 to 900 ft in the 

study area (Carter and Redden, 1999a).

Ground-Water Framework

The hydrogeologic setting of the Black Hills area 

is schematically illustrated in figure 16, and the areal 

distribution of the hydrogeologic units is shown in 

figure 14. Four of the major aquifers in the Black Hills 

area (Deadwood, Madison, Minnelusa, and Inyan Kara 

aquifers) are regionally extensive and are discussed in 

the following sections in the context of regional and 

local hydrologic settings. A fifth major aquifer 

(Minnekahta aquifer) generally is used only locally, as 

are aquifers in the igneous and metamorphic rocks 

within the crystalline core area and in alluvium. In 

some local areas, wells are completed in strata that 

generally are considered to be semiconfining and 

confining units.

Regional Aquifers

The major aquifers underlie parts of Montana, 

North Dakota, South Dakota, Wyoming, and Canada. 

The parts of the regional aquifers in Canada are not 

described or shown in this report. 

The Paleozoic aquifers include the CambrianOrdovician aquifer (Deadwood aquifer in the Black 

Hills), Mississippian aquifer (Madison aquifer in 

the Black Hills), and the Pennsylvanian aquifer 

(Minnelusa aquifer in the Black Hills). Recharge to the 

Paleozoic aquifers occurs in high-altitude outcrop areas 

around the major uplifts such as the Black Hills uplift 

(fig. 17). 

The Cambrian-Ordovician (or Deadwood) 

aquifer is contained within the sandstones of Cambrian 

age (Deadwood Formation and equivalents) and limestones of Ordovician age (Red River Formation and 

equivalents) (fig. 12). Generally, flow in the CambrianOrdovician aquifer is from the high-altitude recharge 

areas to the northeast. Discharge (fig. 17) from the 

Cambrian-Ordovician aquifer is to adjacent aquifers, 

lakes and springs in eastern North Dakota, and springs 

and seeps where the aquifer crops out in Canada 

(Downey, 1984). Within the Great Plains region, the 

Cambrian-Ordovician aquifer contains fresh water 

(dissolved solids concentrations less than 1,000 mg/L 

(milligrams per liter)) only in an area surrounding the 

Black Hills and in a small area in north-central Wyoming (Whitehead, 1996). The aquifer is a brine (dissolved solids concentration greater than 35,000 mg/L) 

in eastern Montana and western and central North 

Dakota (Whitehead, 1996).

The Mississippian (or Madison) aquifer is contained within the limestones, siltstones, sandstones, 

and dolomite of the Madison Limestone or Group. 

Generally, water in the Mississippian aquifer is confined except in outcrop areas. Flow in the Mississippian 

aquifer generally is from the recharge areas to the 

northeast. Discharge (fig. 17) from the Mississippian 

aquifer occurs by upward leakage to the lower Cretaceous aquifer in central South Dakota and eastern flow 

to the Cambrian-Ordovician aquifer in eastern North 

Dakota (Downey, 1984). Water in the Mississippian 

aquifer is fresh only in small areas near recharge areas 

and becomes saline to slightly saline as it moves downgradient. The water is a brine with dissolved solids concentrations greater than 300,000 mg/L in the deep parts 

of the Williston Basin (Whitehead, 1996).

The Pennsylvanian (or Minnelusa) aquifer is 

contained within the sandstones and limestones of the 

Minnelusa Formation, Tensleep Sandstone, Amsden 

Formation, and equivalents of Pennsylvanian age 

(fig. 12). Water in the Pennsylvanian aquifer moves 

from recharge areas to the northeast to discharge areas 

in eastern South Dakota (Downey and Dinwiddie, 

1988). Some water discharges by upward leakage to the 

lower Cretaceous aquifer (Swenson, 1968, Gott and 

others, 1974).
Ground-Water Framework 21 Figure 16. Schematic showing simplified hydrogeologic setting of the Black Hills area. Schematic generally corresponds with geologic cross section shown in figure 15. Components considered for hydrologic budget of the Madison aquifer also are shown with inflow components shown in green and outflow components shown in blue.

Springconduit

Water

table

Cave

Flowing well

LIMESTONE PLATEAU

Deadwood

Madison

Inyan Kara Group Formation

Limestone

Precambrian igneousand metamorphic rocks

L mi estone

Minnekahta Minnelusa

Madison

Limestone

Formation

Fo mr ation

Deadwood

MinnelusaFormation

Alluvialaquifer

Potentiometricsurface ofMadisonaquifer

Leakage from/leakage to

Recharge

Lateral

ground-water

inflow

Artesian

springflow

Lateral

ground-water

outflow

Headwater

springflow MAJOR AQUIFER

CONFINING UNITSPRING

EXPLANATION

Dip of sedimentary rocks exaggeratedRelative thickness NOT TO SCALE
22 Hydrology of the Black Hills Area, South Dakota

Figure 17. General direction of ground-water flow in regional aquifer system within Paleozoic aquifer units (modified from Downey and Dinwiddie, 1988; Whitehead, 1996).

Base modified from U.S. GeologicalSurvey digital data, 1:2,000,000, 1972

0 50 100 MILES

0 50 100 KILOMETERS

●

★

●

★

●

●

●

●

●

●

★

★

Casper

Cheyenne

Grand Forks

Bismarck Helena

Great Falls

Butte

Billings

Rapid City

Pierre

Sioux

Falls

Fargo

100o 105o 110o

115o

48o

43o

N O R T H D A K O T A

M O N T A N A

S O U T H D A K O T A

W Y O M I N G

RECHARGE AREADISCHARGE AREA FOR MADISON AND MINNELUSA AQUIFERS (via adjacent aquifers)DISCHARGE AREA FOR DEADWOOD AQUIFER (via adjacent aquifers, springs, and seeps)EXTENT OF GROUND WATER WITH DISSOLVED SOLIDS CONCENTRATION GREATER THAN 100,000 MILLIGRAMS PER LITEREASTERN LIMIT OF DEADWOOD AQUIFER--Dashed where approximately locatedDIRECTION OF GROUND-WATER FLOW

EXPLANATION

Approximate Boundary of

Williston Basin
Ground-Water Framework 23

Several sandstone units (fig. 13) compose the 

lower Cretaceous aquifer, which is known as the Inyan 

Kara aquifer in South Dakota. Generally, water in the 

lower Cretaceous aquifer is confined by several thick 

shale layers except in aquifer outcrop areas around 

structural uplifts, such as the Black Hills. Water in the 

lower Cretaceous aquifer generally moves northeasterly from high-altitude recharge areas to discharge 

areas in eastern North Dakota and South Dakota 

(Whitehead, 1996). Although the aquifer is widespread, it contains little fresh water. Water is fresh only 

in small areas in central and south-central Montana and 

north and east of the Black Hills uplift (Whitehead, 

1996). More than one-half of the water in the lower 

Cretaceous aquifer is moderately saline, and the water 

is very saline or a brine in the deep parts of the Williston and Powder River Basins (Whitehead, 1996). 

Much of the saline water is believed to be from upward 

leakage of mineralized water from the Paleozoic 

aquifers.

Local Aquifers

Many of the sedimentary units contain aquifers, 

both within and beyond the study area. Within the 

Paleozoic rock interval, aquifers in the Deadwood 

Formation, Madison Limestone, Minnelusa Formation, 

and Minnekahta Limestone are used extensively. These 

aquifers are collectively confined by the underlying 

Precambrian rocks and the overlying Spearfish Formation. Individually, these aquifers are separated by minor 

confining layers or by low-permeability layers within 

the individual units. In general, ground-water flow in 

these aquifers is radially outward from the central core 

of the Black Hills. Although the lateral component of 

flow generally predominates, the vertical component of 

flow, and thus leakage between these aquifers, can be 

extremely variable (Peter, 1985; Greene, 1993).

Although the Precambrian basement rocks 

generally have low permeability and form the lower 

confining unit for the series of sedimentary aquifers 

(fig. 16), localized aquifers occur in many locations in 

the crystalline core of the Black Hills, where enhanced 

secondary permeability has resulted from weathering 

and fracturing. Where the Precambrian rocks are saturated, unconfined (water-table) conditions generally 

occur and topography can strongly control groundwater flow directions.

The Deadwood Formation contains the Deadwood aquifer, which overlies the Precambrian rocks. 

The Deadwood aquifer, which is used mainly by 

domestic and municipal users near its outcrop area, 

receives recharge primarily from precipitation on the 

outcrop. There may be some hydraulic connection 

between the Deadwood aquifer and the underlying 

weathered Precambrian rocks, but regionally the 

Precambrian rocks act as a lower confining unit to the 

Deadwood aquifer. The Whitewood and Winnipeg Formations, where present, act as overlying semiconfining 

units to the Deadwood aquifer (Strobel and others, 

1999). The Whitewood and Winnipeg Formations 

locally may transmit water and exchange water with 

the Deadwood aquifer, but regionally are not considered aquifers. Where the Whitewood and Winnipeg 

Formations are absent, the Deadwood aquifer is in contact with the overlying Englewood Formation, which 

was included as part of the Madison aquifer for this 

study.

The Madison aquifer generally occurs within the 

karstic upper part of the Madison Limestone, where 

numerous fractures and solution openings have created 

extensive secondary porosity and permeability. Strobel 

and others (1999) included the entire Madison Limestone and the Englewood Formation in their delineation 

of the Madison aquifer. Thus, in this report, outcrops of 

the Madison Limestone and Englewood Formation 

(fig. 14) are referred to as the outcrop of the Madison 

Limestone for simplicity. The Madison aquifer receives 

significant recharge from streamflow losses and precipitation on the outcrop. Low-permeability layers in the 

lower part of the Minnelusa Formation generally act as 

an upper confining unit to the Minnelusa aquifer. However, karst features in the upper part of the Madison 

Limestone may have reduced the effectiveness of the 

overlying confining unit in some locations.

The Minnelusa aquifer occurs within layers of 

sandstone, dolomite, and anhydrite in the lower portion 

of the Minnelusa Formation and sandstone and anhydrite in the upper portion. The Minnelusa aquifer has 

primary porosity in the sandstone units and secondary 

porosity from collapse breccia associated with dissolution of interbedded evaporites and fracturing. The 

Minnelusa aquifer receives significant recharge from 

streamflow losses and precipitation on the outcrop. 

Streamflow recharge to the Minnelusa aquifer generally is less than to the Madison aquifer (Carter, 

Driscoll, and Hamade, 2001), which is preferentially 

recharged because of its upslope location. The Minnelusa aquifer is confined by the overlying Opeche 

Shale.

Both the Madison and Minnelusa aquifers are 

potential sources for numerous large artesian springs in 
24 Hydrology of the Black Hills Area, South Dakota

the Black Hills area, and hydraulic connections 

between the two aquifers are possible in other locations 

(Naus and others, 2001). Ground-water flowpaths and 

velocities in both aquifers are influenced by anisotropic 

and heterogeneous hydraulic properties caused by 

secondary porosity. 

The Minnekahta aquifer, which overlies the 

Opeche Shale, typically is very permeable, but well 

yields can be limited by the small aquifer thickness. 

The Minnekahta aquifer receives significant recharge 

from precipitation on the outcrop and some additional 

recharge from streamflow losses. The overlying 

Spearfish Formation acts as a confining unit to the 

aquifer and to other underlying Paleozoic aquifers. 

Hence, most of the artesian springs occur near the 

outcrop of the Spearfish Formation.

Within the Mesozoic rock interval, the Inyan 

Kara Group comprises an aquifer that is used extensively. Aquifers in various other units of the Mesozoic 

rock interval are used locally to lesser degrees. The 

Inyan Kara aquifer receives recharge primarily from 

precipitation on the outcrop. The Inyan Kara aquifer 

also may receive recharge from leakage from the 

underlying Paleozoic aquifers (Swenson, 1968; Gott 

and others, 1974). As much as 4,000 ft of Cretaceous 

shales act as the upper confining unit to aquifers in the 

Mesozoic rock interval.

Confined (artesian) conditions generally exist 

within the sedimentary aquifers where an upper confining layer is present. Under confined conditions, 

water in a well will rise above the top of the aquifer in 

which it is completed. Flowing wells will result when 

drilled in areas where the water level, or potentiometric 

surface, is above the land surface. Flowing wells and 

artesian springs that originate from confined aquifers 

are common around the periphery of the Black Hills.

Numerous headwater springs originating from 

the Paleozoic units at high altitudes on the western side 

of the study area provide base flow for many streams. 

These streams flow across the crystalline core of the 

Black Hills, and most streams generally lose all or part 

of their flow as they cross the outcrops of the Madison 

Limestone (Rahn and Gries, 1973; Hortness and 

Driscoll, 1998). Karst features of the Madison Limestone, including sinkholes, collapse features, solution 

cavities, and caves, are responsible for the Madison 

aquifer’s capacity to accept recharge from streamflow. 

Large streamflow losses also occur in many locations 

within the outcrop of the Minnelusa Formation 

(Hortness and Driscoll, 1998). Large artesian springs, 

originating primarily from the Madison and Minnelusa 

aquifers, occur in many locations downgradient from 

these loss zones, most commonly within or near the 

outcrop of the Spearfish Formation. These springs provide an important source of base flow in many streams 

beyond the periphery of the Black Hills (Rahn and 

Gries, 1973; Miller and Driscoll, 1998).

Characteristics and Properties of Major Aquifers

Aquifer characteristics and properties for the 

major aquifers in the study area (Deadwood, Madison, 

Minnelusa, Minnekahta, and Inyan Kara aquifers) are 

presented in this section. Aquifer characteristics, 

including areal extent, thickness, and storage volume, 

are presented in table 1. Aquifer characteristics for the 

Precambrian aquifer also are presented because 

numerous wells are completed in this aquifer in the 

crystalline core of the Black Hills. The areal extent of 

the aquifers was determined using a geographic information system (GIS) coverage by Williamson and 

others (2000) of the hydrogeologic unit map by Strobel 

and others (1999) for the study area.

Localized aquifers occur in the Precambrian 

igneous and metamorphic rocks that make up the crystalline core of the Black Hills and are referred to collectively as the Precambrian aquifer. The Precambrian 

aquifer is not continuous, and ground-water flow is 

mainly controlled by secondary permeability caused by 

fracturing and weathering. The Precambrian aquifer is 

considered to be contained in the area where the Precambrian rocks are exposed in the central core, which 

has an area of approximately 825 mi2

 in the study area. 

The thickness of the aquifer has been estimated by 

Rahn (1985) to be generally less than 500 ft, which was 

considered the average thickness (table 1). Wells in the 

Custer area have been completed at depths greater than 

1,000 ft, indicating that the Precambrian aquifer is 

thicker in some locations. The Precambrian aquifer is 

mostly unconfined, but may have locally confined conditions. The area of the sedimentary aquifers is smaller 

than the area of the Precambrian rocks because erosion 

has removed the sedimentary rocks in the central core 

of the Black Hills.
Ground-Water Framework 25

Table 1. Summary of the characteristics of major and Precambrian aquifers in the study area

[mi2, square miles; ft, feet; acre-ft, acre-feet]

Aquifer

Area

extent

(mi2)

Maximum

formation

thickness

(ft)

Average

saturated

thickness

(ft)

Effective

porosity1

Estimated

amount of

recoverable

water in storage2

(million acre-ft)

Precambrian 35,041 -- 1500 0.01 2.6

Deadwood 4,216 500 226 .05 30.5

Madison 4,113 1,000 4

521 .05 562.7

Minnelusa 3,623 1,175 6736 .05 570.9

Minnekahta 3,082 65 50 .05 4.9

Inyan Kara 2,512 900 310 .17 84.7

Combined storage for major and Precambrian aquifers 256.3

1From Rahn (1985).

2Storage estimated by multiplying area times average thicknesses times effective porosity. 3The area used in storage calculation was the area of the exposed Precambrian rocks, which is 825 mi2

. 4Average saturated thickness of the confined area of the Madison aquifer. The unconfined area had an average saturated 

thickness of 300 ft. 5Storage values are the summation of storage in the confined and unconfined areas. 6Average saturated thickness of the confined area of the Minnelusa aquifer. The unconfined area had an average saturated 

thickness of 142 ft.

Large amounts of water are stored within the 

major aquifers, but not all of it is recoverable because 

some of the water is contained in unconnected pore 

spaces. Thus, effective porosity, which is the porosity 

of a rock that consists of interconnected voids, was 

used in estimating the amount of recoverable water in 

storage (table 1). Where aquifer units are not fully 

saturated (generally in and near outcrop areas), the 

saturated thickness is less than the formation thickness 

and the aquifer is unconfined. For the Madison and 

Minnelusa aquifers, it was possible to delineate the 

saturated thickness of the unconfined portions of these 

aquifers, as discussed later in this section. Average 

saturated thicknesses of the unconfined and confined 

portions of the Madison and Minnelusa aquifers were 

used in storage estimates for these aquifers. For the 

other major aquifers, full saturation was assumed 

because more detailed information was not available. 

The total volume of recoverable water stored in 

the major aquifers (including the Precambrian aquifer) 

within the study area is estimated as 256 million 

acre-ft. The largest storage volume is for the Inyan 

Kara aquifer because of the large effective porosity 

(0.17). Storage in the Minnelusa aquifer is larger than 

in the Madison aquifer, primarily because of larger 

average saturated thickness.

Well yields (fig. 18) for the major aquifers were 

obtained from the USGS Ground Water Site Inventory 

(GWSI) database. The mean well yields for the aquifers generally are much higher than the median well 

yields because some well yields are very high. Well 

yields generally are lower for wells completed in the 

Precambrian rocks than the major aquifers because the 

Precambrian aquifer is not continuous and most of the 

available water is stored in fractures. The Madison 

aquifer has the potential for high well yields, and the 

mean and median well yields are higher in the Madison 

aquifer than the other major aquifers. The Minnelusa 

aquifer also has the potential for high well yields. Low 

well yields are possible in some locations for all the 

major aquifers.
26 Hydrology of the Black Hills Area, South Dakota

Aquifer properties, including hydraulic conductivity, transmissivity, storage coefficient, and porosity, 

are presented in table 2 for the major aquifers and the 

Precambrian aquifer. The estimates presented for the 

various aquifer properties are based on previous 

studies. In general, the Madison aquifer has the highest 

hydraulic conductivity and transmissivity estimates of 

the major aquifers. Transmissivity and hydraulic conductivity also may be high in the Minnelusa aquifer. 

The Inyan Kara aquifer generally has the highest effective porosity of the major aquifers.

The potentiometric surfaces of the Madison and 

Minnelusa aquifers are shown in figures 19 and 20, 

respectively. In many locations, ground-water flow in 

these aquifers follows the bedding dip, which generally 

is radially away from the central part of the uplift. 

Structural features, such as folds and faults, may have 

local influence on ground-water flowpaths. Groundwater flowpaths and velocities also are heavily influenced by anisotropic and heterogeneous hydraulic 

properties of the Madison aquifer. Flowpaths are not 

necessarily orthogonal to equipotential lines because of 

highly variable directional transmissivities and may be 

further influenced by vertical flow components 

between the Madison and Minnelusa aquifers. Long 

(2000) described anisotropy in the Madison aquifer in 

the Rapid City area that causes ground-water flow to be 

nearly parallel to mapped equipotential lines in some 

cases. Regional ground-water flow from the west may 

influence the potentiometric surface in both aquifers in 

the northern and southwestern parts of the study area. 

Locations of artesian springs that probably originate 

from ground-water discharge from the Madison or 

Minnelusa aquifers and have potential to influence 

potentiometric surfaces also are shown in figures 19 

and 20.

Figure 18. Boxplots showing distribution of well yields from selected aquifers (data obtained from U.S. 

Geological Survey Ground Water Site Inventory database).

561 137 166 433 64 246

Precambrian Deadwood Madison Minnelusa Minnekahta Inyan

Kara

AQUIFER

0.01

10,000

0.02

0.05

0.1

0.2

0.5

1

2

5

10

20

50

100

200

500

1,000

2,000

5,000

WELL YIELD, IN GALLONS PER MINUTE

EXPLANATION

10th percentile

25th percentile

Median

75th percentile

90th percentile

561 Number of wells

 with yield data

Minimum

Maximum

Mean *

*

* *

*

*

*
Ground-Water Framework 27

Table 2. Estimates of hydraulic conductivity, transmissivity, storage coefficient, and porosity from previous

investigations 

[ft/d, feet per day; ft2/d, feet squared per day; --, no data; <, less than]

Source

Hydraulic

conductivity

(ft/d)

Transmissivity

(ft2/d)

Storage

coefficient

Total

porosity/

effective 

porosity

Area represented

Precambrian aquifer

Rahn, 1985 -- -- -- 0.03/0.01 Western South Dakota

Galloway and Strobel, 2000 450 - 1,435 0.10/-- Black Hills area

Deadwood aquifer

Downey, 1984 -- 250 - 1,000 -- -- Montana, North Dakota, South 

Dakota, Wyoming

Rahn, 1985 -- -- -- 0.10/0.05 Western South Dakota

Madison aquifer

Konikow, 1976 -- 860 - 2,200 -- -- Montana, North Dakota, South 

Dakota, Wyoming

Miller, 1976 -- 0.01 - 5,400 -- -- Southeastern Montana

Blankennagel and others, 1977 2.4x10-5 - 1.9 -- -- -- Crook County, Wyoming

Woodward-Clyde Consultants, 

1980

-- 3,000 2x10-4 - 3x10-4 -- Eastern Wyoming, western South 

Dakota

Blankennagel and others, 1981 -- 5,090 2x10-5 -- Yellowstone County, Montana

Downey, 1984 -- 250 - 3,500 -- -- Montana, North Dakota, South 

Dakota, Wyoming

Plummer and others, 1990 -- -- 1.12x10-6 - 3x10-5 -- Montana, South Dakota, Wyoming

Rahn, 1985 -- -- -- 0.10/0.05 Western South Dakota

Cooley and others, 1986 1.04 -- -- -- Montana, North Dakota, South 

Dakota, Wyoming, Nebr.

Kyllonen and Peter, 1987 -- 4.3 - 8,600 -- -- Northern Black Hills

Imam, 1991 9.0x10-6 -- -- -- Black Hills area

Greene, 1993 -- 1,300 - 56,000 0.002 0.35/-- Rapid City area

Tan, 1994 5 - 1,300 -- -- 0.05 Rapid City area

Greene and others, 1999 -- 2,900 - 41,700 3x10-4 - 1x10-3 -- Spearfish area

Carter, Driscoll, Hamade, and 

Jarrell, 2001

-- 100 - 7,400 -- -- Black Hills area

Minnelusa aquifer

Blankennagel and others, 1977 <2.4x10-5 - 1.4 -- -- -- Crook County, Wyoming

Pakkong, 1979 -- 880 -- -- Boulder Park area, South Dakota

Woodward-Clyde Consultants, 

1980

-- 30 - 300 6.6x10-5 - 2.0x10-4 -- Eastern Wyoming, western South 

Dakota
28 Hydrology of the Black Hills Area, South Dakota

Minnelusa aquifer—Continued

Rahn, 1985 -- -- -- 0.10/0.05 Western South Dakota

Kyllonen and Peter, 1987 -- 0.86 - 8,600 -- -- Northern Black Hills

Greene, 1993 -- 12,000 0.003 0.1/-- Rapid City area

Tan, 1994 32 -- -- -- Rapid City area

Greene and others, 1999 -- 267 - 9,600 5.0x10-9 - 7.4x10-5 -- Spearfish area

Carter, Driscoll, Hamade, and 

Jarrell, 2001

-- 100 - 7,400 -- -- Black Hills area

Minnekahta aquifer

Rahn, 1985 -- -- -- 0.08/0.05 Western South Dakota

Inyan Kara aquifer

Niven, 1967 0 - 100 -- -- -- Eastern Wyoming, western South 

Dakota

Miller and Rahn, 1974 0.944 178 -- -- Black Hills area

Gries and others, 1976 1.26 250 - 580 2.1x10-5 - 2.5x10-5 -- Wall area, South Dakota

Boggs and Jenkins, 1980 -- 50 - 190 1.4x10-5 - 1.0x10-4 -- Northwestern Fall River County

Bredehoeft and others, 1983 8.3 -- 1.0x10-5 -- South Dakota

Rahn, 1985 -- -- -- 0.26/0.17 Western South Dakota

Kyllonen and Peter, 1987 -- 0.86 - 6,000 -- -- Northern Black Hills 

Table 2. Estimates of hydraulic conductivity, transmissivity, storage coefficient, and porosity from previous

investigations–Continued

[ft/d, feet per day; ft2/d, feet squared per day; --, no data; <, less than]

Source

Hydraulic

conductivity

(ft/d)

Transmissivity

(ft2/d)

Storage

coefficient

Total

porosity/

effective 

porosity

Area represented
Ground-Water Framework 29

Figure 19. Potentiometric surface of the Madison aquifer and locations of major artesian springs.

N. Fork Rapid Cr

Belle Fourche

Reservoir

FOURCHE

Victoria

Spring

Rhoads Fork

Coolidge

Highland

Angostura

Reservoir

Castl e Cr

N. Fork Castle Cr

Hell

Canyon

Canyon

Red

Bear

Gulch

Creek

Crow

Sheridan

Lake

Hot Brook Canyon

Deerfield

Reservoir

Pactola

Reservoir

Indian Cr

Horse

Creek

Owl

BELLE

Creek

RIVER

REDWATER

R I VER

Creek

Cr

Little Spearfish

Spearfish

Creek

Spearfish

Whitewood

Creek

Creek

Bear

Butte

Elk

Elk

Creek

Creek

Creek

Boxelder

Rapid

Rapid

Creek

Creek

Creek

Spring

Creek

French

Creek

Creek

Creek

Grace

Creek

Creek

Creek

S. Fork

Gillette

S. Fork Rapid Cr

Battle

French

Beaver

Beaver

Creek

Creek

Creek

Creek

Creek

Fall R

Hat

Creek

Creek

Horsehead

CHEYENNE

RIVER

Cottonwood

Hay Creek

Bottom

False

Creek

Spokane

Lame

Johnny

Higgins

Beaver

Cr

Whitetail

Cr

Cr

Cr Cr

Gulch

Annie

Squaw

Deadwood

Creek

Alkali

Iron Cr

Elk

Little

Creek

Castle

Castle

Creek

Creek

Bear Gulch

Cr Strawberry

Boles

Canyon

Canyon

Redbird Canyon

Cold

Beaver

Spring

C s

reek

Creek

Whitewood

Spearfish

Saint

Onge

DEADWOOD

Lead

BELLE FOURCHE

Newell

STURGIS

Blackhawk

Piedmont

Tilford

Box Elder 

Hill City

Hermosa

CUSTER

HOT SPRINGS

Edgemont

Minnekahta

Tinton Central

City

Roubaix

Nemo

Vale

Nisland

Hayward

Keystone

Rochford

Pringle

Fairburn

Buffalo Gap

Dewey

Cascade

Springs

Igloo

Provo

Oral

Rockerville

RAPID CITY

LIMESTONE PLATEAU

 Wind Cave

National Park

Jewel Cave

National

Monument

Mt. Rushmore

National

Memorial

CUSTER

STATE

PARK

Wind

Cave

Harney

Peak

x

Ellsworth

Air Force

Base

BUTTE CO

LAWRENCE CO MEADE CO

PENNINGTON CO

CUSTER CO

FALL RIVER CO

WYOMING

SOUTH DAKOTA

3,700

3,600

5,800

4,800

4,400

6,600

3,600

6,400

3,500

3,400

3,800

4,000 4,200

4,400

5,000 5,200

4,800

3,200

5,600

5,400

4,600

6,000

6,200

4,200

6,400

4,000

4,400

6,400

3,400

3,6003,800

4,200

2,600

4,000

2,800

3,000

3,000

6,600

6,600

6,000

6,400

6,200

5,500

5,000

4,500

3,600

4,000

3,900

3,700

3,200

3,600

3,500

4,600

3,400

3,400

3,800

3,900

3,800

3,700

3,000

Cool Spring

Hot Brook Spring

Cascade

Springs

Beaver

Creek

Spring

Battle

Creek

Spring

Evans Plunge Spring

Elk Creek

Springs

Cleghorn/

Jackson

Springs

City

Springs

Higgins Gulch

Spring

Old Spearfish

Hatchery Cox

Lake

Mirror

Lake

and

McNenny

Rearing

Pond

Grace

Coolidge

Creek

Spring

0 10 20

0 10 20 MILES

KILOMETERS

EXPLANATION

OUTCROP OF MADISON LIME-

 STONE (from Strobel and

 others, 1999)

MADISON LIMESTONE ABSENT

 (from Carter and Redden, 1999d)

POTENTIOMETRIC CONTOUR--

 Shows altitude at which water

 would have stood in tightly cased,

 nonpumping wells (modified from

 Strobel and others, 2000a).

 Contour interval 100, 200, or

 500 feet, where appropriate.

 Dashed where inferred. Datum

 is sea level

MADISON LIMESTONE PRESENT,

 BUT OVERLAIN BY SURFICIAL

 DEPOSITS (from Carter and

 Redden, 1999d)

FAULT--Dashed where approxi-

 mated. Bar and ball on down-

 thrown side

ANTICLINE--Showing trace of axial

 plane and direction of plunge.

 Dashed where approximated

SYNCLINE--Showing trace of axial

 plane and direction of plunge.

 Dashed where approximated

MONOCLINE--Showing trace of

 axial plane. Dashed where

 approximated

DOME--Symbol size approximately

 proportional to size of dome.

 Dome asymmetry indicated by

 arrow length

ARTESIAN SPRING

104o 45' 103o

30'

15' 103o

30'

44o

45'

15'

44o

45'

30'

43o

15'

Base modified from U.S. Geological Survey digital data,

1:100,000, 1977, 1979, 1981, 1983, 1985

Rapid City, Office of City Engineer map, 1:18,000, 1996

Universal Transverse Mercator projection, zone 13
30 Hydrology of the Black Hills Area, South Dakota

Figure 20. Potentiometric surface of the Minnelusa aquifer and locations of major artesian springs.

N. Fork Rapid Cr

Belle Fourche

Reservoir

FOURCHE

Victoria

Spring

Rhoads Fork

Coolidge

Highland

Angostura

Reservoir

Castl e Cr

N. Fork Castle Cr

Hell

Canyon

Canyon

Red

Bear

Gulch

Creek

Crow

Sheridan

Lake

Hot Brook Canyon

Deerfield

Reservoir

Pactola

Reservoir

Indian Cr

Horse

Creek

Owl

BELLE

Creek

RIVER

REDWATER

R I VER

Creek

Cr

Little Spearfish

Spearfish

Whitewood

Creek

Creek

Bear

Butte

Elk

Elk

Creek

Creek

Creek

Boxelder

Rapid

Rapid

Creek

Creek

Creek

Spring

Creek

Creek

Creek

Grace

Creek

Creek

Creek

S. Fork

Gillette

S. Fork Rapid Cr

Battle

French

Beaver

Beaver

Creek

Creek

Creek

Creek

Creek

Fall R

Hat

Creek

Creek

Horsehead

CHEYENNE

RIVER

Cottonwood

Hay Creek

Bottom

False

Creek

Spokane

Lame

Johnny

Higgins

Beaver

Cr

Whitetail

Cr

Cr

Cr Cr

Gulch

Annie

Squaw

Deadwood

Creek

Alkali

Iron Cr

Elk

Little

Creek

Castle

Castle

Creek

Creek

Bear Gulch

Cold B roo k

Cr Strawberry

Boles

Canyon

Canyon

Redbird Canyon

Cold

Beaver

Spring

C s

reek

Creek

Whitewood

Spearfish

Saint

Onge

DEADWOOD

Lead

BELLE FOURCHE

Newell

STURGIS

Blackhawk

Piedmont

Tilford

Box Elder 

Hill City

Hermosa

CUSTER

HOT SPRINGS

Edgemont

Minnekahta

Tinton Central

City

Roubaix

Nemo

Vale

Nisland

Hayward

Keystone

Rochford

Pringle

Fairburn

Buffalo Gap

Dewey

Cascade

Springs

Igloo

Provo

Oral

Rockerville

RAPID CITY

LIMESTONE PLATEAU

 Wind Cave

National Park

Jewel Cave

National

Monument

Mt. Rushmore

National

Memorial

CUSTER

STATE

PARK

Wind

Cave

Harney

Peak

x

Ellsworth

Air Force

Base

BUTTE CO

LAWRENCE CO MEADE CO

PENNINGTON CO

CUSTER CO

FALL RIVER CO

WYOMING

SOUTH DAKOTA

3,000

4,000

4,200

6,600

6,200

3,400

6,000

5,400

5,800

5,000

5,200

4,400

4,200

2,800

3,600

3,600

3,400

4,000

3,200

3,000

4,400

4,600

3,800

4,800

4,200

5,000

4,0003,800

3,600

6,000

6,200

6,400

6,400

3,800

6,800

6,600

3,800

6,000

6,400

6,200 6,200

5,600

5,800

6,000

2,800

3,000

3,200

5,400

3,800

3,800

4,8004,600

4,800

3,600

4,600

3,400

4,200

4,400

4,000

3,600

2,600

2,800

3,000

3,200

3,400

Cool Spring

Hot Brook Spring

Cascade

Springs

Beaver

Creek

Spring

Battle

Creek

Spring Grace

Coolidge

Creek

Spring

Evans Plunge Spring

Higgins Gulch

Spring

Old Spearfish

Hatchery

Mirror

Lake

and

McNenny

Rearing

Pond

Elk Creek

Springs

City

Springs

Cox

Lake

Cleghorn/

Jackson

Springs

0 10 20

0 10 20 MILES

KILOMETERS

EXPLANATION

OUTCROP OF MINNELUSA

 FORMATION (modified from

 Strobel and others, 1999)

MINNELUSA FORMATION

 ABSENT (from Carter and

 Redden, 1999c)

MINNELUSA FORMATION

 PRESENT, BUT OVERLAIN BY

 SURFICIAL DEPOSITS (from

 Carter and Redden, 1999c)

POTENTIOMETRIC CONTOUR--

 Shows altitude at which water

 would have stood in tightly

 cased, nonpumping wells

 (modified from Strobel and

 others, 2000b). Contour

 interval 200 feet. Dashed where

 inferred. Datum is sea level 

FAULT--Dashed where approxi-

 mated. Bar and ball on down-

 thrown side

ANTICLINE--Showing trace of axial

 plane and direction of plunge.

 Dashed where approximated

SYNCLINE--Showing trace of axial

 plane and direction of plunge.

 Dashed where approximated

MONOCLINE--Showing trace of

 axial plane. Dashed where

 approximated

DOME--Symbol size approximately

 proportional to size of dome.

 Dome asymmetry indicated by

 arrow length

ARTESIAN SPRING

104o 45' 103o

30'

15' 103o

30'

44o

45'

15'

44o

45'

30'

43o

15'

Base modified from U.S. Geological Survey digital data,

1:100,000, 1977, 1979, 1981, 1983, 1985

Rapid City, Office of City Engineer map, 1:18,000, 1996

Universal Transverse Mercator projection, zone 13
Surface-Water Framework 31

Maps showing the saturated thickness of the 

unconfined areas of the Madison and Minnelusa aquifers are shown in figures 21 and 22, respectively. Both 

the Madison and Minnelusa aquifers are unconfined 

near their outcrops and confined (fully saturated) at 

some distance downdip from their outcrops. In general, 

the saturated thickness is less than 200 ft for most of the 

outcrop areas. These areas are especially susceptible to 

drought conditions, and the formations may even be 

dry in these areas regardless of precipitation conditions. In most areas, the aquifers are fully saturated 

within a short distance downdip of the outcrops. However, in the southwest part of the study area, neither 

aquifer is fully saturated for a distance of about 6 mi 

downdip of the respective outcrops.

Although the Limestone Plateau area is a large 

recharge area for the Madison and Minnelusa aquifers, 

saturated thicknesses generally are small within these 

aquifers in this area. Very few wells have been successfully completed in this area, especially within the 

Madison Limestone, where saturated conditions generally occur only near the bottom of the formation. Saturated thicknesses are limited by the discharge of 

springs along the eastern edge of the Plateau and by 

ground-water flow to the west. Fluctuations in groundwater levels in this area generally are smaller than other 

areas.

Overview of Other Aquifers

In addition to the major aquifers, many other 

aquifers are used throughout the study area. The Newcastle Sandstone, White River Group, and the unconsolidated units are considered aquifers where saturated 

(Strobel and others, 1999). In addition, many of the 

semiconfining and confining units shown in figure 14 

may contain local aquifers. This section provides a 

brief overview from Strobel and others (1999) of other 

aquifers in the study area that are contained in various 

units from oldest to youngest.

The Whitewood Formation, where present, may 

contain a local aquifer, but seldom is used because of 

more reliable sources in the adjacent Madison or 

Deadwood aquifers. Local aquifers may exist in the 

Spearfish confining unit where gypsum and anhydrite 

have been dissolved, increasing porosity and permeability; these aquifers are referred to as the Spearfish 

aquifer in this report. The Jurassic-sequence semiconfining unit consists of shales and sandstones. Overall, 

this unit is semiconfining because of the low permeability of the interbedded shales; however, local 

aquifers exist in some formations such as the Sundance 

and Morrison Formations. These aquifers are referred 

to as the Sundance and Morrison aquifers in this report.

The Cretaceous-sequence confining unit mainly 

includes shales of low permeability, such as the Pierre 

Shale; local aquifers in the Pierre Shale are referred to 

as the Pierre aquifer in this report. Within the Graneros 

Group, the Newcastle Sandstone contains an important 

minor aquifer referred to as the Newcastle aquifer. 

Because water-quality characteristics (discussed in a 

subsequent section of this report) are very different 

between the Newcastle aquifer and the other units in 

the Graneros Group, data are presented for the Newcastle aquifer separately from the other units in the 

Graneros Group, known as the Graneros aquifer in this 

report.

Tertiary intrusive units are present only in the 

northern Black Hills, and generally are relatively 

impermeable, although “perched” ground water often 

is associated with intrusive sills. The White River 

aquifer consists of various discontinuous units of sandstone and channel sands along the eastern flank of the 

Black Hills and is considered a minor aquifer where 

saturated. Unconsolidated deposits of Tertiary or 

Quaternary age, including alluvium, colluvium, and 

wind-blown deposits, all have the potential to be local 

aquifers where they are saturated.

Surface-Water Framework

Streamflow within the study area is highly influenced by climatic and geologic conditions. The base 

flow of most streams in the Black Hills originates in the 

higher altitudes, where relatively large precipitation 

and small evapotranspiration result in more water being 

available for springflow and streamflow. Many streams 

have headwater springs originating from the Paleozoic 

carbonate rocks on the western side of the study area. 

Most of these streams flow in a generally eastward 

direction across the Precambrian rocks of the crystalline core and subsequently lose all or part of their flow 

where Paleozoic outcrops are crossed farther downstream (Rahn and Gries, 1973). Large artesian springs 

occur in many locations downgradient from loss zones, 

most commonly within or near the outcrop of the 

Spearfish Formation. These springs provide an important source of base flow in many streams beyond the 

periphery of the Black Hills (Rahn and Gries, 1973; 

Miller and Driscoll, 1998).
32 Hydrology of the Black Hills Area, South Dakota

Figure 21. Saturated thickness of the Madison aquifer.

N. Fork Rapid Cr

Belle Fourche

Reservoir

FOURCHE

Victoria

Spring

Rhoads Fork

Coolidge

Highland

Angostura

Reservoir

Castl e Cr

N. Fork Castle Cr

Hell

Canyon

Canyon

Red

Bear

Gulch

Creek

Crow

Sheridan

Lake

Hot Brook Canyon

Cox

Lake

Deerfield

Reservoir

Pactola

Reservoir

Indian Cr

Horse

Creek

Owl

BELLE

Creek

RIVER

REDWATER

R I VER

Creek

Cr

Little Spearfish

Spearfish

Creek

Spearfish

Whitewood

Creek

Creek

Bear

Butte

Elk

Elk

Creek

Creek

Creek

Boxelder

Rapid

Rapid

Creek

Creek

Creek

Spring

Creek

French

Creek

Creek

Creek

Grace

Creek

Creek

Creek

S. Fork

Gillette

S. Fork Rapid Cr

Battle

French

Beaver

Beaver

Creek

Creek

Creek

Creek

Creek

Fall R

Hat

Creek

Creek

Horsehead

CHEYENNE

RIVER

Cottonwood

Hay Creek

Bottom

False

Creek

Spokane

Lame

Johnny

Higgins

Beaver

Cr

Whitetail

Cr

Cr

Cr Cr

Gulch

Annie

Squaw

Deadwood

Creek

Alkali

Iron Cr

Elk

Little

Creek

Castle

Castle

Creek

Creek

Bear Gulch

Cr Strawberry

Boles

Canyon

Canyon

Redbird Canyon

Cold

Beaver

Spring

C s

reek

Creek

Whitewood

Spearfish

Saint

Onge

DEADWOOD

Lead

BELLE FOURCHE

Newell

STURGIS

Blackhawk

Piedmont

Tilford

Box Elder 

Hill City

Hermosa

CUSTER

HOT SPRINGS

Edgemont

Minnekahta

Tinton Central

City

Roubaix

Nemo

Vale

Nisland

Hayward

Keystone

Rochford

Pringle

Fairburn

Buffalo Gap

Dewey

Cascade

Springs

Igloo

Provo

Oral

Rockerville

RAPID CITY

LIMESTONE PLATEAU

 Wind Cave

National Park

Jewel Cave

National

Monument

Mt. Rushmore

National

Memorial

CUSTER

STATE

PARK

Wind

Cave

Harney

Peak

x

Ellsworth

Air Force

Base

BUTTE CO

LAWRENCE CO MEADE CO

PENNINGTON CO

CUSTER CO

FALL RIVER CO

WYOMING

SOUTH DAKOTA

0 10 20

0 10 20 MILES

KILOMETERS

EXPLANATION

Less than 200

SATURATED THICKNESS OF

 MADISON LIMESTONE, IN

 FEET (from Clawges, 2000a)

MADISON LIMESTONE ABSENT

 (from Carter and Redden, 1999d)

OUTCROP OF MADISON LIME-

 STONE (from Strobel and others,

 1999)

200 to 400

400 to 600

600 to 800

Fully saturated

104o 45' 103o

30'

15' 103o

30'

44o

45'

15'

44o

45'

30'

43o

15'

Base modified from U.S. Geological Survey digital data,

1:100,000, 1977, 1979, 1981, 1983, 1985

Rapid City, Office of City Engineer map, 1:18,000, 1996

Universal Transverse Mercator projection, zone 13
Surface-Water Framework 33

Figure 22. Saturated thickness of the Minnelusa aquifer.

N. Fork Rapid Cr

Belle Fourche

Reservoir

FOURCHE

Victoria

Spring

Rhoads Fork

Coolidge

Highland

Angostura

Reservoir

Castl e Cr

N. Fork Castle Cr

Hell

Canyon

Canyon

Red

Bear

Gulch

Creek

Crow

Sheridan

Lake

Hot Brook Canyon

Cox

Lake

Deerfield

Reservoir

Pactola

Reservoir

Indian Cr

Horse

Creek

Owl

BELLE

Creek

RIVER

REDWATER

R I VER

Creek

Cr

Little Spearfish

Spearfish

Creek

Spearfish

Whitewood

Creek

Creek

Bear

Butte

Elk

Elk

Creek

Creek

Creek

Boxelder

Rapid

Rapid

Creek

Creek

Creek

Spring

Creek

French

Creek

Creek

Creek

Grace

Creek

Creek

Creek

S. Fork

Gillette

S. Fork Rapid Cr

Battle

French

Beaver

Beaver

Creek

Creek

Creek

Creek

Creek

Fall R

Hat

Creek

Creek

Horsehead

CHEYENNE

RIVER

Cottonwood

Hay Creek

Bottom

False

Creek

Spokane

Lame

Johnny

Higgins

Beaver

Cr

Whitetail

Cr

Cr

Cr Cr

Gulch

Annie

Squaw

Deadwood

Creek

Alkali

Iron Cr

Elk

Little

Creek

Castle

Castle

Creek

Creek

Bear Gulch

Cold B roo k

Cr Strawberry

Boles

Canyon

Canyon

Redbird Canyon

Cold

Beaver

Spring

C s

reek

Creek

Whitewood

Spearfish

Saint

Onge

DEADWOOD

Lead

BELLE FOURCHE

Newell

STURGIS

Blackhawk

Piedmont

Tilford

Box Elder 

Hill City

Hermosa

CUSTER

HOT SPRINGS

Edgemont

Minnekahta

Tinton Central

City

Roubaix

Nemo

Vale

Nisland

Hayward

Keystone

Rochford

Pringle

Fairburn

Buffalo Gap

Dewey

Cascade

Springs

Igloo

Provo

Oral

Rockerville

RAPID CITY

LIMESTONE PLATEAU

 Wind Cave

National Park

Jewel Cave

National

Monument

Mt. Rushmore

National

Memorial

CUSTER

STATE

PARK

Wind

Cave

Harney

Peak

x

Ellsworth

Air Force

Base

BUTTE CO

LAWRENCE CO MEADE CO

PENNINGTON CO

CUSTER CO

FALL RIVER CO

WYOMING

SOUTH DAKOTA

0 10 20

0 10 20 MILES

KILOMETERS

EXPLANATION

Less than 200

SATURATED THICKNESS OF

 MINNELUSA FORMATION, IN FEET

 (from Clawges, 2000b)

MINNELUSA FORMATION ABSENT

 (from Carter and Redden, 1999c)

OUTCROP OF MINNELUSA FORMATION

 (from Strobel and others, 1999)

200 to 400

400 to 600

600 to 800

800 to 1,000

1,000 to 1,200

Fully saturated

No data

104o 45' 103o

30'

15' 103o

30'

44o45'

15'

44o

45'

30'

43o

15'

Base modified from U.S. Geological Survey digital data,

1:100,000, 1977, 1979, 1981, 1983, 1985

Rapid City, Office of City Engineer map, 1:18,000, 1996

Universal Transverse Mercator projection, zone 13
34 Hydrology of the Black Hills Area, South Dakota

Five hydrogeologic settings have been identified 

for the Black Hills area that influence both streamflow (Driscoll and Carter, 2001) and water-quality 

(Williamson and Carter, 2001) characteristics. These 

settings are described in the following section, which is 

followed by sections describing streamflow losses and 

streamflow regulation, both of which have large influence on many area streams.

Hydrogeologic Settings

The five hydrogeologic settings identified for the 

Black Hills area include the limestone headwater, crystalline core, loss zone, artesian spring, and exterior settings, which are represented by four areas (fig. 23). The 

loss zone and artesian spring settings have distinctly 

different streamflow characteristics but share a 

common area because many artesian springs are 

located along stream channels that also are influenced 

by streamflow losses. Locations of representative 

streamflow-gaging stations for the five hydrogeologic 

settings, which are used in subsequent descriptions of 

streamflow and water-quality characteristics, also are 

shown in figure 23.

The limestone headwater setting is considered to 

be within or near the Limestone Plateau area (fig. 23), 

where large outcrops of the Madison Limestone and 

Minnelusa Formation occur in a high-altitude area of 

generally low relief, along the South Dakota-Wyoming 

border. Most of the limestone headwater springs occur 

near the eastern edge of the Limestone Plateau in areas 

where the contact between the Madison Limestone and 

underlying geologic units (fig. 9) is exposed (fig. 14). 

Various low-permeability layers in the underlying units 

can act as confining layers, which result in lateral 

movement of ground water prior to discharge as springflow. Most recharge for these headwater springs is from 

infiltration of precipitation on outcrops of the Madison 

Limestone and Minnelusa Formation. Ground-water 

discharge from the Deadwood aquifer also can contribute to springflow. Sustained streamflow within the 

Madison and Minnelusa outcrops is very uncommon 

(Driscoll and Carter, 2001) and generally occurs only 

in limited areas where low permeability “perching” 

layers occur. Small perched springs are common especially within outcrops of the Minnelusa Formation 

along the Limestone Plateau.

The crystalline core setting consists primarily of 

igneous and metamorphic Precambrian rocks within 

the central part of the Black Hills, but also includes 

numerous Tertiary intrusives in the northern Black 

Hills (fig. 14). Unconsolidated Quaternary and Tertiary 

deposits also occur in various locations. Within this setting, ground-water discharge contributes to base flow 

of many streams; however, base flow can diminish 

rather quickly during periods of minimal precipitation.

The loss-zone setting consists of areas that are 

heavily influenced by streamflow losses that occur as 

streams cross outcrops of the Madison Limestone and 

Minnelusa Formation. The outer extent of this area is 

represented by the outer extent of the outcrop of the 

Inyan Kara Group (fig. 23). This same area is used to 

represent the artesian spring setting because many artesian springs are located along stream channels that also 

are influenced by streamflow losses. Most artesian 

springs are located downgradient from the outcrop of 

the Minnelusa Formation (fig. 23). Complex interactions between bedrock aquifers, alluvial aquifers, and 

surface water can occur within this setting.

No artesian springs are known to be located 

beyond the outcrop of the Inyan Kara Group; the area 

beyond this outcrop is referred to as the exterior setting. 

Within this setting, the influence of ground water on 

streamflow generally is relatively minor or negligible, 

with the exception of upstream influences from streamflow losses or artesian springs. Many streams also are 

influenced by irrigation withdrawals or other forms of 

regulation, as described in a subsequent section.

Streamflow Losses

Streamflow losses influence the flow of most 

streams that cross Paleozoic outcrops, especially the 

Madison Limestone and Minnelusa Formation. Most 

streams lose all of their flow up to some loss threshold. 

When streamflow exceeds this threshold, flow is maintained through the loss zones. Loss thresholds for most 

large streams were quantified by Hortness and Driscoll 

(1998) and are summarized in table 3. Individual loss 

thresholds range from negligible (no loss) to as much as 

50 ft3

/s. Streamflow losses can occur along Iron Creek 

and Higgins Gulch; however, loss thresholds are noted 

as zero because these streams receive net ground-water 

discharge from the Madison and Minnelusa aquifers. 

Newton and Jenny (1880) observed losses in Whitewood Creek; however, loss zones apparently were 

sealed by fine-grained mine tailings that have been discharged to the stream (Hortness and Driscoll, 1998).
Surface-Water Framework 35

Figure 23. Hydrogeologic settings for the Black Hills area. Locations of streamflow-gaging stations representative of the 

settings also are shown (from Driscoll and Carter, 2001).

N. Fork Rapid Cr

Belle Fourche

Reservoir

FOURCHE

Victoria

Spring

Rhoads Fork

Coolidge

Highland

Angostura

Reservoir

Castl e Cr

N. Fork Castle Cr

Hell

Canyon

Canyon

Red

Bear

Gulch

Creek

Crow

Sheridan

Lake

Hot Brook Canyon

Deerfield

Reservoir

Pactola

Reservoir

Indian Cr

Horse

Creek

Owl

BELLE

Creek

RIVER

REDWATER

R I VER

Creek

Cr

Little Spearfish

Spearfish

Creek

Spearfish

Whitewood

Creek

Creek

Bear

Butte

Elk

Elk

Creek

Creek

Creek

Boxelder

Rapid

Rapid

Creek

Creek

Creek

Spring

Creek

French

Creek

Creek

Creek

Grace

Creek

Creek

Creek

S. Fork

Redbird

Gillette

S. Fork Rapid Cr

Battle

French

Beaver

Creek

Creek

Creek

Creek

Fall R

Hat

Creek

Creek

Horsehead

CHEYENNE

RIVER

Cottonwood

Hay Creek

Bottom

False

Creek

Spokane

Lame

Johnny

Higgins

Beaver

Cr

Whitetail

Cr

Cr

Cr Cr

Gulch

Annie

Squaw

Deadwood

Creek

Alkali

Iron Cr

Elk

Little

Creek

Castle

Castle

Creek

Creek

Bear Gulch

Cr Strawberry

Boles

Canyon

Canyon

Canyon

Creek

Creek

Cr

Beaver

Creek

Creek

Cold

Springs

Sand

Beaver Stockade

Whoopup

Whitewood

Spearfish

Saint

Onge

DEADWOOD

Lead

BELLE FOURCHE

Newell

STURGIS

Blackhawk

Piedmont

Tilford

Box Elder 

Hill City

Hermosa

CUSTER

HOT SPRINGS

Edgemont

Minnekahta

Tinton Central

City

Roubaix

Nemo

Vale

Nisland

Hayward

Keystone

Rochford

Pringle

Fairburn

Buffalo

Gap

Dewey

Cascade

Springs

Igloo

Provo

Oral

Rockerville

RAPID CITY

 Wind Cave

National Park

Jewel Cave

National

Monument

Mt. Rushmore

National

Memorial

CUSTER

STATE

PARK

Wind

Cave

Harney

Peak

x

Ellsworth

Air Force

Base

BUTTE CO

LAWRENCE CO MEADE CO

PENNINGTON CO

CUSTER CO

FALL RIVER CO

WYOMING

SOUTH DAKOTA

LIMESTONE PLATEAU

Cool Spring

Hot Brook Spring

Cascade Springs

Beaver

Creek

Spring

Battle

Creek

Spring

Evans Plunge Spring

Elk Creek

Springs

Cleghorn/

Jackson

Springs

City Springs

Higgins Gulch

Spring

Old Spearfish

Hatchery Cox

Lake

Mirror

Lake

and

McNenny

Rearing

Pond

Grace

Coolidge

Creek

Spring

06402995

06404800

06406920

06395000

06402995

06412810

06412810

06395000

06395000

06436760

06436700

06437500

06400875

06400875

06429905

06392950

06402470

06423010

06408500

06408500

06437020

06403300

06429500

06392900

06408700

06408700

06430800

06430898

06436156

06430770

06430850

06424000

06430532 06430540

06433500

06422500

06407500

06404000

06404998

06405800

06403300

06402430

06402470

06402000

06400497

06400000

06409000

06408700

104o 45' 103o

30'

15' 103o

30'

44o

45'

15'

44o

45'

30'

43o

15'

0 10 20

0 10 20 MILES

KILOMETERS

STREAMFLOW-GAGING

 STATION USED FOR

 ANALYSIS OF STREAM-

 FLOW CHARACTERISTICS--

 Number is station

 identification number

Limestone headwater

Crystalline core

Loss zones

Artesian spring

Exterior

STREAMFLOW-GAGING

 STATION USED FOR

 ANALYSIS OF WATER-

 QUALITY CHARACTER-

 ISTICS--Number is station

 identification number

Limestone headwater

Crystalline core

Artesian spring

Exterior

CONNECTED OUTCROP OF

 MADISON LIMESTONE--

 Excludes erosional remnants

 (modified from Strobel and

 others, 1999)

HYDROGEOLOGIC SETTINGS

Limestone headwater

CONNECTED OUTCROP OF

 MINNELUSA FORMATION--

 Excludes erosional remnants

 (modified from Strobel and

 others, 1999)

Crystalline core

Loss zone and artesian

 spring--Bounded by outer

 extent of Inyan Kara Group,

 which approximates outer

 extent of the Black Hills area

Exterior

EXPLANATION

Base modified from U.S. Geological Survey digital data,

1:100,000, 1977, 1979, 1981, 1983, 1985

Rapid City, Office of City Engineer map, 1:18,000, 1996

Universal Transverse Mercator projection, zone 13

ARTESIAN SPRING
36 Hydrology of the Black Hills Area, South Dakota

Although most losses occur within outcrops of 

the Madison Limestone and Minnelusa Formation, 

small losses may occur to other bedrock units. Losses 

to the Deadwood Formation are minimal. Losses to the 

Minnekahta Limestone generally are small, relative to 

losses to the Madison and Minnelusa Formations; however, they are difficult to quantify because of potential 

losses to extensive alluvial deposits that commonly are 

located near Minnekahta Limestone outcrops.

Loss thresholds generally are relatively constant, 

without measurable effects from flow rate or duration 

of flow through loss zones. Changes in loss thresholds 

resulting from changes in channel conditions have been 

documented for Whitewood Creek (previously discussed), Grace Coolidge Creek, and Spring Creek 

(Hortness and Driscoll, 1998). The loss threshold for 

Grace Coolidge Creek probably was reduced by 

deposition of large quantities of fine-grained sediment 

mobilized after the Galena Fire, which occurred during 

July 1988. Streamflow losses along Spring Creek 

apparently were temporarily reduced as a result of 

efforts to seal the channel with bentonite and rocks 

during 1937-40 (Brown, 1944).

Streamflow Regulation

Many streams in the study area are affected by 

withdrawals, diversions, or reservoir regulation. The 

largest consumptive use of surface water within the 

study area is withdrawals for irrigation supplies 

(Amundson, 1998). The largest withdrawals are associated with irrigation projects along Rapid Creek and the 

Cheyenne and Belle Fourche Rivers, where Bureau of 

Reclamation storage reservoirs provide reliable water 

supplies. Angostura Reservoir (fig. 1) supplies the 

Angostura Unit; Deerfield and Pactola Reservoirs 

supply the Rapid Valley Project; and Keyhole (located 

in northeastern Wyoming) and Belle Fourche Reservoirs supply the Belle Fourche Project (Bureau of 

Reclamation, 1999). Details about these reservoirs, 

along with storage records through 1993, were reported 

by Miller and Driscoll (1998).

Large irrigation withdrawals also are made from 

Beaver Creek near Buffalo Gap and from Spearfish 

Creek and the Redwater River in the northern Black 

Hills, where streamflow is sufficiently reliable to provide consistent supplies. Smaller irrigation withdrawals are made from many other area streams. 

Table 3. Summary of loss thresholds from Black Hills 

streams to bedrock aquifers

[From Hortness and Driscoll (1998). ft3/s, cubic feet per second]

Stream name

Approximate loss 

threshold

(ft3/s)

Beaver Creek1 5

Highland Creek 10

South Fork Lame Johnny Creek 1.4

North Fork Lame Johnny Creek 2.3

French Creek 15

Battle Creek 12

Grace Coolidge Creek 21

Bear Gulch1 .4

Spokane Creek 2.2

Spring Creek 28

Rapid Creek 10

Victoria Creek 1.0

Boxelder Creek 50

Elk Creek 19

Little Elk Creek 3.3

Bear Gulch2 4

Beaver Creek2 9

Iron Creek 0

Spearfish Creek 23

Higgins Gulch 0

False Bottom Creek 15

Whitewood Creek 0

Bear Butte Creek 12

1Located in southern Black Hills.

2Located in northern Black Hills.
Hydrologic Processes 37

Streamflow in many area streams is influenced 

by a variety of other generally non-consumptive diversions and regulation mechanisms (such as smaller reservoirs). Diversions from Rapid, Elk, and Spearfish 

Creeks have historically provided water for mining 

operations (Homestake Mining Company) and municipal supplies (Central City, Deadwood, and Lead) in the 

Whitewood Creek Basin (Miller and Driscoll, 1998). 

Homestake Mining Company also diverts water from 

Spearfish Creek for two hydroelectric power plants; 

these flows are returned to Spearfish Creek below the 

loss zone. Substantial withdrawals for municipal 

supplies also are made from Rapid Creek.

HYDROLOGIC PROCESSES AND

CHARACTERISTICS

This section describes the characteristics of the 

ground-water and surface-water resources in the study 

area, including the response of ground water and 

streamflow to variations in hydrologic conditions and 

water-quality characteristics. A brief discussion of 

hydrologic processes relevant to the Black Hills area is 

first presented.

Hydrologic Processes

A schematic diagram illustrating hydrologic processes is presented in figure 24. Precipitation falling on 

the earth’s surface generally infiltrates into the soil 

horizon, unless the soil is saturated or the infiltration 

capacity is exceeded, in which case overland flow or 

direct runoff will occur. Some water may be returned 

from the soil horizon to the land surface through interflow, contributing to relatively short-term increases in 

streamflow. In the Black Hills area, where potential 

evaporation generally exceeds precipitation, most 

water is eventually returned to the atmosphere through 

evapotranspiration (ET). Water infiltrating beyond the 

root zone may eventually recharge ground-water systems; however, ground-water discharge (in the form of 

springflow or seepage) also may contribute to streamflow.

Figure 24. Schematic diagram illustrating hydrologic processes (modified from Driscoll and Carter, 2001).

Unsaturated

zone

Saturated zone

Water table

Perched

water table

Overland flow

Precipitation

Confining unit Alluvial deposits

Ground-water discharge to

streams

Overland flow

Depression

storage

Interflow

Infiltration

Infiltration

Interflow

Springflow

Evaporation

Precipitation

Evapotranspiration

Transpiration

Stream

channel

Soil horizon and

colluvial deposits

Confining unit Alluvial

deposits

Ground-water

discharge to

streams

Total runoff

Groundwater

outflow

Groundwater

inflow

Bedrock

aquifer
38 Hydrology of the Black Hills Area, South Dakota

In this report, the term runoff is used to include 

all means by which precipitation eventually contributes 

to streamflow. Direct runoff includes overland flow 

and that portion of interflow that arrives in stream 

channels relatively quickly. Base flow generally 

includes all ground water discharging to streams and 

also includes some interflow. Springflow is generally 

considered to be ground-water discharge that occurs in 

somewhat discrete and identifiable locations, as 

opposed to more general ground-water seepage. 

Streamflow is inclusive of runoff and also may include 

water from other sources such as diversions or well 

discharges.

Within this report, streamflow is most commonly 

expressed in units of cubic feet per second, but frequently is expressed in acre-feet per year (1.0 ft3/s 

= 724.46 acre-ft for a year consisting of 365.25 days). 

Units of acre-feet (1.0 ft over an acre, which is equivalent to 43,560 ft2

) are especially convenient for calculating annual yield (annual runoff per unit of area), 

which generally is expressed in inches.

Ground-Water Characteristics

Water-level trends and comparisons for the 

major aquifers in the study area are described in this 

section. In addition, water-quality characteristics for 

the major aquifers are described, and a brief summary 

for other aquifers is provided.

Water-Level Trends and Comparisons

Well hydrographs provide information regarding 

temporal water-level trends, comparisons between 

aquifers, and water-level response to climatic conditions. Hydrographs (by calendar year) for 49 wells are 

presented in this section; the location of these wells is 

shown in figure 25. On these hydrographs, solid lines 

indicate continuous records and dashed lines indicate 

periods with discontinuous records, which may be 

based only on periodic manual measurements in some 

cases. Hydrographs for 22 additional wells were presented by Driscoll, Bradford, and Moran (2000).

Temporal Trends

Temporal trends in water levels are examined for 

eight wells with relatively long-term records (fig. 26). 

Most of these wells are in locations that may be 

affected by withdrawals from production wells. The 

Hermosa South Inyan Kara well (fig. 26G), with a 

steady decline in water level of about 4 ft from 1983 to 

1998, is the only observation well in the Black Hills 

area that shows a steadily declining trend throughout its 

period of record. The Hermosa West Inyan Kara well 

(fig. 26F), which is located several miles farther north 

(fig. 25), does not show a similar decline.

The water level at the Redwater Minnelusa well 

(fig. 26A) shows a seasonal response to withdrawals 

for irrigation, but generally recovers each year. The 

water level at the Boulder Canyon Minnelusa well 

(fig. 26B) declined steadily during the 1980’s and early 

1990’s, but recovered during subsequent years. 

The Sioux Park Madison well (fig. 26E) shows 

response to increased production by the city of Rapid 

City from the Madison aquifer beginning in the late 

1980’s. Recovery occurs during winter months when 

production is reduced. An adjacent Minnelusa well 

shows no influence from production from the Madison 

aquifer; however, a decline during the 1990’s in the 

Cement Plant Minnelusa well (fig. 26C) may be related 

to the increased production from the Madison aquifer.

The Countryside Deadwood well (fig. 26D) is 

located southwest of Rapid City in an area where substantial production from the Deadwood aquifer occurs. 

Increasing demand in this area occasionally has caused 

water-supply shortages during recent periods of peak 

demand; however, long-term water-level declines are 

not apparent.

Comparisons Between Madison and Minnelusa Aquifers

In many locations, two or more observation 

wells are colocated. The most common colocated wells 

are paired Madison and Minnelusa wells, which can 

provide information regarding interactions between 

these aquifers. A variety of factors have potential to 

contribute to reduced competency of confining layers 

between the Madison and Minnelusa aquifers, which 

can result in hydraulic connection. Interactions 

between the Madison and Minnelusa aquifers were 

investigated by Naus and others (2001) and are discussed in more detail in a subsequent section of this 

report.
Ground-Water Characteristics 39

Figure 25. Location of observation wells for which hydrographs are presented.

N. Fork Rapid Cr

Belle Fourche

Reservoir

FOURCHE

Victoria

Rhoads Fork

Coolidge

Highland

Angostura

Reservoir

Castl e Cr

N. Fork Castle Cr

Hell

Canyon

Canyon

Red

Bear

Gulch

Creek

Crow

Sheridan

Lake

Hot Brook Canyon

Cox

Lake

Deerfield

Reservoir

Pactola

Reservoir

Indian Cr

Horse

Creek

Owl

BELLE

Creek

RIVER

REDWATER

R I VER

Creek

Cr

Little Spearfish

Spearfish

Whitewood

Creek

Creek

Bear

Butte

Elk

Elk

Creek

Creek

Creek

Boxelder

Rapid

Rapid

Creek

Creek

Spring

Creek

French

Creek

Creek

Creek

Grace

Creek

Creek

Creek

S. Fork

Gillette

S. Fork Rapid Cr

Battle

French

Beaver

Beaver

Creek

Creek

Creek

Creek

Creek

Fall R

Hat

Creek

Creek

Horsehead

CHEYENNE

RIVER

Cottonwood

Hay Creek

Bottom

False

Creek

Spokane

Lame

Johnny

Higgins

Beaver

Cr

Whitetail

Cr

Cr

Cr Cr

Gulch

Annie

Squaw

Deadwood

Creek

Alkali

Iron Cr

Elk

Little

Creek

Castle

Castle

Creek

Creek

Bear Gulch

Cr Strawberry

Boles

Canyon

Canyon

Redbird Canyon

Cold

Beaver

Spring

C s

reek

Creek

Whitewood

Spearfish

Saint

Onge

DEADWOOD

Lead

BELLE FOURCHE

Newell

STURGIS

Blackhawk

Piedmont

Tilford

Box Elder 

Hill City

Hermosa

CUSTER

HOT SPRINGS

Edgemont

Minnekahta

Tinton Central

City

Roubaix

Nemo

Vale

Nisland

Hayward

Keystone

Rochford

Pringle

Fairburn

Buffalo Gap

Dewey

Cascade

Springs

Igloo

Provo

Oral

Rockerville

RAPID CITY

LIMESTONE PLATEAU

 Wind Cave

National Park

Jewel Cave

National

Monument

Mt. Rushmore

National

Memorial

CUSTER

STATE

PARK

Wind

Cave

Harney

Peak

x

Ellsworth

Air Force

Base

BUTTE CO

LAWRENCE CO MEADE CO

PENNINGTON CO

CUSTER CO

FALL RIVER CO

WYOMING

SOUTH DAKOTA

18,19,20

 1

7,8

13

21,22

23

36,37

5,6

9,10 14,15

24,25

29,30 31,32

33,34

39,40

41,42

43,44,45

46,47 48,49

2,3,4

 11,12

38

35

16,17

26,27

28

18,19,20

 1

7,8

13

21,22

23

36,37

5,6

9,10 14,15

24,25

29,30 31,32

33,34

39,40

41,42

43,44,45

46,47 48,49

2,3,4

 11,12

38

35

16,17

26,27

28

0 10 20

0 10 20 MILES

KILOMETERS

OBSERVATION WELL--Symbol

 indicates aquifer designation.

 Number indicates map number

EXPLANATION

2

16

35

3

4

Madison

Minnelusa

Deadwood

Minnekahta

Inyan Kara

104o 45' 103o

30'

15' 103o

30'

44o

45'

15'

44o

45'

30'

43o

15'

OUTCROP OF MADISON LIME-

 STONE (from Strobel and

 others, 1999)

OUTCROP OF MINNELUSA

 FORMATION (from Strobel

 and others, 1999)

Base modified from U.S. Geological Survey digital data,

1:100,000, 1977, 1979, 1981, 1983, 1985

Rapid City, Office of City Engineer map, 1:18,000, 1996

Universal Transverse Mercator projection, zone 13
40 Hydrology of the Black Hills Area, South Dakota

Figure 26. Hydrographs illustrating temporal trends in ground-water levels. WATER LEVEL, IN FEET ABOVE SEA LEVEL

B

C

E

3,640

3,700

3,660

3,680

Boulder Canyon Minnelusa (site 13)

3,380

3,460

3,400

3,420

3,440

Cement Plant Minnelusa (site 23)

D

3,340

3,460

3,360

3,380

3,400

3,420

3,440

Sioux Park Minnelusa (site 32)

Sioux Park Madison (site 31)

A

3,460

3,540

3,480

3,500

3,520

Redwater Minnelusa (site 1)

3,500

3,420

3,440

3,460

3,480

Countryside Deadwood (site 28)

CALENDAR YEAR

1960 1965 1970 1975 1980 1985 1990 1995 1999
Ground-Water Characteristics 41

Hydrographs illustrating general similarities in 

water levels for some colocated Madison and Minnelusa wells are presented in figure 27. All of the wells 

are located where confined conditions exist in both 

aquifers. Hydraulic connection between the aquifers 

has been confirmed through aquifer testing (Greene, 

1993) for the City Quarry wells (fig. 27D), which have 

hydrographs that are nearly identical. Hydraulic connection in this area also has been confirmed by dye 

testing (Greene, 1997), which identified a Madison 

aquifer source for nearby City Springs (fig. 23) that 

discharges through the Minnelusa Formation.

Similarities in hydrographs do not necessarily 

indicate hydraulic connection between the aquifers. 

Hydrographs for the Spearfish Golf Course wells 

(fig. 27A) are very similar during 1995-98, but have 

little similarity prior to that period. Aquifer testing 

(Greene and others, 1999) provided no indication of 

hydraulic connection in the vicinity of these wells. 

Hydrographs for the Custer State Park (CSP) wells 

(fig. 27F) are nearly identical, and other pairs shown 

have general similarities. At most pairs of wells, 

hydraulic connection cannot be confirmed or refuted 

because aquifer testing has not been performed.

Distinct hydraulic separation between the 

Madison and Minnelusa aquifers is apparent for two 

well pairs (fig. 28) where water-level altitudes differ by 

about 500 to 600 ft in locations where unconfined 

(water-table) conditions occur. In both locations, the 

water table in the Minnelusa aquifer is much higher 

than that in the Madison aquifer, which also is not fully 

saturated. Both well pairs are located within or near the 

Minnelusa Formation outcrops (fig. 25) and measured 

water-level altitudes in the Minnelusa aquifer are 

higher than for most other observation wells in unconfined areas.

Figure 26. Hydrographs illustrating temporal trends in ground-water levels.—Continued WATER LEVEL, IN FEET ABOVE SEA LEVEL

CALENDAR YEAR

1960 1965 1970 1975 1980 1985 1990 1995 1999

G Hermosa South Inyan Kara (site 38)

F

3,300

3,360

3,320

3,340

3,320

3,380

3,340

3,360

Hermosa West Inyan Kara (site 35)
42 Hydrology of the Black Hills Area, South Dakota

Figure 27. Hydrographs illustrating general similarities in water levels for some colocated Madison/Minnelusa wells with 

confined conditions. WATER LEVEL, IN FEET ABOVE SEA LEVEL

CALENDAR YEAR

1984 1986 1988 1990 1992 1994 1996 1998

CALENDAR YEAR

1984 1986 1988 1990 1992 1994 1996 1998

A D

B E

C F

3,600

3,700

3,620

3,640

3,660

3,680 Spearfish Golf Course Madison (site 9)

Spearfish Golf Course Minnelusa (site 10)

Whitewood Madison (site 14)

Whitewood Minnelusa (site 15)

3,380

3,480

3,400

3,420

3,440

3,460

3,550

3,700

3,600

3,650

Tilford Madison (site 18)

Tilford Minnelusa (site 19)

Tilford Minnekahta (site 20)

3,420

3,500

3,440

3,460

3,480

City Quarry Madison (site 24)

City Quarry Minnelusa (site 25)

3,450

3,600

3,500

3,550

Reptile Gardens Madison (site 33)

Reptile Gardens Minnelusa (site 34)

3,660

3,720

3,680

3,700

CSP Airport Madison (site 39)

CSP Airport Minnelusa (site 40)

Figure 28. Hydrographs illustrating distinct hydraulic separation for two Madison/Minnelusa well pairs with unconfined 

conditions. WATER LEVEL, IN FEET ABOVE SEA LEVEL

CALENDAR YEAR CALENDAR YEAR

1984 1986 1988 1990 1992 1994 1996 1998 1984 1986 1988 1990 1992 1994 1996 1998

A B

3,600

4,400

3,800

4,000

4,200

Tinton Road Madison (site 7)

Tinton Road Minnelusa (site 8)

Boles Canyon Madison (site 36)

Boles Canyon Minnelusa (site 37)
Ground-Water Characteristics 43

Figure 29 shows hydrographs for other colocated 

Madison and Minnelusa wells, most of which are in 

locations with confined conditions (figs. 21 and 22). 

Most of these well pairs show distinct hydraulic separation between the aquifers, with hydraulic heads separated by as much as 100 to 150 ft. Hydraulic separation 

is consistently less than about 30 ft for three well pairs, 

however—the Frawley Ranch, Hell Canyon, and 

Minnekahta Junction wells (figs. 29B, 29E, and 29G, 

respectively). Periods of record for these wells may be 

insufficient to indicate similarity or dissimilarity of 

hydrograph shapes.

Hydraulic connection between aquifers does not 

necessarily mean hydrographs will be similar. The 

Madison and Minnelusa aquifers probably are connected hydraulically at Cleghorn and Jackson Springs 

(fig. 23), which are located within the outcrop of the 

Minnelusa Formation, but probably originate primarily 

from the Madison aquifer (Naus and others, 2001). 

Hydrographs for the Canyon Lake wells, which are 

located about one-quarter mile from the spring complex, show no indication of hydraulic connection, however (fig. 29D). Hydraulic head in the Minnelusa 

aquifer is about 50 to 60 ft lower than in the Madison 

aquifer in this area, indicating probable recharge from 

the Madison aquifer (Driscoll and Carter, 2001). The 

Minnelusa aquifer apparently is connected hydraulically to Rapid Creek at this location, as evidenced by a 

sharp water-level decline during a period when Canyon 

Lake was drained near the end of 1995.

Another observation that can be made from comparisons of hydrographs for paired wells is that the 

hydraulic head in the Madison aquifer equals or 

exceeds the hydraulic head in the Minnelusa aquifer in 

most locations where confined conditions occur. The 

Madison aquifer has the potential for higher hydraulic 

head than the Minnelusa aquifer because of generally 

higher altitude of recharge area for the Madison 

aquifer. An exception to this generality occurs along 

the northeastern flank of the Black Hills. The hydraulic 

head in the Minnelusa aquifer generally equals or 

exceeds that in the Madison aquifer for the Spearfish 

Golf Course wells (fig. 27A), the Whitewood wells 

(fig. 27B), and the Frawley Ranch wells (fig. 29B).

Comparisons for Other Aquifers

Hydrograph comparisons for colocated wells 

completed in other aquifers are presented in figure 30. 

Hydrographs for the Spearfish West Minnelusa and 

Minnekahta wells are shown in figure 30A. Hydrographs for the Minnekahta aquifer also are available for 

the Tilford wells (fig. 27C), State Line wells (fig. 29A), 

and 7-11 Ranch wells (fig. 29F). Many artesian springs 

emerge through the Minnekahta Limestone; thus, 

hydraulic connections with the underlying Madison 

and Minnelusa aquifers are possible. Hydrographs for 

the Minnekahta and Madison wells are very similar for 

the State Line wells, which are located about 3 mi 

south of a group of large artesian springs (fig. 23). 

Hydraulic heads in the Minnelusa and Minnekahta 

wells are quite similar in the 7-11 Ranch wells, which 

are located 3 mi west of Beaver Creek Springs.

Hydrographs for colocated Deadwood and 

Madison wells (fig. 30) are available for two locations. 

For the Cheyenne Crossing wells (fig. 30B), the water 

table in the Madison aquifer is about 250 ft higher than 

the water table in the Deadwood aquifer. For the Doty 

wells (fig. 30C), the Deadwood aquifer is confined, and 

hydraulic head is about 200 ft higher than in the Madison aquifer.

Responses to Climatic Conditions

Ground-water levels are directly affected by 

recharge rates that are influenced by annual precipitation amounts; however, numerous other factors can 

affect ground-water response. The timing and intensity 

of precipitation, along with evaporative factors such as 

temperature, humidity, wind speed, and solar radiation, 

can have a large effect on annual recharge. Streamflow 

losses (especially for the Madison and Minnelusa aquifers) also contribute to recharge. Ground-water levels 

also can be affected by well withdrawals, spring discharges, and various hydraulic properties of aquifers. 

Hydrographs for many wells in figures 26-30 show a 

distinct response to annual precipitation patterns 

(fig. 8); thus, other influences probably are relatively 

minor for many wells. Many of these wells with sufficient periods of record show short-term declines during 

the late 1980’s, with generally increasing water levels 

during the wetter conditions of the middle to late 

1990’s.

Water-level records are not available for the 

Black Hills area for the prolonged drought conditions 

that occurred during the 1930’s and late 1950’s. Cumulative precipitation deficits during these periods were 

more severe than for the short-term drought conditions 

that occurred during the late 1980’s (fig. 8). Recharge 

estimates for 1931-98 for the Madison and Minnelusa 

aquifers (Carter, Driscoll, and Hamade, 2001) indicate 

that recharge also was minimal during the 1930’s and 

late 1950’s; thus, water-level declines exceeding those 

of the late 1980’s probably occurred.
44 Hydrology of the Black Hills Area, South Dakota

Figure 29. Hydrographs illustrating generally separated water levels for some colocated Madison/Minnelusa wells. WATER LEVEL, IN FEET ABOVE SEA LEVEL

CALENDAR YEAR

1984 1986 1988 1990 1992 1994 1996 1998

CALENDAR YEAR

1984 1986 1988 1990 1992 1994 1996 1998

A E

B F

C G

D H

3,600

3,800

3,650

3,700

3,750

State Line Madison (site 2)

State Line Minnelusa (site 3)

State Line Minnekahta (site 4)

Frawley Ranch Madison (site 5)

Frawley Ranch Minnelusa (site 6)

3,510

3,560

3,520

3,530

3,540

3,550

3,450

3,650

3,500

3,550

3,600

Piedmont Madison (site 21)

Piedmont Minnelusa (site 22) 

3,340

3,440

3,360

3,380

3,400

3,420

Canyon Lake Madison (site 29)

Canyon Lake Minnelusa (site 30)

3,700

3,740

3,710

3,720

3,730

Hell Canyon Madison (site 41)

Hell Canyon Minnelusa (site 42)

3,400

3,700

3,500

3,600 7-11 Ranch Madison (site 43)

7-11 Ranch Minnelusa (site 44)

7-11 Ranch Minnekahta (site 45)

3,635

3,655

3,640

3,645

3,650

Minnekahta Junction Madison (site 46)

Minnekahta Junction Minnelusa (site 47)

Vets Home Madison (site 48)

Vets Home Minnelusa (site 49)

3,450

3,700

3,500

3,550

3,600

3,650
Ground-Water Characteristics 45

Hydrographs for the Inyan Kara wells (figs. 26F 

and G) show minimal response to climatic conditions. 

Hydrographs for other Inyan Kara wells that are not 

shown also show minimal response to climatic conditions (Driscoll, Bradford, and Moran, 2000).

All of the other aquifers show a wide range of 

water-level responses to climatic conditions, ranging 

from minimal response to several tens of feet. The 

largest overall water-level change is for the Reptile 

Gardens Madison well (fig. 27E), which increased by 

about 110 ft during 1990-98. Increases of about 80 ft 

have been recorded for the Tilford Madison and 

Minnelusa wells (fig. 27C).

Driscoll and Carter (2001) noted that for the 

Madison and Minnelusa aquifers, the smallest waterlevel fluctuations occur in the extreme southern Black 

Hills. Smaller recharge than in other areas probably is 

a contributing factor. Another factor may be large 

storage capacity in unconfined parts of the aquifers, 

which are especially extensive in the southern Black 

Hills (figs. 21 and 22). Caves, which are especially 

prevalent in the Madison aquifer, probably are more 

common in the southern Black Hills than in other areas 

and can provide large storage capacity .

Water Quality

This section includes a summary of waterquality characteristics for the major aquifers and 

selected minor aquifers in the Black Hills area. More 

detailed descriptions of ground-water quality are presented by Williamson and Carter (2001), who considered water-quality data collected for the Black Hills 

Hydrology Study and other studies from October 1, 

1930, to September 30, 1998. A brief discussion of the 

susceptibility of aquifers to contamination also is presented, as well as a summary of water quality relative 

to water use. Table 4 describes the significance of 

selected properties and constituents and any related 

U.S. Environmental Protection Agency (USEPA) 

water-quality standards for drinking water.

Maximum Contaminant Levels (MCL’s) are 

established for contaminants that, if present in drinking 

water, may cause adverse human health effects; MCL’s 

are enforceable health-based standards (U.S. Environmental Protection Agency, 1994a). Secondary Maximum Contaminant Levels (SMCL’s) are established 

for contaminants that can adversely affect the taste, 

odor, or appearance of water and may result in discontinuation of use of the water; SMCL’s are nonenforceable, generally non-health-based standards that are 

related to the aesthetics of water use (U.S. Environmental Protection Agency, 1994a). Action levels, 

which are concentrations that determine whether 

treatment requirements may be necessary (U.S. 

Environmental Protection Agency, 1997), have been 

established for copper and lead. 

Concentrations of constituents were compared 

by Williamson and Carter (2001) to drinking-water 

standards set by the USEPA. Although USEPA standards apply only to public-water supplies, individuals 

using water from private wells should be aware of the 

potential health risks associated with drinking water 

that exceeds drinking-water standards.

Figure 30. Hydrographs for colocated Minnelusa/Minnekahta 

and Deadwood/Madison wells. WATER LEVEL, IN FEET ABOVE SEA LEVEL

CALENDAR YEAR

1984 1986 1988 1990 1992 1994 1996 1998

A

B

C

Spearfish West Minnelusa (site 11)

Spearfish West Minnekahta (site 12)

3,520

3,620

3,540

3,560

3,580

3,600

Cheyenne Crossing Madison (site 17)

Cheyenne Crossing Deadwood (site 16)

5,500

5,900

5,600

5,700

5,800

Doty Deadwood (site 26)

Doty Madison (site 27)

3,800

4,100

3,900

4,000
46 Hydrology of the Black Hills Area, South Dakota

Table 4. Water-quality criteria, standards, or recommended limits for selected properties and constituents 

[All standards are from U.S. Environmental Protection Agency (1994a) unless noted. MCL, Maximum Contaminant Level; SMCL, Secondary Maximum 

Contaminant Level; USEPA, U.S. Environmental Protection Agency; mg/L, milligrams per liter; μS/cm, microsiemens per centimeter at 25 degrees Celsius; 

μg/L, micrograms per liter; pCi/L, picocuries per liter; --, no limit established]

Constituent

or property Standard Significance

Specific conductance -- A measure of the ability of water to conduct an electrical current; varies with temperature. 

Magnitude depends on concentration, kind, and degree of ionization of dissolved constituents; can be used to determine the approximate concentration of dissolved solids. Values 

are reported in microsiemens per centimeter at 25°Celsius.

pH 6.5-8.5 units

SMCL

A measure of the hydrogen ion concentration; pH of 7.0 indicates a neutral solution, pH 

values smaller than 7.0 indicate acidity, pH values larger than 7.0 indicate alkalinity. 

Water generally becomes more corrosive with decreasing pH; however, excessively 

alkaline water also may be corrosive.

Temperature -- Affects the usefulness of water for many purposes. Generally, users prefer water of uniformly low temperature. Temperature of ground water tends to increase with increasing 

depth to the aquifer.

Dissolved oxygen -- Required by higher forms of aquatic life for survival. Measurements of dissolved oxygen 

are used widely in evaluations of the biochemistry of streams and lakes. Oxygen is supplied to ground water through recharge and by movement of air through unsaturated 

material above the water table (Hem, 1985).

Carbon dioxide -- Important in reactions that control the pH of natural waters. 

Hardness and noncarbonate hardness (as 

mg/L CaCO3)

-- Related to the soap-consuming characteristics of water; results in formation of scum when 

soap is added. May cause deposition of scale in boilers, water heaters, and pipes. Hardness contributed by calcium and magnesium, bicarbonate and carbonate mineral species 

in water is called carbonate hardness; hardness in excess of this concentration is called 

noncarbonate hardness. Water that has a hardness less than 61 mg/L is considered soft; 

61-120 mg/L, moderately hard; 121-180 mg/L, hard; and more than 180 mg/L, very hard 

(Heath, 1983).

Alkalinity -- A measure of the capacity of unfiltered water to neutralize acid. In almost all natural waters 

alkalinity is produced by the dissolved carbon dioxide species, bicarbonate and carbonate. Typically expressed as mg/L CaCO3.

Dissolved solids 500 mg/L

SMCL

The total of all dissolved mineral constituents, usually expressed in milligrams per liter. The 

concentration of dissolved solids may affect the taste of water. Water that contains more 

than 1,000 mg/L is unsuitable for many industrial uses. Some dissolved mineral matter is 

desirable, otherwise the water would have no taste. The dissolved solids concentration 

commonly is called the water’s salinity and is classified as follows: fresh, 0-1,000 mg/L; 

slightly saline, 1,000-3,000 mg/L; moderately saline, 3,000-10,000 mg/L; very saline, 

10,000-35,000 mg/L; and briny, more than 35,000 mg/L (Heath, 1983).

Calcium plus magnesium-- Cause most of the hardness and scale-forming properties of water (see hardness).

Sodium plus potassium -- Large concentrations may limit use of water for irrigation and industrial use and, in combination with chloride, give water a salty taste. Abnormally large concentrations may indicate natural brines, industrial brines, or sewage.

Sodium-adsorption ratio 

(SAR)

-- A ratio used to express the relative activity of sodium ions in exchange reactions with soil. 

Important in irrigation water; the greater the SAR, the less suitable the water for irrigation.

Bicarbonate -- In combination with calcium and magnesium forms carbonate hardness.
Ground-Water Characteristics 47

Sulfate 250 mg/L

SMCL

Sulfates of calcium and magnesium form hard scale. Large concentrations of sulfate have a 

laxative effect on some people and, in combination with other ions, give water a bitter 

taste.

Chloride 250 mg/L

SMCL

Large concentrations increase the corrosiveness of water and, in combination with sodium, 

give water a salty taste.

Fluoride 4.0 mg/L

MCL

2.0 mg/L

SMCL

Reduces incidence of tooth decay when optimum fluoride concentrations present in water 

consumed by children during the period of tooth calcification. Potential health effects of 

long-term exposure to elevated fluoride concentrations include dental and skeletal fluorosis (U.S. Environmental Protection Agency, 1994b).

Nitrite (mg/L as N) 1.0 mg/L

MCL

Commonly formed as an intermediate product in bacterially mediated nitrification and denitrification of ammonia and other organic nitrogen compounds. An acute health concern 

at certain levels of exposure. Nitrite typically occurs in water from fertilizers and is found 

in sewage and wastes from humans and farm animals. Concentrations greater than 

1.0 mg/L, as nitrogen, may be injurious to pregnant women, children, and the elderly.

Nitrite plus nitrate 

(mg/L as N)

10 mg/L

MCL

Concentrations greater than local background levels may indicate pollution by feedlot runoff, sewage, or fertilizers. Concentrations greater than 10 mg/L, as nitrogen, may be 

injurious to pregnant women, children, and the elderly.

Ammonia -- Plant nutrient that can cause unwanted algal blooms and excessive plant growth when 

present at elevated levels in water bodies. Sources include decomposition of animal and 

plant proteins, agricultural and urban runoff, and effluent from waste-water treatment 

plants.

Phosphorus, orthophosphate-- Dense algal blooms or rapid plant growth can occur in waters rich in phosphorus. A limiting 

nutrient for eutrophication since it is typically in shortest supply. Sources are human and 

animal wastes and fertilizers.

Arsenic 1

10 μg/L

MCL

No known necessary role in human or animal diet, but is toxic. A cumulative poison that is 

slowly excreted. Can cause nasal ulcers; damage to the kidneys, liver, and intestinal 

walls; and death. Recently suspected to be a carcinogen (Garold Carlson, U.S. Environmental Protection Agency, written commun., 1998).

Barium 2,000 μg/L

MCL

Toxic; used in rat poison. In moderate to large concentrations can cause death; smaller concentrations can cause damage to the heart, blood vessels, and nerves.

Boron -- Essential to plant growth, but may be toxic to crops when present in excessive concentrations in irrigation water. Sensitive plants show damage when irrigation water contains 

more than 670 μg/L and even tolerant plants may be damaged when boron exceeds 

2,000 μg/L. The recommended limit is 750 μg/L for long-term irrigation on sensitive 

crops (U.S. Environmental Protection Agency, 1986).

Cadmium 5 μg/L

MCL

A cumulative poison; very toxic. Not known to be either biologically essential or beneficial. 

Believed to promote renal arterial hypertension. Elevated concentrations may cause liver 

and kidney damage, or even anemia, retarded growth, and death.

Copper 1,300 μg/L

(action level)

Essential to metabolism; copper deficiency in infants and young animals results in nutritional anemia. Large concentrations of copper are toxic and may cause liver damage. 

Moderate levels of copper (near the action level) can cause gastro-intestinal distress. If 

more than 10 percent of samples at the tap of a public water system exceed 1,300 μg/L, 

the USEPA requires treatment to control corrosion of plumbing materials in the system.

Table 4. Water-quality criteria, standards, or recommended limits for selected properties and constituents–Continued

[All standards are from U.S. Environmental Protection Agency (1994a) unless noted. MCL, Maximum Contaminant Level; SMCL, Secondary Maximum 

Contaminant Level; USEPA, U.S. Environmental Protection Agency; mg/L, milligrams per liter; μS/cm, microsiemens per centimeter at 25 degrees Celsius; 

μg/L, micrograms per liter; pCi/L, picocuries per liter; --, no limit established]

Constituent

or property Standard Significance
48 Hydrology of the Black Hills Area, South Dakota

Iron 300 μg/L

SMCL

Forms rust-colored sediment; stains laundry, utensils, and fixtures reddish brown. Objectionable for food and beverage processing. Can promote growth of certain kinds of 

bacteria that clog pipes and well openings.

Lead 15 μg/L

(action level)

A cumulative poison; toxic in small concentrations. Can cause lethargy, loss of appetite, 

constipation, anemia, abdominal pain, gradual paralysis in the muscles, and death. If 1 in 

10 samples of a public supply exceed 15 μg/L, the USEPA recommends treatment to 

remove lead and monitoring of the water supply for lead content (U.S. Environmental 

Protection Agency, 1991).

Lithium -- Reported as probably beneficial in small concentrations (250-1,250 μg/L). Reportedly may 

help strengthen the cell wall and improve resistance to genetic damage and to disease. 

Lithium salts are used to treat certain types of psychosis.

Manganese 50 μg/L

SMCL

Causes gray or black stains on porcelain, enamel, and fabrics. Can promote growth of certain kinds of bacteria that clog pipes and wells.

Mercury (inorganic) 2 μg/L

MCL

No known essential or beneficial role in human or animal nutrition. Liquid metallic mercury and elemental mercury dissolved in water are comparatively nontoxic, but some 

mercury compounds, such as mercuric chloride and alkyl mercury, are very toxic. 

Elemental mercury is readily alkylated, particularly to methyl mercury, and concentrated 

by biological activity. Potential health effects of exposure to some mercury compounds 

in water include severe kidney and nervous system disorders (U.S. Environmental 

Protection Agency, 1994b).

Nickel -- Very toxic to some plants and animals. Toxicity for humans is believed to be very minimal.

Selenium 50 μg/L

MCL

Essential to human and animal nutrition in minute concentrations, but even a moderate 

excess may be harmful or potentially toxic if ingested for a long time (Callahan and 

others, 1979). Potential human health effects of exposure to elevated selenium concentrations include liver damage (U.S. Environmental Protection Agency, 1994b).

Silver 100 μg/L

SMCL

Causes permanent bluish darkening of the eyes and skin (argyria). Where found in water is 

almost always from pollution or by intentional addition. Silver salts are used in some 

countries to sterilize water supplies. Toxic in large concentrations.

Strontium -- Importance in human and animal nutrition is not known, but believed to be essential. Toxicity believed very minimal—no more than that of calcium.

Zinc 5,000 μg/L

SMCL

Essential and beneficial in metabolism; its deficiency in young children or animals will 

retard growth and may decrease general body resistance to disease. Seems to have no ill 

effects even in fairly large concentrations (20,000-40,000 mg/L), but can impart a metallic taste or milky appearance to water. Zinc in drinking water commonly is derived from 

galvanized coatings of piping.

Gross alpha-particle 

activity

15 pCi/L

MCL

The measure of alpha-particle radiation present in a sample. A limit is placed on gross 

alpha-particle activity because it is impractical at the present time to identify all alphaparticle-emitting radionuclides due to analytical costs. Gross alpha-particle activity is a 

radiological hazard. The 15 pCi/L standard also includes radium-226, a known carcinogen, but excludes any uranium or radon that may be present in the sample. Thorium-230 

radiation contributes to gross alpha-particle activity.

Beta-particle and 

photon activity

(formerly manmade 

radionuclides)

4 millirem/yr

MCL

(under review)

The measure of beta-particle radiation present in a sample. Gross beta-particle activity is a 

radiological hazard. See strontium-90 and tritium.

Table 4. Water-quality criteria, standards, or recommended limits for selected properties and constituents–Continued

[All standards are from U.S. Environmental Protection Agency (1994a) unless noted. MCL, Maximum Contaminant Level; SMCL, Secondary Maximum 

Contaminant Level; USEPA, U.S. Environmental Protection Agency; mg/L, milligrams per liter; μS/cm, microsiemens per centimeter at 25 degrees Celsius; 

μg/L, micrograms per liter; pCi/L, picocuries per liter; --, no limit established]

Constituent

or property Standard Significance
Ground-Water Characteristics 49

Radium-226 & 228 

combined

5 pCi/L

MCL

Radium locates primarily in bone; however, inhalation or ingestion may result in lung 

cancer. Radium-226 is a highly radioactive alkaline-earth metal that emits alpha-particle 

radiation. It is the longest lived of the four naturally occurring isotopes of radium and is a 

disintegration product of uranium-238. Concentrations of radium in most natural waters 

are usually less than 1.0 pCi/L (Hem, 1985).

Radon2 300 or 4,000 

pCi/L

proposed MCL

Inhaled radon is known to cause lung cancer (MCL for radon in indoor air is 4 pCi/L). 

Ingested radon also is believed to cause cancer. A radon concentration of 1,000 pCi/L in 

water is approximately equal to 1 pCi/L in air. The ultimate source of radon is the radioactive decay of uranium. Radon-222 has a half-life of 3.8 days and is the only radon isotope of importance in the environment (Hem, 1985).

Strontium-90

(contributes to betaparticle and photon 

activity)

Gross betaparticle activity

(4 millirem/yr)

MCL

Strontium-90 is one of 12 unstable isotopes of strontium known to exist. It is a product of 

nuclear fallout and is known to cause adverse human health affects. Strontium-90 is a 

bone seeker and a relatively long-lived beta emitter with a half-life of 28 years. The 

USEPA has calculated that an average annual concentration of 8 pCi/L will produce a 

total body or organ dose of 4 millirem/yr (U.S. Environmental Protection Agency, 1997).

Thorium-230

(contributes to gross 

alpha-particle 

activity)

15 pCi/L

MCL

Thorium-230 is a product of natural radioactive decay when uranium-234 emits alphaparticle radiation. Thorium-230 also is a radiological hazard because it is part of the 

uranium-238 decay series and emits alpha-particle radiation through its own natural 

decay to become radium-226. The half-life of thorium-230 is about 80,000 years.

Tritium (3H)

(contributes to betaparticle and photon 

activity)

Gross betaparticle activity

(4 millirem/yr)

MCL

Tritium occurs naturally in small amounts in the atmosphere, but largely is the product of 

nuclear weapons testing. Tritium can be incorporated into water molecules that reach the 

Earth’s surface as precipitation. Tritium emits low energy beta particles and is relatively 

short-lived with a half-life of about 12.4 years. The USEPA has calculated that a concentration of 20,000 pCi/L will produce a total body or organ dose of 4 millirem/yr (CFR 40 

Subpart B 141.16, revised July 1997, p. 296).

Uranium 30 μg/L

MCL

(under review)

Uranium is a chemical and radiological hazard and carcinogen. It emits alpha-particle radiation through natural decay. It is a hard, heavy, malleable metal that can be present in 

several oxidation states. Generally, the more oxidized states are more soluble. Uranium238 and uranium-235, which occur naturally, account for most of the radioactivity in 

water. Uranium concentrations range between 0.1 and 10 μg/L in most natural waters.

1

USEPA currently is implementing a revised MCL for arsenic from 50 to 10 μg/L; public-water systems must meet the revised MCL by January 

2006 (U.S. Environmental Protection Agency, 2001). 2USEPA currently is working to set an MCL for radon in water. The proposed standards are 4,000 pCi/L for States that have an active indoor air program and 300 pCi/L for States that do not have an active indoor air program (Garold Carlson, U.S. Environmental Protection Agency, oral commun., 

1999). At this time, it is not known whether South Dakota will participate in an active indoor air program (Darron Busch, South Dakota Department of 

Environment and Natural Resources, oral commun., 1999).

Table 4. Water-quality criteria, standards, or recommended limits for selected properties and constituents–Continued

[All standards are from U.S. Environmental Protection Agency (1994a) unless noted. MCL, Maximum Contaminant Level; SMCL, Secondary Maximum 

Contaminant Level; USEPA, U.S. Environmental Protection Agency; mg/L, milligrams per liter; μS/cm, microsiemens per centimeter at 25 degrees Celsius; 

μg/L, micrograms per liter; pCi/L, picocuries per liter; --, no limit established]

Constituent

or property Standard Significance
50 Hydrology of the Black Hills Area, South Dakota

General Characteristics for Major Aquifers

A summary of water-quality characteristics from 

Williamson and Carter (2001) for the major aquifers in 

the study area (Deadwood, Madison, Minnelusa, 

Minnekahta, and Inyan Kara aquifers) is presented in 

this section. Characteristics for the Precambrian 

aquifer also are included in this section because 

numerous wells are completed in this aquifer in the 

crystalline core of the Black Hills. 

Most pH values for the major aquifers are within 

the specified range for the SMCL (6.5 to 8.5 standard 

units). About 13 percent of the samples from wells 

completed in Precambrian rocks had pH values less 

than the lower limit specified for the SMCL, which 

indicates acidity. In general, pH values are lower in 

wells completed in Precambrian rocks than in the other 

major aquifers, which is indicative of a unit containing 

little carbonate material. 

Water temperatures generally increase with well 

depth. The deepest wells in the study area are completed in the Madison aquifer; thus, measured temperatures in the Madison aquifer generally are the warmest 

of the major aquifers. The Madison aquifer is the 

primary source of water to warm artesian springs in the 

southern Black Hills, where water temperatures may be 

influenced by factors other than aquifer depth (Whalen, 

1994). 

Williamson and Carter (2001) quantified relations between dissolved solids and specific conductance concentrations for the major aquifers. The r2

(coefficient of determination) values are high for all of 

the major aquifers (fig. 31); thus, the equations provided could be used confidently for estimating dissolved solids concentrations from specific conductance 

measurements.

Specific conductance generally is low in water 

from the Precambrian, Deadwood, and Minnekahta 

aquifers. Dissolved constituents tend to increase with 

residence time as indicated by the general increase in 

specific conductance in the Madison aquifer with distance from the outcrop (fig. 32). Generally, water from 

the Inyan Kara aquifer is high in specific conductance 

even in some outcrop areas and is higher in specific 

conductance than the other major aquifers due to 

greater amounts of shale within the Inyan Kara Group. 

Water obtained from shales may contain rather high 

concentrations of dissolved solids (Hem, 1985) and, 

hence, high specific conductance.

Geologic units that contain little carbonate 

material, such as the Precambrian rocks, generally contain water with lower carbonate hardness and alkalinity 

than geologic units that are composed primarily of carbonate rocks. Water in the Madison, Minnelusa, and 

Minnekahta aquifers generally is hard to very hard 

because these units consist primarily of carbonate 

rocks. Water in the Deadwood aquifer also is hard to 

very hard because this unit consists primarily of sandstone with a calcium carbonate cement. The Inyan Kara 

aquifer may yield soft water, with hardness generally 

decreasing with increasing distance from the outcrop 

(fig. 33). Although concentrations of dissolved solids 

in the Inyan Kara aquifer actually increase with 

increasing distance from the outcrop, hardness 

decreases because calcium and bicarbonate are 

replaced by sodium and sulfate as water moves downgradient.

In the Black Hills area, water from the major 

aquifers generally is low in dissolved solids in and near 

outcrop areas. The Madison, Minnelusa, and Inyan 

Kara aquifers may yield slightly saline water (dissolved solids concentrations between 1,000 and 

3,000 mg/L) at distance from the outcrops, especially 

in the southern Black Hills. The water in these aquifers 

generally is highly mineralized outside of the Black 

Hills area, as previously described and shown in 

figure 17 for aquifers in the Paleozoic units.

Many of the major aquifers yield a calcium 

bicarbonate type water in and near outcrop areas, with 

concentrations of sodium, chloride, and sulfate 

increasing with distance from outcrops. High concentrations of sodium, chloride, and sulfate occur in the 

Madison aquifer (fig. 34) in the southwestern part of 

the study area relative to the rest of the study area. 

These high concentrations could be due to long residence times, long flowpaths associated with regional 

flow from the west (Wyoming), or greater amounts of 

evaporite minerals, such as anhydrite and gypsum, 

available for dissolution (Naus and others, 2001). In the 

southern part of the study area, the common-ion chemistry of the water in the Minnelusa aquifer also is characterized by higher concentrations of sodium and 

chloride (fig. 35). The high chloride concentrations in 

this area could reflect hydraulic connection between 

the Madison and Minnelusa aquifers (Naus and others, 

2001). The dissolution of evaporite minerals and long 

residence time also are possible explanations for the 

occurrence of this water type in the Minnelusa aquifer 

(Naus and others, 2001).
Ground-Water Characteristics 51

Figure 31. Relations between dissolved solids and specific conductance for the major aquifers.

0 1,500 500 1,000

0

800

200

400

600

Precambrian aquifer

0 4,000 1,000 2,000 3,000

0

2,000

500

1,000

1,500

DISSOLVED SOLIDS (S), IN MILLIGRAMS PER LITER

0 5,000 1,000 2,000 3,000 4,000

0

4,000

1,000

2,000

3,000

0 4,000 1,000 2,000 3,000

SPECIFIC CONDUCTANCE (K),

IN MICROSIEMENS PER CENTIMETER

0

2,500

500

1,000

1,500

2,000

0 6,000 1,000 2,000 3,000 4,000 5,000

SPECIFIC CONDUCTANCE (K),

IN MICROSIEMENS PER CENTIMETER

0

4,000

1,000

2,000

3,000

Madison aquifer

S = 0.6091K - 3.73

r

2 = 0.98

N = 91

S = 0.6151K - 14.42

r

2 = 0.91

N = 39

0 1,000 200 400 600 800

0

500

100

200

300

400

Deadwood aquifer

Minnelusa aquifer

S = 1.0070K - 215.09

r

2 = 0.98

N = 159

Minnekahta aquifer Inyan Kara aquifer

S = 0.8860K - 177.62

r

2 = 0.99

N = 25

S = 0.7842K - 98.49

r

2 = 0.95

N = 85

S = 0.5792K - 1.93

r

2 = 0.97

N = 33
52 Hydrology of the Black Hills Area, South Dakota

Figure 32. Distribution of specific conductance in the Madison aquifer (modified from Williamson and Carter, 2001).

BUTTE CO

LAWRENCE CO MEADE CO

PENNINGTON CO

CUSTER CO

FALL RIVER CO

WYOMING

SOUTH DAKOTA

N. Fork Rapid Cr

Belle Fourche

Reservoir

FOURCHE

Victoria

Spring

Rhoads Fork

Coolidge

Highland

Angostura

Reservoir

Castl e Cr

N. Fork Castle Cr

Hell

Canyon

Canyon

Red

Bear

Gulch

Creek

Crow

Sheridan

Lake

Hot Brook Canyon

Cox

Lake

Deerfield

Reservoir

Pactola

Reservoir

Indian Cr

Horse

Creek

Owl

BELLE

Creek

RIVER

REDWATER

R I VER

Creek

Cr

Little Spearfish

Spearfish

Creek

Spearfish

Whitewood

Creek

Creek

Bear

Butte

Elk

Elk

Creek

Creek

Creek

Boxelder

Rapid

Rapid

Creek

Creek

Creek

Spring

Creek

French

Creek

Creek

Creek

Grace

Creek

Creek

Creek

S. Fork

Gillette

S. Fork Rapid Cr

Battle

French

Beaver

Beaver

Creek

Creek

Creek

Creek

Creek

Fall R

Hat

Creek

Creek

Horsehead

CHEYENNE

RIVER

Cottonwood

Hay Creek

Bottom

False

Creek

Spokane

Lame

Johnny

Higgins

Beaver

Cr

Whitetail

Cr

Cr

Cr Cr

Gulch

Annie

Squaw

Deadwood

Creek

Alkali

Iron Cr

Elk

Little

Creek

Castle

Castle

Creek

Creek

Bear Gulch

Cr Strawberry

Boles

Canyon

Canyon

Redbird Canyon

Cold

Beaver

Spring

C s

reek

Creek

Whitewood

Spearfish

Saint

Onge

DEADWOOD

Lead

BELLE FOURCHE

Newell

STURGIS

Blackhawk

Piedmont

Tilford

Box Elder 

Hill City

Hermosa

CUSTER

HOT SPRINGS

Edgemont

Minnekahta

Tinton Central

City

Roubaix

Nemo

Vale

Nisland

Hayward

Keystone

Rochford

Pringle

Fairburn

Buffalo Gap

Dewey

Cascade

Springs

Igloo

Provo

Oral

Rockerville

RAPID CITY

LIMESTONE PLATEAU

 Wind Cave

National Park

Jewel Cave

National

Monument

Mt. Rushmore

National

Memorial

CUSTER

STATE

PARK

Wind

Cave

Harney

Peak

x

Ellsworth

Air Force

Base

0 10 20

0 10 20 MILES

KILOMETERS

EXPLANATION

OUTCROP OF MADISON LIME-

 STONE (from Strobel and

 others, 1999)

MADISON LIMESTONE ABSENT

 (from Carter and Redden,

 1999d)

Less than 500

500 to 1,000

1,000 to 1,500

Greater than 1,500

SPECIFIC CONDUCTANCE OF

 SAMPLE, IN MICROSIEMENS

 PER CENTIMETER AT 25

 DEGREES CELSIUS--Circle

 size increases with increasing

 concentrations

104o 45' 103o

30'

15' 103o

30'

44o

45'

15'

44o

45'

30'

43o

15'

Base modified from U.S. Geological Survey digital data,

1:100,000, 1977, 1979, 1981, 1983, 1985

Rapid City, Office of City Engineer map, 1:18,000, 1996

Universal Transverse Mercator projection, zone 13
Ground-Water Characteristics 53

Figure 33. Distribution of hardness in the Inyan Kara aquifer (modified from Williamson and Carter, 2001).

N. Fork Rapid Cr

Belle Fourche

Reservoir

FOURCHE

Victoria

Spring

Rhoads Fork

Coolidge

Highland

Angostura

Reservoir

Castl e Cr

N. Fork Castle Cr

Hell

Canyon

Canyon

Red

Bear

Gulch

Creek

Crow

Sheridan

Lake

Hot Brook Canyon

Cox

Lake

Deerfield

Reservoir

Pactola

Reservoir

Indian Cr

Horse

Creek

Owl

BELLE

Creek

RIVER

REDWATER

R I VER

Creek

Cr

Little Spearfish

Spearfish

Creek

Spearfish

Whitewood

Creek

Creek

Bear

Butte

Elk

Elk

Creek

Creek

Creek

Boxelder

Rapid

Rapid

Creek

Creek

Creek

Spring

Creek

French

Creek

Creek

Creek

Grace

Creek

Creek

Creek

S. Fork

Gillette

S. Fork Rapid Cr

Battle

French

Beaver

Beaver

Creek

Creek

Creek

Creek

Creek

Fall R

Hat

Creek

Creek

Horsehead

CHEYENNE

RIVER

Cottonwood

Hay Creek

Bottom

False

Creek

Spokane

Lame

Johnny

Higgins

Beaver

Cr

Whitetail

Cr

Cr

Cr Cr

Gulch

Annie

Squaw

Deadwood

Creek

Alkali

Iron Cr

Elk

Little

Creek

Castle

Castle

Creek

Creek

Bear Gulch

Cr Strawberry

Boles

Canyon

Canyon

Redbird Canyon

Cold

Beaver

Spring

C s

reek

Creek

Whitewood

Spearfish

Saint

Onge

DEADWOOD

Lead

BELLE FOURCHE

Newell

STURGIS

Blackhawk

Piedmont

Tilford

Box Elder 

Hill City

Hermosa

CUSTER

HOT SPRINGS

Edgemont

Minnekahta

Tinton Central

City

Roubaix

Nemo

Vale

Nisland

Hayward

Keystone

Rochford

Pringle

Fairburn

Buffalo Gap

Dewey

Cascade

Springs

Igloo

Provo

Oral

Rockerville

RAPID CITY

LIMESTONE PLATEAU

 Wind Cave

National Park

Jewel Cave

National

Monument

Mt. Rushmore

National

Memorial

CUSTER

STATE

PARK

Wind

Cave

Harney

Peak

x

Ellsworth

Air Force

Base

BUTTE CO

LAWRENCE CO MEADE CO

PENNINGTON CO

CUSTER CO

FALL RIVER CO

WYOMING

SOUTH DAKOTA

0 10 20

0 10 20 MILES

KILOMETERS

EXPLANATION

Very hard (greater than 180)

WATER HARDNESS, IN

 MILLIGRAMS PER LITER

Hard (121 to 180)

Moderately hard (61 to 121)

Soft (less than 61)

WELL COMPLETED IN INYAN

 KARA AQUIFER FOR WHICH

 THERE IS A HARDNESS

 ANALYSIS

OUTCROP OF INYAN KARA

 GROUP (from Strobel and

 others, 1999)

INYAN KARA GROUP ABSENT

 (from Carter and Redden,

 1999a)

104o 45' 103o

30'

15' 103o

30'

44o

45'

15'

44o

45'

30'

43o

15'

Base modified from U.S. Geological Survey digital data,

1:100,000, 1977, 1979, 1981, 1983, 1985

Rapid City, Office of City Engineer map, 1:18,000, 1996

Universal Transverse Mercator projection, zone 13
54 Hydrology of the Black Hills Area, South Dakota

Figure 34. Stiff diagrams (Stiff, 1951) showing the distribution of common-ion chemistry in the Madison aquifer (from

Naus and others, 2001).

N. Fork Rapid Cr

Belle Fourche

Reservoir

FOURCHE

Victoria

Spring

Rhoads Fork

Coolidge

Highland

Angostura

Reservoir

Castl e Cr

N. Fork Castle Cr

Hell

Canyon

Canyon

Red

Bear

Gulch

Creek

Crow

Sheridan

Lake

Hot Brook Canyon

Cox

Lake

Deerfield

Reservoir

Pactola

Reservoir

Indian Cr

Horse

Creek

Owl

BELLE

Creek

RIVER

REDWATER

R I VER

Creek

Cr

Little Spearfish

Spearfish

Creek

Spearfish

Whitewood

Creek

Creek

Bear

Butte

Elk

Elk

Creek

Creek

Creek

Boxelder

Rapid

Rapid

Creek

Creek

Creek

Spring

Creek

French

Creek

Creek

Creek

Grace

Creek

Creek

Creek

S. Fork

Gillette

S. Fork Rapid Cr

Battle

French

Beaver

Beaver

Creek

Creek

Creek

Creek

Creek

Fall R

Hat

Creek

Creek

Horsehead

CHEYENNE

RIVER

Cottonwood

Hay Creek

Bottom

False

Creek

Spokane

Lame

Johnny

Higgins

Beaver

Cr

Whitetail

Cr

Cr

Cr Cr

Gulch

Annie

Squaw

Deadwood

Creek

Alkali

Iron Cr

Elk

Little

Creek

Castle

Castle

Creek

Creek

Bear Gulch

Cr Strawberry

Boles

Canyon

Canyon

Redbird Canyon

Cold

Beaver

Spring

C s

reek

Creek

Whitewood

Spearfish

Saint

Onge

DEADWOOD

Lead

BELLE FOURCHE

Newell

STURGIS

Blackhawk

Piedmont

Tilford

Box Elder 

Hill City

Hermosa

CUSTER

HOT SPRINGS

Edgemont

Minnekahta

Tinton Central

City

Roubaix

Nemo

Vale

Nisland

Hayward

Keystone

Rochford

Pringle

Fairburn

Buffalo Gap

Dewey

Cascade

Springs

Igloo

Provo

Oral

Rockerville

RAPID CITY

LIMESTONE PLATEAU

 Wind Cave

National Park

Jewel Cave

National

Monument

Mt. Rushmore

National

Memorial

CUSTER

STATE

PARK

Wind

Cave

Harney

Peak

x

Ellsworth

Air Force

Base

BUTTE CO

LAWRENCE CO MEADE CO

PENNINGTON CO

CUSTER CO

FALL RIVER CO

WYOMING

SOUTH DAKOTA

0 10 20

0 10 20 MILES

KILOMETERS

EXPLANATION

OUTCROP OF THE MADISON LIME-

 STONE (from Strobel and others,

 1999)

MADISON LIMESTONE ABSENT

 (from Carter and Redden, 1999d)

STIFF DIAGRAM--

WELL COMPLETED IN THE 

 MADISON AQUIFER

Sodium + Potassium

Calcium

Magnesium

Chloride + Fluoride

Bicarbonate + Carbonate

Sulfate

10 10 0

CONCENTRATION, IN MILLIEQUIVALENTS PER LITER

LIMESTONE HEADWATER SPRING

104o 45' 103o

30'

15' 103o

30'

44o

45'

15'

44o

45'

30'

43o

15'

ARTESIAN SPRING

Base modified from U.S. Geological Survey digital data,

1:100,000, 1977, 1979, 1981, 1983, 1985

Rapid City, Office of City Engineer map, 1:18,000, 1996

Universal Transverse Mercator projection, zone 13
Ground-Water Characteristics 55

Figure 35. Stiff diagrams (Stiff, 1951) showing the distribution of common-ion chemistry in the Minnelusa aquifer. 

Approximation location of anhydrite dissolution front showing transition between low and high sulfate concentrations 

also is shown (from Naus and others, 2001).

N. Fork Rapid Cr

Belle Fourche

Reservoir

FOURCHE

Victoria

Spring

Rhoads Fork

Coolidge

Highland

Angostura

Reservoir

Castl e Cr

N. Fork Castle Cr

Hell

Canyon

Canyon

Red

Bear

Gulch

Creek

Crow

Sheridan

Lake

Hot Brook Canyon

Cox

Lake

Deerfield

Reservoir

Pactola

Reservoir

Indian Cr

Horse

Creek

Owl

BELLE

Creek

RIVER

REDWATER

R I VER

Creek

Cr

Little Spearfish

Spearfish

Creek

Spearfish

Whitewood

Creek

Creek

Bear

Butte

Elk

Elk

Creek

Creek

Creek

Boxelder

Rapid

Rapid

Creek

Creek

Creek

Spring

Creek

French

Creek

Creek

Creek

Grace

Creek

Creek

Creek

S. Fork

Gillette

S. Fork Rapid Cr

Battle

French

Beaver

Beaver

Creek

Creek

Creek

Creek

Creek

Fall R

Hat

Creek

Creek

Horsehead

CHEYENNE

RIVER

Cottonwood

Hay Creek

Bottom

False

Creek

Spokane

Lame

Johnny

Higgins

Beaver

Cr

Whitetail

Cr

Cr

Cr Cr

Gulch

Annie

Squaw

Deadwood

Creek

Alkali

Iron Cr

Elk

Little

Creek

Castle

Castle

Creek

Creek

Bear Gulch

Cr Strawberry

Boles

Canyon

Canyon

Redbird Canyon

Cold

Beaver

Spring

C s

reek

Creek

Whitewood

Spearfish

Saint

Onge

DEADWOOD

Lead

BELLE FOURCHE

Newell

STURGIS

Blackhawk

Piedmont

Tilford

Box Elder 

Hill City

Hermosa

CUSTER

HOT SPRINGS

Edgemont

Minnekahta

Tinton Central

City

Roubaix

Nemo

Vale

Nisland

Hayward

Keystone

Rochford

Pringle

Fairburn

Buffalo Gap

Dewey

Cascade

Springs

Igloo

Provo

Oral

Rockerville

RAPID CITY

LIMESTONE PLATEAU

 Wind Cave

National Park

Jewel Cave

National

Monument

Mt. Rushmore

National

Memorial

CUSTER

STATE

PARK

Wind

Cave

Harney

Peak

x

Ellsworth

Air Force

Base

BUTTE CO

LAWRENCE CO MEADE CO

PENNINGTON CO

CUSTER CO

FALL RIVER CO

WYOMING

SOUTH DAKOTA

0 10 20

0 10 20 MILES

KILOMETERS

Less than 250

ESTIMATED SULFATE CONCEN-

 TRATIONS IN MINNELUSA

 AQUIFER, IN MILLIGRAMS PER

 LITER

250 to 1,000 

Greater than 1,000

EXPLANATION

OUTCROP OF MINNELUSA

 FORMATION (from Strobel and

 others, 1999)

MINNELUSA FORMATION ABSENT

 (from Carter and Redden, 1999c)

STIFF DIAGRAM--

WELL COMPLETED IN THE 

 MINNELUSA AQUIFER

Sodium + Potassium

Calcium

Magnesium

Chloride + Fluoride

Bicarbonate + Carbonate

Sulfate

10 10 0

CONCENTRATION, IN MILLIEQUIVALENTS PER LITER

104o 45' 103o

30'

15' 103o

30'

44o

45'

15'

44o

45'

30'

43o

15'

LIMESTONE HEADWATER SPRING

ARTESIAN SPRING

Base modified from U.S. Geological Survey digital data,

1:100,000, 1977, 1979, 1981, 1983, 1985

Rapid City, Office of City Engineer map, 1:18,000, 1996

Universal Transverse Mercator projection, zone 13
56 Hydrology of the Black Hills Area, South Dakota

Sulfate concentrations in the Minnelusa aquifer 

are dependent on the amount of anhydrite present in the 

Minnelusa Formation. Near the outcrop, sulfate concentrations generally are low (less than 250 mg/L) 

because anhydrite has been removed by dissolution. An 

abrupt increase in sulfate concentrations occurs downgradient, where a transition zone surrounds the core of 

the Black Hills. This transition zone is the area within 

which the sulfate concentrations range from 250 to 

1,000 mg/L (fig. 35) and marks an area of active 

removal of anhydrite by dissolution. Downgradient 

from the transition zone, sulfate concentrations are 

greater than 1,000 mg/L, which delineates a zone in 

which thick anhydrite beds remain in the formation. 

The transition zone probably is shifting downgradient 

over geologic time as the anhydrite in the formation is 

dissolved (Kyllonen and Peter, 1987).

Figures 34 and 35 also show Stiff diagrams 

(Stiff, 1951) for artesian springs in the Black Hills area, 

most of which probably originate from the Madison 

and/or Minnelusa aquifers (Naus and others, 2001). 

Artesian springs with high sulfate concentrations probably are influenced by anhydrite in the Minnelusa 

Formation. Artesian springs with low sulfate concentrations occur only upgradient from the transition zone 

(fig. 35). Additional discussions regarding potential 

sources of artesian springs are presented in subsequent 

sections of the report. 

Concentrations and variability of many trace 

elements are small in the major aquifers. Strontium 

generally has higher concentrations than other trace 

elements, but is not harmful. Similarly, barium, boron, 

iron, manganese, lithium, and zinc concentrations also 

may be high in comparison to other trace elements.

Most naturally occurring radionuclides in water 

are the result of radioactive decay of uranium-238, 

thorium-232, and uranium-235, with uranium-238 producing the greatest part of the radioactivity observed 

(Hem, 1985). In general, gross alpha-particle activity, 

gross-beta activity, and radium-226 concentrations, are 

higher in the Deadwood and Inyan Kara aquifers than 

in the Madison, Minnelusa, and Minnekahta aquifers. 

In the Deadwood aquifer, more than 30 percent 

of the samples analyzed for radium-226 or radium-226 

and radium-228 exceeded the MCL of 5 pCi/L for the 

combined radium-226 and radium-228 standard. 

Almost 90 percent of the samples from the Deadwood 

aquifer exceeded the proposed MCL of 300 pCi/L for 

radon in States without an active indoor air program; 

several of these samples (fig. 36) also exceeded the 

proposed MCL of 4,000 pCi/L for radon in States with 

an active indoor air program. Samples from the Deadwood aquifer have lower uranium concentrations relative to the other major aquifers, which may be due to 

the reducing conditions of the Deadwood aquifer 

(Rounds, 1991).

Uranium deposits have been mined in the Inyan 

Kara Group in the southern Black Hills. Uranium may 

be introduced into the Inyan Kara Group through 

upward leakage of water from the Minnelusa aquifer 

(Gott and others, 1974). As water in the Inyan Kara 

aquifer migrates downgradient, geochemical conditions favor the precipitation of uranium (Gott and 

others, 1974). Some water from the Inyan Kara aquifer, 

especially in the southern Black Hills, contains relatively high concentrations of radionuclides. Almost 

20 percent of the samples collected from the Inyan 

Kara aquifer exceeded the MCL for the combined 

radium-226 and radium-228 standard; all but one of 

these samples exceeding the MCL were from wells in 

the southern Black Hills. About 4 percent of the 

samples exceeded the MCL for uranium; all these 

samples exceeding the MCL were from wells located in 

the southern Black Hills.

General Characteristics for Minor Aquifers

Water-quality characteristics were summarized 

by Williamson and Carter (2001) for various minor 

aquifers. The minor aquifers in the study area include 

the Newcastle aquifer and alluvial aquifers. Local aquifers do exist in the various semiconfining and confining 

units. Water-quality data also were summarized for 

several of these local aquifers, which included the 

Spearfish, Sundance, Morrison, Graneros, and Pierre 

aquifers.

Relations between dissolved solids and specific 

conductance concentrations are presented in figure 37 

for the minor aquifers with sufficient data, which 

include the Sundance, Morrison, Newcastle, and 

alluvial aquifers. The r2 values are consistently high, 

indicating strong correlations for these aquifers.

Water in many of the minor aquifers can be very 

hard and high in dissolved solids concentrations. Most 

samples from the Sundance aquifer indicate slightly 

saline water. Sulfate concentrations also can be high in 

the minor aquifers, such as the Spearfish aquifer where 

high sulfate concentrations can result from dissolution 

of gypsum. Both dissolved solids and sulfate concentrations are low in the Newcastle aquifer. A variety of 

water types can occur within and among the minor
Ground-Water Characteristics 57

Figure 36. Distribution of radon concentrations in the Deadwood aquifer (from Williamson and Carter, 2001).

BUTTE CO

LAWRENCE CO MEADE CO

PENNINGTON CO

CUSTER CO

FALL RIVER CO

WYOMING

SOUTH DAKOTA

N. Fork Rapid Cr

Belle Fourche

Reservoir

FOURCHE

Victoria

Spring

Rhoads Fork

Coolidge

Highland

Angostura

Reservoir

Castl e Cr

N. Fork Castle Cr

Hell

Canyon

Canyon

Red

Bear

Gulch

Creek

Crow

Sheridan

Lake

Hot Brook Canyon

Cox

Lake

Deerfield

Reservoir

Pactola

Reservoir

Indian Cr

Horse

Creek

Owl

BELLE

Creek

RIVER

REDWATER

R I VER

Creek

Cr

Little Spearfish

Spearfish

Creek

Spearfish

Whitewood

Creek

Creek

Bear

Butte

Elk

Elk

Creek

Creek

Creek

Boxelder

Rapid

Rapid

Creek

Creek

Creek

Spring

Creek

French

Creek

Creek

Creek

Grace

Creek

Creek

Creek

S. Fork

Gillette

S. Fork Rapid Cr

Battle

French

Beaver

Beaver

Creek

Creek

Creek

Creek

Creek

Fall R

Hat

Creek

Creek

Horsehead

CHEYENNE

RIVER

Cottonwood

Hay Creek

Bottom

False

Creek

Spokane

Lame

Johnny

Higgins

Beaver

Cr

Whitetail

Cr

Cr

Cr Cr

Gulch

Annie

Squaw

Deadwood

Creek

Alkali

Iron Cr

Elk

Little

Creek

Castle

Castle

Creek

Creek

Bear Gulch

Cr Strawberry

Boles

Canyon

Canyon

Redbird Canyon

Cold

Beaver

Spring

C s

reek

Creek

Whitewood

Spearfish

Saint

Onge

DEADWOOD

Lead

BELLE FOURCHE

Newell

STURGIS

Blackhawk

Piedmont

Tilford

Box Elder 

Hill City

Hermosa

CUSTER

HOT SPRINGS

Edgemont

Minnekahta

Tinton Central

City

Roubaix

Nemo

Vale

Nisland

Hayward

Keystone

Rochford

Pringle

Fairburn

Buffalo Gap

Dewey

Cascade

Springs

Igloo

Provo

Oral

Rockerville

RAPID CITY

LIMESTONE PLATEAU

 Wind Cave

National Park

Jewel Cave

National

Monument

Mt. Rushmore

National

Memorial

CUSTER

STATE

PARK

Wind

Cave

Harney

Peak

x

Ellsworth

Air Force

Base

5,800

6,600

5,300

2,700

1,400 1,100

1,500

900

560

920 800

1,600

220

80

1,300

690

5,800

6,600

5,300

2,700

1,400 1,100

1,500

900

560

920 800

1,600

220

80

1,300

690

0 10 20

0 10 20 MILES

KILOMETERS

OUTCROP OF DEADWOOD

 FORMATION (from Strobel

 and others, 1999)

DEADWOOD FORMATION

 ABSENT (from Carter and

 Redden, 1999e)

RADON CONCENTRATION--

 Number is radon concentration

 in picocuries per liter. Circle

 size increases with increasing

 concentrations 

Less than 300

300 to 3,000

Greater than 3,000

104 EXPLANATION o 45' 103o

30'

15' 103o

30'

44o

45'

15'

44o

45'

30'

43o

15'

Base modified from U.S. Geological Survey digital data,

1:100,000, 1977, 1979, 1981, 1983, 1985

Rapid City, Office of City Engineer map, 1:18,000, 1996

Universal Transverse Mercator projection, zone 13

80

500

5,300
58 Hydrology of the Black Hills Area, South Dakota

aquifers. In general, the dominance of sodium and sulfate increases with increasing amounts of shale present 

in the formations due to the large cation-exchange 

capabilities of clay minerals (generally sodium concentrations increase) and due to the reduced circulation of 

water through the shale (Hem, 1985). The dominance 

of calcium, magnesium, and bicarbonate increases with 

increasing amounts of sandstone (where calcium carbonate commonly is the cementing material) and 

carbonate rocks present in the geologic units. The 

Sundance aquifer has the highest selenium concentrations of all aquifers considered in this report. 

Concentrations of common ions in alluvial 

aquifers generally increase with increasing distance 

from the core of the Black Hills, which is largely due to 

contact of the water with underlying geologic units and 

to the composition of alluvial deposits. Wells completed in alluvial deposits that do not overlie Cretaceous shales generally yield fresh water of a calcium 

bicarbonate or calcium magnesium bicarbonate type. 

Wells that are completed in alluvial deposits that 

overlie the Cretaceous shales generally yield slightly 

saline water in which sodium and/or sulfate is dominant. Water from alluvial aquifers may be high in uranium concentrations, especially in the southern Black 

Hills. About 17 percent of the samples exceeded the 

proposed MCL for uranium, and all samples exceeding 

this MCL were from wells in the southern Black Hills. 

Figure 37. Relations between dissolved solids and specific conductance for the minor aquifers.

Sundance aquifer

DISSOLVED SOLIDS (S), IN MILLIGRAMS PER LITER

SPECIFIC CONDUCTANCE (K),

IN MICROSIEMENS PER CENTIMETER

SPECIFIC CONDUCTANCE (K),

IN MICROSIEMENS PER CENTIMETER

Newcastle aquifer

Morrison aquifer

Alluvial aquifers

0 4,000 1,000 2,000 3,000

0

2,000

500

1,000

1,500

S = 0.7986K - 129.34

r

2 = 0.98

N = 10

0 1,500 500 1,000

0

1,000

200

400

600

800

S = 0.7601K - 66.71

r

2 = 0.98

N = 7

0 2,000 500 1,000 1,500

0

1,000

200

400

600

800

S = 0.7105K - 67.20

r

2 = 0.98

N = 8

0 4,000 1,000 2,000 3,000

0

2,500

500

1,000

1,500

2,000

S = 0.8302K - 105.62

r

2 = 0.96

N = 64
Ground-Water Characteristics 59

Susceptibility to Contamination

The Black Hills Hydrology Study focused primarily on determination of natural water-quality characteristics, and investigation of contamination 

potential was not an objective of the study. The susceptibility of the aquifers to contamination in the study 

area is an important issue, however, and can be 

addressed to some extent.

Nitrite plus nitrate concentrations for various 

aquifers (fig. 38) can provide a general indication of 

possible human influence. Although nitrogen is essential for plant growth, high concentrations of nitrite plus 

nitrate can cause excessive plant growth and can be 

harmful to livestock and humans. Excessive concentrations of nitrite plus nitrate in drinking water are a health 

concern for pregnant women, children, and the elderly 

(may cause methemoglobinemia (blue-baby syndrome) in small children). Nitrite plus nitrate in ground 

water can originate from natural processes or as contamination from nitrogen sources, such as fertilizers 

and sewage, on the land surface or in the soil zone. 

Nitrite plus nitrate concentrations for most samples in 

the Black Hills area generally are low (fig. 38); however, samples approaching or exceeding the national 

nitrate background concentration of 2.0 mg/L (U.S. 

Geological Survey, 1999) may provide indications of 

possible human influence in a variety of land-use settings. The extreme values for nitrite plus nitrate in 

figure 38 are unusually high and may reflect poor well 

construction and surface contamination as opposed to 

aquifer conditions.

The potential for contamination of ground water 

in the Black Hills area can be large because many 

aquifer outcrops can be subject to various forms of land 

development. Rapid ground-water velocities also are 

possible in many aquifers because of high secondary 

permeability. Contamination of ground water by septic 

tanks has been documented for wells in the Blackhawk, 

Piedmont, and Sturgis areas (Bartlett and West 

Engineers, Inc., 1998).

Figure 38. Boxplots of concentrations of nitrite plus nitrate for selected aquifers (modified from Williamson and 

Carter, 2001).

EXPLANATION

Highest reporting limit

Maximum Contaminant Level

 (U.S. Environmental Protection

 Agency, 1994a)

Number of samples/Number of

 samples with concentrations

 below the laboratory reporting

 limit

114/15

25th percentile

Median

75th percentile

Data value less than or equal to

 1.5 times the interquartile range

 outside the quartile

Outlier data value less than or

 equal to 3 and more than 1.5

 times the interquartile range

 outside the quartile

Outlier data value more than 3

 times the interquartile range

 outside the quartile

0

20

5

10

15

65

60

NITRITE PLUS NITRATE, IN MILLIGRAMS PER LITER

40/8 8/4 74/14 157/29 23/4 81/29 9/0 6/4 70/9

AQUIFER

Precambrian

Deadwood

Madison

Minnelusa

Minnekahta

Inyan Kara

Sundance Alluvial

Newcastle
60 Hydrology of the Black Hills Area, South Dakota

Maps showing sensitivity of ground water to 

contamination were produced by Putnam (2000) for 

Lawrence County and by Davis and others (1994) for 

the Rapid Creek Basin. The most sensitive hydrogeologic units are limestones, unconsolidated sands and 

gravels, and sandstones (Putnam, 2000). The least sensitive units include shales or units with interbedded 

shales. The Madison, Minnelusa, and Minnekahta 

aquifers are especially sensitive to contamination 

because of high secondary permeability and potential 

for streamflow recharge. 

Summary Relative to Water Use

Concentrations of various constituents 

exceeding SMCL’s and MCL’s affect the use of water 

in some areas for many aquifers within the study area. 

Most concentrations exceeding standards are for various SMCL’s and generally affect the water only aesthetically. Radionuclide concentrations can be high in 

some of the major aquifers, especially in the Deadwood 

and Inyan Kara aquifers, and may preclude the use of 

water in some areas. Hard water may require special 

treatment for certain uses. Other factors, such as the 

sodium adsorption ratio (SAR) and specific conductance, affect irrigation use. 

The general suitability of ground water for irrigation in the study area can be determined by using the 

South Dakota irrigation-water diagram (fig. 39). The 

diagram is based on South Dakota irrigation-water 

standards (revised January 7, 1982) and shows the 

State’s water-quality and soil-texture requirements for 

the issuance of an irrigation permit. The adjusted SAR 

for each aquifer was calculated according to Koch 

(1983) from the mean concentrations of calcium, magnesium, sodium, and bicarbonate for each aquifer. 

Water from all aquifers, with the exceptions of the 

Pierre and Sundance aquifers, generally is suitable for 

irrigation, but may not be in specific instances if either 

the specific conductance or the SAR is high.

High concentrations of iron and manganese 

occasionally can hamper the use of water from the 

Precambrian aquifer. None of the reported samples 

from the Precambrian aquifer exceeded drinking-water 

standards for radionuclides. 

The principal deterrents to use of water from the 

Deadwood aquifer are high concentrations of radionuclides, including radium-226 and radon. In addition, 

concentrations of iron and manganese can be high.

Water from the Madison aquifer can contain high 

concentrations of iron and manganese that may deter its 

use. Water from the Madison aquifer is hard to very 

hard and may require special treatment for certain uses. 

In downgradient wells (generally deeper than 2,000 ft), 

concentrations of dissolved solids and sulfate also may 

deter use from this aquifer. Hot water from deep wells 

and in the Hot Springs area, may not be desirable for 

some uses. Radionuclide concentrations in the 

Madison aquifer generally are acceptable.

The principal properties or constituents that may 

hamper the use of water from the Minnelusa aquifer 

include hardness and high concentrations of iron and 

manganese. Generally, downgradient wells (generally 

deeper than 1,000 ft) also have high concentrations of 

dissolved solids and sulfate. Hot water, from deep 

wells, may not be desirable for some uses. Arsenic concentrations in the Minnelusa aquifer exceed the revised 

MCL of 10 μg/L in some locations. Only a few samples 

exceeded the MCL’s for various radionuclides.

Samples from the Minnekahta aquifer are available only from shallow wells near the outcrop. Water 

from the Minnekahta aquifer is harder than that from 

any of the other major aquifers in the study area, and 

may require special treatment for certain uses. Water 

generally is suitable for all water uses; few samples 

exceeded SMCL’s and no samples available for this 

study from the Minnekahta aquifer exceeded drinkingwater standards for any radionuclides.

The use of water from the Inyan Kara aquifer 

may be hampered by high concentrations of dissolved 

solids, iron, sulfate, and manganese. In the southern 

Black Hills, radium-226 and uranium concentrations 

also may preclude its use. Hard water from wells 

located on or near the outcrop of the Inyan Kara Group 

may require special treatment. 

The use of water from the minor aquifers 

(Spearfish, Sundance, Morrison, Pierre, Graneros, 

Newcastle, and alluvial aquifers) may be hampered by 

hardness and concentrations of dissolved solids and 

sulfate. Concentrations of radionuclides, with the 

exception of uranium, generally are at acceptable levels 

in samples from the minor aquifers. Selenium concentrations in some places are an additional deterrent to the 

use of water from the Sundance aquifer.

Water from alluvial aquifers generally is very 

hard and may require special treatment for certain uses. 

High concentrations of dissolved solids, sulfate, iron, 

and manganese may limit the use of water from alluvial 

aquifers that overlie the Cretaceous shales. In the 

southern Black Hills, uranium concentrations in 

alluvial aquifers can be high in many locations.
Ground-Water Characteristics 61

Figure 39. South Dakota irrigation-water classification diagram for selected aquifers (from Williamson and Carter, 

2001). This diagram is based on South Dakota standards (revised Jan. 7, 1982) for maximum allowable specific 

conductance and adjusted sodium-adsorption-ratio values for which an irrigation permit can be issued for applying 

water under various soil-texture conditions. Water can be applied under all conditions at or above the plotted point, 

but not below it, provided other conditions as defined by the State Conservation Commission are met (from Koch, 

1983).

A1 A2 A1 A2 A1 A2

B1

C1

B2 B1

C1 B2

D2 E1

D3 E2 E1 B3

C2

D1

B3

B1

B2

C2 C1

C3 D1

D2

E3 E2 C2

C3

D3

E3 C3

B3

0 3 6 7 8 9 10 11 12

3,100

3,000

2,900

2,800

2,700

2,600

2,500

2,400

2,300

2,200

2,100

2,000

1,900

1,800

1,700

1,600

1,500

1,400

1,300

1,200

1,100

1,000

ADJUSTED SODIUM-ADSORPTION RATIO (SAR)

MULTIPLIED BY 0.7

SPECIFIC CONDUCTANCE, IN MICROSIEMENS PER CENTIMETER AT 25o CELSIUS 

(ECx106 AT 25o C) ADJUSTED FOR CALCIUM, SULFATE, AND RAINFALL

EXPLANATION

SOIL TEXTURE

 Sand

 Loamy sands, sandy loams

 Loams, silts, silt loams

 Sandy clay loams, silty clay

 loams, clay loams

 Silty clays, sandy clays, clays

DEPTH BELOW LAND SURFACE

 TO A MORE-PERMEABLE OR

 LESS-PERMEABLE MATERIAL

 40 inches or less to a more-

 permeable material

 40 to 72 inches to a more-

 permeable material

 20 to 60 inches to a less-

 permeable material

SPECIFIC CONDUCTANCE

 Maximum values are based on

 12 inches or less average

 rainfall during the frost-free

 season. For each additonal 

 inch of rainfall, the maximum

 values of conductance may be 

 increased by 100 microsiemens

 per centimeter at 25oC. Average

 growing season rainfall for the

 Black Hills area is 14 inches, so

 the conductance of each plotted

 value has been reduced by 200

 microsiemens per centimeter at

 25oC.

 For water having more than

 200 milligrams per liter of

 calcium and more than 960

 milligrams per liter of sulfate,

 the maximum conductance

 value may be increased by 400

 microsiemens per centimeter at

 25oC.

A

B

C

E

1

2

3

AVERAGE CHEMICAL QUALITY OF

 MAJOR AQUIFERS

AVERAGE CHEMICAL QUALITY OF

 MINOR AQUIFERS

D

Inyan Kara

Minnekahta

Minnelusa

Madison

Deadwood

Precambrian

Alluvial

Graneros

Newcastle

Pierre

Morrison

Sundance

Spearfish

900

800

700

600

500

400

300

200

100

x

x

*

x

*

#

#

x

*

*

#

#
62 Hydrology of the Black Hills Area, South Dakota

Surface-Water Characteristics

Within this section, surface-water characteristics, including both streamflow and water-quality characteristics, are described. Surface-water characteristics 

can be affected by numerous physical variables such as 

topography, land cover, soil conditions, mineralogy, 

and ground-water conditions, all of which may be 

affected by geologic conditions. In addition, streamflow is affected by numerous climatic variables 

including timing, intensity, and amount of precipitation, as well as other variables affecting evaporative 

processes.

Streamflow Characteristics

Streamflow characteristics in the Black Hills 

area are highly affected by the hydrogeologic settings 

previously described (fig. 23). Streamflow characteristics described in this section include variability of 

streamflow, the response of streamflow to precipitation, and annual yield characteristics. More detailed 

discussions of these topics were presented by Driscoll 

and Carter (2001).

Streamflow Variability

A distinctive effect of hydrogeologic setting is 

on the timing and variability of streamflow, which 

results primarily from interactions between surface 

water and ground water. Locations of streamflowgaging stations for basins representative of the five 

hydrogeologic settings were presented in figure 23. 

Site information and selected flow characteristics are 

summarized (by hydrogeologic setting) in table 5. One 

of the flow characteristics summarized is the “base 

flow index” (BFI), which represents the estimated percentage of average streamflow contributed by base 

flow, for any given gage. BFI’s were determined with a 

computer program described by Wahl and Wahl (1995).

Table 5 also includes mean flow values for representative gages (for the periods of record shown) in 

cubic feet per second and mean values of annual basin 

yield, expressed in inches per unit area. Because basin 

yields are normalized, relative to surface drainage area, 

values are directly comparable among different gages. 

For example, the mean flow of 11.73 ft3

/s for Castle 

Creek (station 06409000) is about 2.7 times larger than 

the mean flow of 4.33 ft3

/s for Cold Springs Creek 

(station 06429500); however, the mean annual basin 

yield for Castle Creek (2.01 inches) is smaller than for 

Cold Springs Creek (3.10 inches).

The last flow characteristic summarized in 

table 5 is the coefficient of variation (standard deviation divided by mean) for annual basin yield, which 

provides a useful measure of annual flow variability. 

This statistic is directly comparable among different 

gages because the standard deviations are normalized 

relative to means. For example, standard deviations for 

Beaver Creek at Mallo Camp (06392900) and Rhoads 

Fork (06408700) are very different; however, coefficients of variation are nearly identical. A notable 

example is provided by two gages representative of 

artesian spring basins—Cascade Springs (06400497) 

and Cox Lake (06430540), which have anomalously 

large values for annual basin yield (orders of magnitude higher than annual precipitation) because of 

extremely large artesian springflow that occurs in very 

small drainages. Standard deviations for these sites are 

the largest in table 5; however, the coefficients of 

variation are the smallest, which is consistent with the 

BFI’s, which are the largest in the table and are indicative of extremely large contributions from base flow.

Duration curves showing variability in daily 

flow are presented in figure 40 for selected basins. 

Streamflow variability is small for limestone headwater and artesian spring basins because streamflow 

consists almost entirely of base flow from spring discharge. For the individual limestone headwater basins, 

measured daily flows generally vary by less than an 

order of magnitude, indicating that direct runoff is very 

uncommon from outcrops of the Madison Limestone 

and Minnelusa Formation, which are the predominant 

outcrops for this setting. Streams in the crystalline core 

setting have large variability in daily flow. Loss zone 

and exterior settings have large flow variability and 

low-flow and zero-flow periods are common.

Relative variability of monthly and annual flow 

also is much smaller for basins representative of limestone headwater and artesian spring settings than for 

the other settings (figs. 41 and 42). Annual flow values 

are expressed as annual yield (fig. 42) for all hydrogeologic settings except the artesian spring setting, for 

which annual yield values can be unrealistically large 

(table 5), as previously discussed. Coefficients of variation for these settings are consistently smaller than for 

the other settings (table 5). BFI’s are consistently 

larger, indicating large proportions of base flow for 

these settings. All measures considered indicate much 

higher flow variability for the other three settings.
Surface-Water Characteristics 63

Table 5. Summary of selected site information and flow characteristics for streamflow-gaging stations representative of hydrogeologic settings [Modified from Driscoll and Carter (2001). --, not determined]

Station

number Station name

Drainage

area

(square 

miles)

Period of record 

used

(water years)

Base

flow

index

(percent)

Mean flow

(cubic

feet per

second)

Annual basin yield

Mean

(inches)

Standard 

deviation

Coefficient of 

variation

(standard deviation/mean)

Limestone Headwater Basins

06392900 Beaver Creek at Mallo Camp, near Four Corners, 

WY1

10.3 1975-82,

1992-98

88.6 1.88 2.48 0.63 0.25

06408700 Rhoads Fork near Rochford 7.95 1983-98 98.7 5.47 9.34 2.48 .2706409000 Castle Creek above Deerfield Reservoir,

near Hill City

79.2 1949-98 87.1 11.73 2.01 .75 .37

06429500 Cold Springs Creek at Buckhorn, WY1 19.0 1975-82,

1992-98

91.4 4.33 3.10 .68 .22

06430770 Spearfish Creek near Lead 63.5 1989-98 291.0 225.43 25.44 22.59 2.48

06430850 Little Spearfish Creek near Lead 25.8 1989-98 97.0 16.59 8.74 2.31 .26

Crystalline Core Basins

06402430 Beaver Creek near Pringle 45.8 1991-98 73.1 2.86 .85 .76 .8906402995 French Creek above Stockade Lake, near Custer3 68.7 -- -- -- -- -- --

06403300 French Creek above Fairburn 105 1983-98 55.5 10.94 1.42 1.19 .8406404000 Battle Creek near Keystone 58.0 1962-98 45.4 9.39 2.20 1.59 .7206404800 Grace Coolidge Creek near Hayward3 7.48 -- -- -- -- -- --

06404998 Grace Coolidge Creek near Game Lodge, near Custer 25.2 1977-98 58.9 5.07 2.73 2.36 .8606405800 Bear Gulch near Hayward 4.23 1990-98 41.1 1.48 4.75 2.76 .5806406920 Spring Creek above Sheridan Lake, near Keystone3 127 -- -- -- -- -- --06407500 Spring Creek near Keystone 163 1987-98 54.1 25.06 2.09 1.73 .8306422500 Boxelder Creek near Nemo 96.0 1967-98 64.9 19.53 2.76 2.19 .7906424000 Elk Creek near Roubaix 21.5 1992-98 61.1 13.42 8.48 4.08 .4806430800 Annie Creek near Lead 3.55 1989-98 51.1 1.72 6.55 4.42 .6706430898 Squaw Creek near Spearfish 6.95 1989-98 52.5 3.76 7.34 4.44 .6006436156 Whitetail Creek at Lead 6.15 1989-98 63.0 4.79 10.57 6.01 .5706437020 Bear Butte Creek near Deadwood1 16.6 1989-98 58.3 8.35 6.84 4.07 .60
64 Hydrology of the Black Hills Area, South Dakota Loss Zones Basins 06408500 Spring Creek near Hermosa 199 1950-98 44.1 7.15 .49 .73 1.49 06423010 Boxelder Creek near Rapid City 128 1979-98 14.4 5.88 .62 1.23 1.98 Artesian Spring Basins 06392950 Stockade Beaver Creek near Newcastle, WY1 107 1975-82, 1992-98 93.5 12.15 1.54 0.23 0.15 06400497 Cascade Springs near Hot Springs .47 1977-95 99.2 19.53 564 40.34 .07 06402000 Fall River at Hot Springs 137 1939-46,

1948-98

96.0 23.61 2.34 .25 .11

06402470 Beaver Creek above Buffalo Gap 111 1991-97 97.4 10.21 1.25 .25 .2006412810 Cleghorn Springs at Rapid City3 -- -- -- -- -- -- --

06429905 Sand Creek near Ranch A, near Beulah, WY1 267 1977-83,

1992-98

95.1 22.58 1.15 .22 .19

06430532 Crow Creek near Beulah, WY 40.8 1993-98 92.6 40.68 13.5 1.13 .0806430540 Cox Lake outlet near Beulah, WY .07 1991-95 99.3 4.22 819 9.16 .01

Exterior Basins

06395000 Cheyenne River at Edgemont3 7,143 -- -- -- -- -- --

06400000 Hat Creek near Edgemont 1,044 1951-98 15.5 16.61 .22 .26 1.1806400875 Horsehead Creek at Oelrichs1 187 1984-98 12.6 6.75 .49 .70 1.43

06433500 Hay Creek at Belle Fourche 121 1954-96 17.5 1.74 .20 .23 1.1506436700 Indian Creek near Arpan1 315 1962-81 6.6 19.98 .86 .92 1.0706436760 Horse Creek above Vale3 464 -- -- -- -- -- --06437500 Bear Butte Creek near Sturgis1 192 1946-72 32.3 13.93 .99 1.04 1.05

1Site used only for analysis of streamflow characteristics.2Flow characteristics affected by relatively consistent diversions of about 10 cubic feet per second.3Site used only for analysis of water-quality characteristics.

Table 5. Summary of selected site information and flow characteristics for streamflow-gaging stations representative of hydrogeologic settings–Continued[Modified from Driscoll and Carter (2001). --, not determined]

Station

number Station name

Drainage

area

(square 

miles)

Period of record 

used

(water years)

Base

flow

index

(percent)

Mean flow

(cubic

feet per

second)

Annual basin yield

Mean

(inches)

Standard 

deviation

Coefficient of 

variation

(standard deviation/mean)
Surface-Water Characteristics 65

Figure 40. Duration curves of daily mean streamflow for basins representative of hydrogeologic settings (from 

Driscoll and Carter, 2001).

0.01

10,000

0.02

0.05

0.1

0.2

0.5

1

2

5

10

20

50

100

1,000

500

200

2,000

5,000

Stockade Beaver Creek (06392950)

Cascade Springs (06400497)

Fall River (06402000)

Beaver Creek (06402470)

Sand Creek (06429905)

Crow Creek (06430532)

Cox Lake (06430540)

Artesian spring basins

0.1 1 2 5 10 20 30 40 50 60 70 80 90 95 98 99 99.9

PERCENT OF TIME INDICATED VALUE

WAS EQUALED OR EXCEEDED

0.01

10,000

0.02

0.05

0.1

0.2

0.5

1

2

5

10

20

50

100

1,000

500

200

2,000

5,000

0.01

10,000

0.02

0.05

0.1

0.2

0.5

1

2

5

10

20

50

100

1,000

500

200

2,000

5,000

0.01

10,000

0.02

0.05

0.1

0.2

0.5

1

2

5

10

20

50

100

1,000

500

200

2,000

5,000

0.01

10,000

0.02

0.05

0.1

0.2

0.5

1

2

5

10

20

50

100

1,000

500

200

2,000

5,000

0.01

10,000

0.02

0.05

0.1

0.2

0.5

1

2

5

10

20

50

100

1,000

500

200

2,000

5,000

DAILY MEAN STREAMFLOW, IN CUBIC FEET PER SECOND

Rhoads Fork (06408700)

Little Spearfish Creek (06430850)

Castle Creek (06409000)

Spearfish Creek (06430770)

Beaver Creek (06392900)

Cold Springs Creek (06429500)

Limestone headwater basins

Beaver Creek (06402430)

French Creek (06403300)

Battle Creek (06404000)

Grace Coolidge (06404998)

Bear Gulch (06405800)

Spring Creek (06407500)

Crystalline core basins

Crystalline core basins--Continued

Boxelder Creek (06422500)

Elk Creek (06424000)

Annie Creek (06430800)

Squaw Creek (06430898)

Whitetail Creek (06436156)

Bear Butte Creek (06437020)

0.1 1 2 5 10 20 30 40 50 60 70 80 90 95 98 99 99.9

0.1 1 2 5 10 20 30 40 50 60 70 80 90 95 98 99 99.9 0.1 1 2 5 10 20 30 40 50 60 70 80 90 95 98 99 99.9

0.1 1 2 5 10 20 30 40 50 60 70 80 90 95 98 99 99.9 0.1 1 2 5 10 20 30 40 50 60 70 80 90 95 98 99 99.9

PERCENT OF TIME INDICATED VALUE

WAS EQUALED OR EXCEEDED

Spring Creek (06408500)

Boxelder Creek (06423010)

Loss zone basins

Hat Creek (06400000)

Horsehead Creek (06400875)

Hay Creek (06433500)

Indian Creek (06436700)

Bear Butte Creek (06437500)

Exterior basins
66 Hydrology of the Black Hills Area, South Dakota

Figure 41. Mean monthly streamflow for basins representative of hydrogeologic settings (from Driscoll

and Carter, 2001).

Beaver Creek (06402430)

French Creek (06403300)

Battle Creek (06404000)

Grace Coolidge Creek (06404998)

Bear Gulch (06405800)

Spring Creek (06407500)

Boxelder Creek (06422500)

Spring Creek (06408500)

Boxelder Creek (06423010)

Elk Creek (06424000)

Annie Creek (06430800)

Squaw Creek (06430898)

Whitetail Creek (06436156)

Bear Butte Creek (06437020)

1

100

2

5

10

20

50

Rhoads Fork (06408700)

Castle Creek (06409000)

Cold Springs Creek (06429500)

Spearfish Creek (06430770)

Little Spearfish Creek (06430850)

Limestone headwater basins

Oct Nov Dec Jan Feb Mar Apr May Jun Jul Aug Sep

MONTH

0.01

100

0.02

0.05

0.1

0.2

0.5

1

2

5

10

20

50

MEAN MONTHLY STREAMFLOW, IN CUBIC FEET PER SECOND

Crystalline core basins

0.1

100

0.2

0.5

1

2

5

10

20

50

Loss zone basins

Beaver Creek (06392900)
Surface-Water Characteristics 67

Figure 41. Mean monthly streamflow for basins representative of hydrogeologic settings (from Driscoll 

and Carter, 2001).—Continued

1

100

2

5

10

20

50

Artesian spring basins

Oct Nov Dec Jan Feb Mar Apr May Jun Jul Aug Sep

MONTH

MEAN MONTHLY STREAMFLOW, IN CUBIC FEET PER SECOND

Exterior basins

Beaver Creek (06402470)

Stockade Beaver Creek (06392950)

Cascade Springs (06400497)

Fall River (06402000)

Sand Creek (06429905)

Crow Creek (06430532)

Cox Lake (06430540)

0.001

100

0.002

0.005

0.01

0.02

0.05

0.1

0.2

0.5

1

2

5

10

20

50

Hat Creek (06400000)

Horsehead Creek (06400875)

Hay Creek (06433500)

Indian Creek (06436700)

Bear Butte Creek (06437500)
68 Hydrology of the Black Hills Area, South Dakota

Figure 42. Distribution of annual yield for basins representative of hydrogeologic settings (from Driscoll and Carter, 

2001).

10th percentile

25th percentile

Median

75th percentile

90th percentile

8 Number of observations

Single value

15 16 50 15 10 10

Beaver Creek at

Mallo Camp, WY

(06392900)

Rhoads Fork

near Rochford

(06408700)

Castle Creek above

Deerfield Reservoir

(06409000)

Cold Springs Creek

at Buckhorn, WY

(06429500)

Spearfish Creek

near Lead

(06430770)

Little Spearfish

Creek near Lead

(06430850)

STREAM

0

16

2

4

6

8

10

12

14

ANNUAL YIELD, IN INCHES ANNUAL YIELD, IN INCHES

8 32 10 16 37 22 9 7 10 12 10 10

Beaver

Creek near

Pringle

(06402430)

French

Creek

above

Fairburn

(06403300)

Battle

Creek near

Keystone

(06404000)

Grace

Coolidge

Creek near

Game

Lodge

(06404998)

Bear Gulch

near

Hayward

(06405800)

Spring

Creek

near

Keystone

(06407500)

Boxelder

Creek

near Nemo

(06422500)

Elk

Creek

near

Roubaix

(06424000)

Annie

Creek

near Lead

(06430800)

Squaw

Creek

near

Spearfish

(06430898)

Whitetail

Creek

at Lead

(06436156)

Bear Butte

Creek

near

Deadwood

(06437020)

0

20

2

4

6

8

10

12

14

16

18

Minimum

Maximum

10th percentile

25th percentile

Median

75th percentile

90th percentile

15 Number of observations

Minimum

Maximum

Limestone headwater basins

Crystalline core basins
Surface-Water Characteristics 69

Figure 42. Distribution of annual yield for basins representative of hydrogeologic settings (from Driscoll and Carter, 

2001).—Continued

NOTE: Y-axis is plotted as flow, rather than yield

10th percentile

25th percentile

Median

75th percentile

90th percentile

20 Number of observations

STREAM

ANNUAL STREAMFLOW, IN CUBIC FEET PER SECOND ANNUAL YIELD, IN INCHES

Minimum

Maximum

10th percentile

25th percentile

Median

75th percentile

90th percentile

Single value

Minimum

Maximum

15 Number of observations

15 19 14 59 7 6 5

Stockade Beaver

Creek near

Newcastle, WY

(06392950)

Cascade Springs

near

Hot Springs

(06400497)

Fall River at

Hot Springs

(06402000)

Beaver Creek above

Buffalo Gap

(06402470)

Sand Creek

near Ranch A,

near Beulah, WY

(06429905)

Crow Creek

near Beulah, WY

(06430532)

Cox Lake outlet

near Beulah, WY

(06430540)

0

50

10

20

30

40

49 20 43 48 15 20 27

Spring Creek

near Hermosa

(06408500)

Boxelder

Creek near

Rapid City

(06423010)

Hat Creek

near

Edgemont

(06400000)

Horsehead

Creek at

Oelrichs

(06400875)

Hay Creek at

Belle Fourche

(06433500)

Indian Creek

near Arpan

(06436700)

Bear Butte

Creek near

Sturgis

(06437500)

0

5

1

2

3

4

Loss zone basins

Artesian spring basins

Exterior basins
70 Hydrology of the Black Hills Area, South Dakota

BFI’s for the crystalline core basins generally 

approach or slightly exceed 50 percent (table 5). 

Monthly flow characteristics (fig. 41), however, indicate a short-term response to precipitation patterns 

(fig. 8), which probably indicates a relatively large 

component of interflow contributing to base flow. This 

interpretation is supported by the general physical 

characteristics of the crystalline core basins, where 

large relief and steep planar surfaces provide conditions amenable to non-vertical flow components in the 

unsaturated zone. Ground-water discharge also contributes to streamflow; however, ground-water storage 

available for contribution to streamflow apparently is 

quickly depleted, as evidenced by the lower end of the 

range of annual yield values for the crystalline core 

basins (fig. 42). Daily flow values span two or more 

orders of magnitude for all crystalline core basins 

(fig. 40).

Few gages representative of the loss zone setting 

exist because sustained flow is uncommon downstream 

from outcrop areas where large streamflow losses provide recharge to the Madison and Minnelusa aquifers 

(Hortness and Driscoll, 1998). The only two representative loss zone gages (fig. 23) are located on Spring 

Creek (06408500) and Boxelder Creek (06423010). 

Annual basin yields for these gages are much smaller 

than for gages located upstream (stations 06407500 on 

Spring Creek and 06422500 on Boxelder Creek) and 

relative variability in flow is larger (table 5, 

figs. 40-42). Spring Creek does have relatively consistent base flow (table 5, BFI = 44 percent) from alluvial 

springs that occur a short distance upstream from the 

gage.

Seven representative gages for the artesian 

spring setting are considered (fig. 23), of which two 

(Cascade Springs and Cox Lake) are located in 

extremely small drainages with no influence from 

streamflow losses. Four of the gages are located in 

larger drainages downstream from loss zones, and one 

basin (Fall River, 06402000) heads predominantly 

within the loss zone setting (fig. 23). Monthly means 

(fig. 41) for Fall River show no apparent influence of 

flows through loss zones, in spite of storm flows that 

occasionally increase daily flows (fig. 40). Minor 

influence of flows through loss zones is apparent in 

both monthly and daily flow characteristics for the 

other four gages (figs. 40 and 41). The influence of 

minor irrigation diversions along Stockade Beaver 

Creek (06392950) during late spring and summer 

months also is apparent.

For the exterior setting, daily flows for representative gages vary by more than four orders of magnitude (fig. 40) and zero-flow conditions are common, 

which is consistent with BFI’s that typically are small 

(table 5). Large variability in monthly and annual flows 

also is characteristic for the exterior setting (figs. 41 

and 42). Annual basin yields also are smaller than for 

most other settings, which is consistent with smaller 

precipitation and larger evaporation rates at lower 

altitudes. Many of these sites also are affected by minor 

irrigation withdrawals.

Response to Precipitation

Streams representative of the various hydrogeologic settings generally have distinctive characteristics 

relative to responsiveness to precipitation, as described 

within this section. Methods used for determination of 

precipitation over drainage areas were described by 

Driscoll and Carter (2001), who provided detailed discussions regarding relations between streamflow and 

precipitation.

The limestone headwater basins generally have 

weak correlations between annual streamflow and precipitation, as summarized in table 6. The r2 values are 

low and p-values indicate that the correlations are not 

statistically significant (>0.05) for most of the representative basins, which is consistent with minimal variability in daily (fig. 40) and monthly (fig. 41) flow. 

Correlations with annual streamflow improve when 

“moving-average” precipitation (annual precipitation 

averaged over multiple years) is considered as the 

explanatory variable. Regression information is summarized in table 6 for the number of years of movingaverage precipitation for which r2 values are maximized for each basin.

The regression equation (table 6) for Castle 

Creek (station 06409000) probably is the most reliable, 

in spite of an associated r2 value that is relatively low, 

primarily because the length of record is the longest 

(table 5). High r2

 values for several basins probably 

result primarily from relatively short periods of record; 

thus, associated regression equations for these stations 

may not be representative of long-term conditions. The 

p-values generally indicate strong statistical significance, however, which provides confidence that longterm precipitation patterns are much more important 

than short-term patterns for explaining streamflow 

variability in the limestone headwater setting. This 

concept is consistent with the hydrogeologic setting, 

where streamflow is dominated by headwater springflow.
Surface-Water Characteristics 71

Table 6. Summary of regression information for limestone headwater basins

[Regression information (from Driscoll and Carter, 2001) is provided for streamflow as a function of annual precipitation and as a function of moving average precipitation over a specified number of years. Int, intercept; <, less than]

Station 

number Station name

Annual precipitation Moving average precipitation

r

2 p-value Number

of years r

2 p-value Slope Int

06392900 Beaver Creek at Mallo Camp 0.01 0.668 11 0.24 0.063 0.211 -2.78

06408700 Rhoads Fork .16 .123 9 .93 <.010 .658 -9.12

06409000 Castle Creek .31 <.010 3 .58 <.010 1.043 -10.70

06429500 Cold Springs Creek .01 .800 11 .70 <.010 .722 11.65

06430770 Spearfish Creek near Lead .72 <.010 7 .99 <.010 3.858 -68.63

06430850 Little Spearfish Creek .53 .017 7 .93 <.010 1.450 -19.32

Graphs showing relations between annual 

streamflow and precipitation for crystalline core basins 

are presented in figure 43. Each graph includes a linear 

regression line, along with the corresponding equation 

and r2 value. All of the slopes are highly significant; 

thus, p-values are not shown. The r2 values range from 

0.52 for Beaver Creek (06402430) to 0.87 for Bear 

Gulch (06405800), and are much higher as a group than 

for the limestone headwater basins (table 6), which is 

consistent with larger variability in flow characteristics 

(figs. 40-42).

An exponential regression curve, along with the 

corresponding equation and r2 value, also is shown on 

each graph in figure 43. All of the exponential equations would predict small, positive streamflow for zero 

precipitation (which is not realistic), but avoid prediction of negative streamflow in the lower range of typical annual precipitation, which is indicated for many 

of the linear regression equations.

Each graph in figure 43 also includes a curve 

labeled “runoff efficiency prediction,” which is derived 

from linear regression equations of runoff efficiency as 

a function of precipitation. Runoff efficiency (the ratio 

of annual basin yield to precipitation) represents the 

percentage of annual precipitation returned as streamflow. Runoff efficiency regression lines for the 12 

representative crystalline core basins are shown in 

figure 44; regression equations were presented by 

Driscoll and Carter (2001). Figure 44 indicates that 

within each basin, runoff efficiency increases with 

increasing annual precipitation, and that basins with 

higher precipitation generally have higher efficiencies. 

The runoff efficiency predictions (fig. 43) are 

derived by substituting values for annual precipitation 

into the runoff efficiency regression equations. Runoff 

efficiency predictions are unrealistic (slightly negative) 

for very low precipitation values, but are consistently 

positive for the measured ranges of precipitation and 

also closely resemble the linear regression equations 

(streamflow versus precipitation) through this range.

Relations between streamflow and precipitation 

for the two loss-zone basins are presented in figure 45. 

It is apparent that low-flow and zero-flow years are 

common, with substantial flows occurring only when 

upstream flows are sufficiently large to sustain flow 

through loss zones. A power equation and associated r2

value are shown for each basin, which provide reasonable fits for the nonlinear data.

Regression statistics (annual streamflow versus 

precipitation) for artesian spring basins are summarized in table 7. Regression equations, which are not 

meaningful because of low r2 values and p-values 

greater than 0.05, are not provided. Weak correlations 

are consistent with small variability in flow characteristics (figs. 40-42) associated with ground-water discharge and with long ground-water residence times. 

Naus and others (2001) concluded that large proportions of springflow for several of the representative 

artesian springs have residence times exceeding 

50 years.
72 Hydrology of the Black Hills Area, South Dakota

Figure 43. Relations between annual streamflow and precipitation for crystalline core basins (from Driscoll and Carter, 

2001).

PRECIPITATION, IN INCHES PRECIPITATION, IN INCHES

STREAMFLOW, IN CUBIC FEET PER SECOND

Linear regression

y = 0.346x - 5.51

r2 = 0.52

Exponential regression

y = 0.052e0.142x

r2 = 0.34

Runoff efficiency prediction

Linear regression

y = 0.694x - 9.77

r2 = 0.73

Exponential regression

y = 0.179e0.140x

r2 = 0.73

Runoff efficiency prediction

Linear regression

y = 1.443x - 19.29

r2 = 0.65

Exponential regression

y = 0.5183e0.129x

r2 = 0.53

Runoff efficiency prediction

Grace Coolidge Creek near Game Lodge, near

Custer (06404998)

Linear regression

y = 1.091x - 14.12

r2 = 0.76

Exponential regression

y = 0.3274e0.141x

r2 = 0.72

Runoff efficiency prediction

Battle Creek near Keystone (06404000)

Linear regression

y = 0.168x - 2.779

r2 = 0.87

Exponential regression

y = 0.029e0.147x

r2 = 0.91

Runoff efficiency prediction

Linear regression

y = 3.616x - 53.67

r2 = 0.80

Exponential regression

y = 0.174e0.203x

r2 = 0.62

Runoff efficiency prediction

Bear Gulch near Hayward (06405800)

Beaver Creek near Pringle (06402430)

French Creek above Fairburn (06403300)

Spring Creek near Keystone (06407500)

0 35 5 10 15 20 25 30

8

-2

0

2

4

6

0 35 5 10 15 20 25 30

40

-10

0

10

20

30

0 35 5 10 15 20 25 30

40

-10

0

10

20

30

0 35 5 10 15 20 25 30

0 35 5 10 15 20 25 30

25

-5

0

5

10

15

20

-1

4

0

1

2

3

0 30 5 10 15 20 25

-20

80

0

20

40

60
Surface-Water Characteristics 73

Figure 43. Relations between annual streamflow and precipitation for crystalline core basins (from Driscoll and Carter, 

2001).—Continued

0 40 10 20 30

PRECIPITATION, IN INCHES

0 40 10 20 30

PRECIPITATION, IN INCHES

STREAMFLOW, IN CUBIC FEET PER SECOND

Linear regression

y = 2.415x - 35.97

r2 = 0.60

Exponential regression

y = 0.805e0.126x

r2 = 0.62

Runoff efficiency prediction

Linear regression

y = 0.307x - 5.15

r2 = 0.80

Exponential regression

y = 0.304e0.081x

r2 = 0.71

Runoff efficiency prediction

Linear regression

y = 0.363x - 6.52

r2 = 0.82

Exponential regression

y = 0.344e0.080x

r2 = 0.81

Runoff efficiency prediction

Linear regression

y = 0.880x - 13.90

r2 = 0.70

Exponential regression

y = 0.818e0.085x

r2 = 0.61

Runoff efficiency prediction

-1

5

0

1

2

3

4

Linear regression

y = 0.181x - 3.63

r2 = 0.82

Exponential regression

y = 0.056e0.109x

r2 = 0.75

Runoff efficiency prediction

Annie Creek near Lead (06430800)

Linear regression

y = 0.674x - 11.61

r2 = 0.79

Exponential regression

y = 0.472e0.091x

r2 = 0.72

Runoff efficiency prediction

Bear Butte Creek near Deadwood (06437020)

Boxelder Creek near Nemo (06422500)

Elk Creek near Roubaix (06424000)

Squaw Creek near Spearfish (06430898)

0 35 5 10 15 20 25 30

80

-20

0

20

40

60

-5

25

0

5

10

15

20

0 4 5 10 15 20 25 30 35 40 5

-2

10

0

2

4

6

8

Whitetail Creek at Lead (06436156)

0 45 5 10 15 20 25 30 35 40

0 45 5 10 15 20 25 30 35 40

-2

12

0

2

4

6

8

10

-5

25

0

5

10

15

20
74 Hydrology of the Black Hills Area, South Dakota

Figure 44. Relations between annual runoff efficiency and precipitation for crystalline core basins (from Driscoll and 

Carter, 2001).

5 10 15 20 25 30 35 40 45

PRECIPITATION, IN INCHES

0

60

10

20

30

40

50

RUNOFF EFFICIENCY, IN PERCENT

Beaver Creek (06402430)

French Creek (06403300)

Battle Creek (06404000)

Grace Coolidge Creek (06404998)

Bear Gulch (06405800)

Spring Creek (06407500)

Boxelder Creek (06422500)

Elk Creek (06424000)

Annie Creek (06430800)

Squaw Creek (06430898)

Whitetail Creek (06436156)

Bear Butte Creek (06437020)

Figure 45. Relations between annual streamflow and precipitation for loss zone basins (from Driscoll and Carter, 2001).

PRECIPITATION, IN INCHES

STREAMFLOW, IN CUBIC FEET PER SECOND

PRECIPITATION, IN INCHES

Spring Creek near Hermosa (06408500)

y = 1.013E-7*x5.892

r2 = 0.68

y = 9.782E-15*x10.469

r2 = 0.84

0 30 5 10 15 20 25

0

50

10

20

30

40

0 35 5 10 15 20 25 30

0

50

10

20

30

40

Boxelder Creek near Rapid City (06423010)
Surface-Water Characteristics 75

Table 7. Summary of regression information for artesian spring basins

[Regression information (from Driscoll and Carter, 2001) is provided for streamflow as a function of annual precipitation]

Station number Station name

Annual precipitation

r

2 p-value

06392950 Stockade Beaver Creek 0.16 0.135

06400497 Cascade Springs .07 .289

06402000 Fall River .003 .660

06402470 Beaver Creek above Buffalo Gap .49 .079

06429905 Sand Creek .04 .481

06430532 Crow Creek .39 .185

06430540 Cox Lake .55 .152

Driscoll and Carter (2001) identified a distinctive temporal trend in streamflow for the Fall River, 

which is composed almost entirely of artesian springflow. Peterlin (1990) investigated possible causes for 

declining streamflow that occurred during about 

1940-70 (fig. 46), but did not conclusively determine 

causes. Wet climatic conditions during the 1990’s have 

resulted in increased streamflow.

Relations between annual flow and precipitation 

for representative exterior basins are presented in 

figure 47. The p-values indicate that all correlations are 

statistically significant; however, the r2

 values generally are weak, relative to r2

 values for linear regressions 

for the crystalline core basins (fig. 43). A probable 

explanation is that crystalline core basins generally 

have larger base-flow components than exterior basins 

(table 5), which apparently are strongly influenced by 

annual precipitation amounts. In contrast, exterior 

basins are dominated by direct runoff, which is more 

responsive to event-oriented factors such as precipitation intensity.

Relations between annual runoff efficiency and 

precipitation for exterior basins are shown in figure 48. 

Runoff efficiencies generally increase with increasing 

precipitation, but efficiencies generally are lower than 

for the crystalline core basins (fig. 44) because of generally lower precipitation, increased evaporation 

potential, and minor irrigation withdrawals.

Figure 46. Long-term trends in annual streamflow for station 06402000 (Fall River near Hot Springs), 

relative to annual precipitation.

1920 1960 1930 1980 1940 1950 1970 1990 2000

WATER YEAR 

40

0

10

20

30

STREAMFLOW,

IN CUBIC FEET PER SECOND

40

30

0

10

20

PRECIPITATION, IN INCHES

Streamflow

Precipitation
76 Hydrology of the Black Hills Area, South Dakota

Figure 47. Relations between annual streamflow and precipitation for exterior basins (from Driscoll and Carter, 2001).

PRECIPITATION, IN INCHES

PRECIPITATION, IN INCHES

STREAMFLOW, IN CUBIC FEET PER SECOND

Hat Creek near Edgemont (06400000)

y = 2.657x - 25.89

r2 = 0.21

p-value = 0.001

y = 0.306x - 3.85

r2 = 0.49

p-value = 1.51E-7

y = 1.649x - 21.80

r2 = 0.49

p-value = 0.004

y = 3.923x - 39.65

r2 = 0.30

p-value = 0.012

y = 2.324x - 41.09

r2 = 0.69

p-value = 9.16E-8

0 25 5 10 15 20

0

120

20

40

60

80

100

Horsehead Creek at Oelrichs (06400875)

0 25 5 10 15 20

0

30

5

10

15

20

25

Hay Creek at Belle Fourche (06433500)

0 30 5 10 15 20 25

0

10

2

4

6

8

Indian Creek near Arpan (06436700)

0 25 5 10 15 20

0

100

20

40

60

80

Bear Butte Creek near Sturgis (06437500)

0 40 10 20 30

0

80

20

40

60
Surface-Water Characteristics 77

Annual Yield

Annual yield characteristics are highly variable 

throughout the study area, primarily because of orographic effects, which influence both precipitation and 

evapotranspiration. Selected information for gages 

used for analysis of basin yield is presented in table 8. 

With the exception of site 2 (station 06395000, 

Cheyenne River), all of the sites considered are representative gages for either the limestone headwater, 

crystalline core, or exterior hydrogeologic settings 

(table 5). Two of the representative gages from these 

settings (stations 06405800, Bear Gulch and 

06436700, Indian Creek) are excluded because annual 

yields may not be representative of areal conditions 

(Driscoll and Carter, 2001). All of the loss zone and 

artesian spring gages also are excluded.

Mean annual basin yields that are based on surface drainage areas for periods of measured record for 

selected gages are shown in figure 49. The largest 

yields occur in high-altitude areas of the northern Black 

Hills that receive large annual precipitation (fig. 4).

Large differences in annual yields are apparent 

for several of the limestone headwater basins, which 

results from incongruences between contributing 

ground- and surface-water areas. Mean annual yields 

for the four limestone headwater basins in South 

Dakota (sites 10, 11, 15, and 17; fig. 49) were estimated by Carter, Driscoll, Hamade, and Jarrell (2001) 

based on contributing ground-water areas. The contributing ground-water areas (fig. 50) were delineated by 

Jarrell (2000), based primarily on the structural orientation of the underlying Ordovician and Cambrian 

rocks. For the two limestone headwater basins in 

Wyoming (sites 1 and 14), relatively low yields indicate that contributing ground-water areas probably are 

smaller than the associated surface-water areas; however, estimates of contributing areas are not available.

Figure 48. Relations between annual runoff efficiency and precipitation for exterior basins (from Driscoll and Carter, 

2001).

0 5 10 15 20 25 30 35 40

PRECIPITATION, IN INCHES

0

12

2

4

6

8

10

RUNOFF EFFICIENCY, IN PERCENT

Hat Creek (06400000)

Horsehead Creek (06400875)

Hay Creek (06433500)

Indian Creek (06436700)

Bear Butte Creek (06437500)
78 Hydrology of the Black Hills Area, South Dakota Table 8. Summary of information used in analysis of yield characteristics [From Driscoll and Carter (2001). --, not applicable] Site number (fig. 49) Station number Station name Period of record (water years) Contributing area (square miles) Mean annual yield for period of record (inches) Mean annual yield efficiency3 1950-98 (percent) Surface water Ground water1 Surface water Ground water2 Surface water Ground water2 1 06392900 Beaver Creek at Mallo Camp 1975-82, 1992-98 10.3 (4) 2.48 -- 510.6 -- 2 06395000 Cheyenne River 1947-98 7,143 -- .15 -- 6.9 -- 3 06400000 Hat Creek 1951-98 1,044 -- .22 -- 1.3 -- 4 06400875 Horsehead Creek 1984-98 187 -- .49 -- 2.1 -- 5 06402430 Beaver Creek near Pringle 1991-98 45.8 -- .85 -- 1.8 -- 6 06403300 French Creek 1983-98 105 -- 1.42 -- 5.4 -- 7 06404000 Battle Creek 1962-98 58.0 -- 2.20 -- 8.3 -- 8 06404998 Grace Coolidge 1977-98 25.2 -- 2.73 -- 9.9 --

9 06407500 Spring Creek 1987-98 163 -- 2.09 -- 6.7 --

10 06408700 Rhoads Fork 1983-98 7.95 13.1 9.34 5.67 541.8 525.4

11 06409000 Castle Creek 1948-98 79.2 41.7 2.01 3.82 69.3 617.712 06422500 Boxelder Creek 1967-98 96.0 -- 2.76 -- 10.8 --13 06424000 Elk Creek 1992-98 21.5 -- 8.48 -- 21.5 --14 06429500 Cold Springs Creek 1975-82,

1992-98

19.0 (4) 3.10 -- 513.1 --

15 06430770 Spearfish Creek 1989-98 63.5 50.8 77.58 9.48 5,725.1 5,731.4

16 06430800 Annie Creek 1989-98 3.55 -- 6.55 -- 16.4 --17 06430850 Little Spearfish Creek 1989-98 25.8 25.4 8.74 8.88 531.8 532.318 06430898 Squaw Creek 1989-98 6.95 -- 7.34 -- 21.5 --19 06433500 Hay Creek 1954-96 121 -- .20 -- 1.0 --20 06436156 Whitetail Creek 1989-98 6.15 -- 10.57 -- 27.2 --21 06437020 Bear Butte Creek near Deadwood 1989-98 16.6 -- 6.84 -- 18.7 --22 06437500 Bear Butte Creek near Sturgis 1946-72 8120 -- 1.58 -- 6.0 --

1Estimate of contributing ground-water area from Carter, Driscoll, Hamade, and Jarrell (2001). 2Yield estimates, where applicable, adjusted based on contributing ground-water area. 3Estimated using relations between runoff efficiency and precipitation from Carter, Driscoll, and Hamade (2001), unless otherwise noted. 4Contributing areas for surface water and ground water probably not congruent; however, no estimates available. 5Estimated using average runoff efficiency for the available period of record. 6Period of record sufficient for computation of yield efficiency.7A flow of 10 cubic feet per second has been added to the measured streamflow to account for diverted flow. 8Approximate drainage area below loss zone. Actual drainage area is 192 square miles.
Surface-Water Characteristics 79

Figure 49. Basin yields for selected streamflow-gaging stations. For some stations, basin yields that are based on 

contributing ground-water areas estimated by Jarrell (2000) also are shown. Basin yields are for periods of record, which 

are not the same for all stations.

Creek

Creek

Cr

Beaver

Creek

Creek

Cold

Springs

Sand

Beaver Stockade

Whoopup

N. Fork Rapid Cr

Belle Fourche

Reservoir

FOURCHE

Victoria

Spring

Rhoads Fork

Coolidge

Highland

Angostura

Reservoir

Castl e Cr

N. Fork Castle Cr

Hell

Canyon

Canyon

Red

Bear

Gulch

Creek

Crow

Sheridan

Lake

Hot Brook Canyon

Cox

Lake

Deerfield

Reservoir

Pactola

Reservoir

Indian Cr

Horse

Creek

Owl

BELLE

Creek

RIVER

REDWATER

R I VER

Creek

Cr

Little Spearfish

Spearfish

Creek

Spearfish

Whitewood

Creek

Creek

Bear

Butte

Elk

Elk

Creek

Creek

Creek

Boxelder

Rapid

Rapid

Creek

Creek

Creek

Spring

Creek

French

Creek

Creek

Creek

Grace

Creek

Creek

Creek

S. Fork

Redbird

Gillette

S. Fork Rapid Cr

Battle

French

Beaver

Beaver

Creek

Creek

Creek

Creek

Creek

Fall R

Hat

Creek

Creek

Horsehead

CHEYENNE

RIVER

Cottonwood

Hay Creek

Bottom

False

Creek

Spokane

Lame

Johnny

Higgins

Beaver

Cr

Whitetail

Cr

Cr

Cr Cr

Gulch

Annie

Squaw

Deadwood

Creek

Alkali

Iron Cr

Elk

Little

Creek

Castle

Castle

Creek

Creek

Bear Gulch

Cr Strawberry

Boles

Canyon

Canyon

Canyon

Beaver Creek

Whitewood

Spearfish

Saint

Onge

DEADWOOD

Lead

BELLE FOURCHE

Newell

STURGIS

Blackhawk

Piedmont

Tilford

Box Elder 

Hill City

Hermosa

CUSTER

HOT SPRINGS

Edgemont

Minnekahta

Tinton Central

City

Roubaix

Nemo

Vale

Nisland

Hayward

Keystone

Rochford

Pringle

Fairburn

Buffalo Gap

Dewey

Cascade

Springs

Igloo

Provo

Oral

Rockerville

RAPID CITY

LIMESTONE PLATEAU

 Wind Cave

National Park

Jewel Cave

National

Monument

Mt. Rushmore

National

Memorial

CUSTER

STATE

PARK

Wind

Cave

Harney

Peak

x

Ellsworth

Air Force

Base

BUTTE CO

LAWRENCE CO MEADE CO

PENNINGTON CO

CUSTER CO

FALL RIVER CO

WYOMING

SOUTH DAKOTA

2

3

4

5

6

7

8

9

10 12

11

15 13

14

1

16 17

18

19

20 21

22

2

3

4

5

6

7

8

9

10 12

11

15 13

14

1

16

17

18

19

20 21

22

11

2.01

3.82

1.58

0.20

7.34

8.74

8.88

6.55

7.58

9.48

10.57

6.84

8.48

3.10

2.48

9.34

5.67

2.01

3.82

2.76

2.09

2.20

2.73

1.42

0.85

0.15

0.22

0.49

1.58

0.20

7.34

8.74

8.88

6.55

7.58

9.48

10.57

6.84

8.48

3.10

2.48

9.34

5.67

2.01

3.82

2.76

2.09

2.20

2.73

1.42

0.85

0.15

0.22

0.49

OUTCROP OF MADISON LIME-

 STONE (from Strobel and

 others, 1999)

OUTCROP OF THE MINNELUSA

 FORMATION (from Strobel

 and others, 1999)

STREAMFLOW-GAGING

 STATION--Number indicates

 site number from table 8. Red

 number indicates mean annual

 basin yield, in inches, based on

 surface-water drainage area.

 Green number (where applica-

 ble) indicates mean annual basin

 yield, in inches, based on

 estimated contributing ground-

 water area

EXPLANATION

104o 45' 103o

30'

15' 103o

30'

44o45'

15'

44o

45'

30'

43o

15'

0 10 20

0 10 20 MILES

KILOMETERS

Base modified from U.S. Geological Survey digital data,

1:100,000, 1977, 1979, 1981, 1983, 1985

Rapid City, Office of City Engineer map, 1:18,000, 1996

Universal Transverse Mercator projection, zone 13
80 Hydrology of the Black Hills Area, South Dakota

Figure 50. Comparison between surface-drainage areas and contributing ground-water areas for streamflow-gaging 

stations in Limestone Plateau area (modified from Jarrell, 2000). Streamflow in the basins shown generally is dominated 

by ground-water discharge of headwater springs. Recharge occurring in areas west of the ground-water divide does not 

contribute to headwater springflow east of the divide. Little

Spearfish

Spearfish

Creek

Creek

Creek

Castle

Castle

Castle

Castle

Creek

Creek

Spring

French

Creek

Creek

N. Fork

S. Fork

N. Fork

S. Fork

Rapid

Rapid

Rapid

Rhoads Fork

Creek

Cr

Squaw

Annie

Creek

Cr

Creek

Creek

Deerfield

Reservoir

Pactola

Reservoir

Sheridan

Lake

Stockade

Lake Red Canyon

Boles

Gillette

Canyon

Canyon

Redbird

Canyon

Cold Springs Creek

Creek

Beaver

Lead

Hill City

CUSTER

Cheyenne

Crossing

Rochford

LAWRENCE COUNTY

PENNINGTON COUNTY

CUSTER COUNTY

LIMESTONE PLATEAU

06430850

06430770

06408700

06409000

06408700

EXPLANATION

1 2 3 4 MILES 5

0 1234 5 KILOMETERS

0

44o15'

44o

43o45'

103o

45'

104o

103o30'

CONTRIBUTING GROUND-

 WATER AREAS

STREAMFLOW-GAGING

 STATION—Number is

 station number

Rhoads Fork near Rochford

 (06408700)

Castle Creek above Deerfield

 Reservoir (06409000)

Spearfish Creek near Lead

 (06430770)

Little Spearfish Creek near

 Lead (06430850)

SOUTH DAKOTA

Study

area

Area

shown

SURFACE-AREA DRAINAGE

 AREA

OUTCROP OF DEADWOOD

 FORMATION, ENGLEWOOD

 FORMATION, MADISON

 LIMESTONE, AND MINNELUSA

 FORMATION (modified from

 Strobel and others, 1999)

ESTIMATED GROUND-WATER

 DIVIDE FOR THE MADISON

 AQUIFER (modified from 

 Jarrell, 2000)

Base modified from U.S. Geological Survey digital data,

1:100,000, 1977, 1979, 1981, 1983, 1985

Rapid City, Office of City Engineer map, 1:18,000, 1996

Universal Transverse Mercator projection, zone 13
Surface-Water Characteristics 81

The approximate location of a ground-water 

divide that was identified by Jarrell (2000) also is 

shown in figure 50. This divide coincides with the 

western extent of the contributing ground-water areas 

for the four gaging stations that are shown. West of the 

ground-water divide, infiltration of precipitation 

results in ground-water recharge that is assumed to 

flow to the west, contributing to regional flowpaths in 

the Madison and Minnelusa aquifers that wrap around 

the northern or southern flanks of the uplift (fig. 17). 

East of the divide, recharge is assumed to contribute to 

headwater springflow along the eastern flank of the 

Limestone Plateau.

The ground-water divide extends about 10 mi 

south of the Castle Creek Basin and approximately 

coincides with the western extent of the Spring and 

French Creek drainage areas in this vicinity. The 

ground-water divide is not defined south of this point 

because the surface drainages contribute to Red 

Canyon, which flows to the south and provides streamflow recharge to the Madison and Minnelusa aquifers 

along the western flank of the uplift. Westerly groundwater flow directions are not possible immediately 

north of the ground-water divide because the Madison 

and Minnelusa aquifers are absent in the vicinity of 

Tertiary intrusive units (fig. 14).

After adjusting for contributing ground-water 

areas, annual yields for the limestone headwater basins 

(table 8; fig. 49) generally are consistent with a pattern 

of increasing yields corresponding with increasing 

annual precipitation (fig. 4). Adjusted yields for limestone headwater basins, which are dominated by 

ground-water discharge, also are generally similar to 

yields for nearby streams that are dominated by surface 

influences. These similarities were used by Carter, 

Driscoll, and Hamade (2001) in developing a method 

for estimating precipitation recharge to the Madison 

and Minnelusa aquifers. An important initial assumption was that in areas of comparable precipitation, 

evapotranspiration in outcrops of the Madison and 

Minnelusa Formations is similar to evapotranspiration 

for crystalline core settings, where recharge to regional 

flow systems is considered negligible. A further 

assumption was made that direct runoff is negligible 

for Madison and Minnelusa outcrops, which is supported by the daily flow characteristics for the limestone headwater setting. These assumptions resulted in 

a concept that streamflow yield in the crystalline core 

setting can be used as a surrogate for the efficiency of 

precipitation recharge to the Madison and Minnelusa 

aquifers. This concept is schematically illustrated in 

figure 51.

Figure 51. Schematic diagram illustrating recharge and streamflow characteristics for selected outcrop types 

(from Carter, Driscoll, and Hamade, 2001).

PRECIPITATION

MADISON

AND

MINNELUSA

OUTCROPS

CRYSTALLINE

CORE

STREAMFLOW = 0

EVAPOTRANSPIRATION

PRECIPITATION

RECHARGE

TO REGIONAL FLOW SYSTEM

RECHARGE

TO REGIONAL FLOW SYSTEM = 0

STREAMFLOW
82 Hydrology of the Black Hills Area, South Dakota

Carter, Driscoll, and Hamade (2001) used estimates of average runoff efficiencies for 1950-98 to 

develop a map of generalized yield efficiency for the 

study area (fig. 52). Where applicable, estimated yield 

efficiencies shown in figure 52 are representative of 

estimated yield efficiencies for the contributing 

ground-water areas. For basins where contributing 

surface- and ground-water areas are assumed to be congruent, yield efficiency is considered equivalent to 

runoff efficiency. For areas where direct runoff is negligible, yield efficiency is considered equivalent to the 

efficiency of precipitation recharge. For many gages, 

estimation of average yield efficiencies for this period 

required extrapolation of incomplete streamflow 

records (table 5) using precipitation records. Records 

were extrapolated to compensate for bias resulting 

from short-term records for many gages that are 

skewed towards wet climatic conditions during the 

1990’s. Yield efficiencies for most of the limestone 

headwater gages are simply averages for the available 

periods of record, because relations between streamflow and precipitation for this setting generally are very 

weak or unrealistic.

Carter, Driscoll, and Hamade (2001) also considered precipitation patterns and topography in contouring yield efficiencies, which provide a reasonable 

fit with calculated efficiencies (fig. 52). Estimates of 

contributing areas are not available for the two limestone headwater gages in Wyoming (sites 1 and 14); 

thus, yield efficiencies could not be adjusted. For 

Annie Creek (site 16), the calculated yield efficiency 

(16.4 percent) is lower than for other nearby streams, 

which may result from extensive mining operations 

that utilize substantial quantities of water through 

evaporation for heap-leach processes. For Hay Creek 

(site 19), the calculated yield efficiency (1.0 percent) is 

notably lower than the mapped contours, which probably results from precipitation recharge to outcrops of 

the Inyan Kara Group (fig. 14).

Carter, Driscoll, and Hamade (2001) used relations between yield efficiency and precipitation in 

developing a GIS algorithm for systematically estimating annual recharge from infiltration of precipitation, based on annual precipitation on outcrop areas. 

Linear regression and best-fit exponential equations 

were determined for 11 basins, which include all of the 

representative crystalline basins (table 5) except Bear 

Gulch. Exponential equations were in the form of:

(1)

where

YEannual = annual yield efficiency, in percent;

Pannual = annual precipitation, in inches;

Paverage = average annual precipitation for 

1950-98, in inches;

YEaverage = average annual yield efficiency for 

1950-98, in percent; and

n = exponent.

Best-fit exponents ranged from 1.1 for Elk Creek 

to 2.5 for Spring Creek. An exponent of 1.6 was chosen 

as best representing the range of best-fit exponents 

(Carter, Driscoll, and Hamade, 2001), which allowed a 

systematic approach to estimation of annual recharge. 

Scatter plots with the linear regression lines, best-fit 

exponential curves, and exponential curves using an 

exponent of 1.6 are shown in figure 53. The three 

methods provide very similar results through the midrange of measured precipitation values, with the largest 

differences occurring for the upper part of the range.

The spatial distribution of average annual yield 

potential for the Black Hills area is shown in figure 54. 

Average annual recharge from infiltration of precipitation on outcrops of the Madison Limestone and 

Minnelusa Formation is shown as an example. Estimates were derived by Carter, Driscoll, and Hamade 

(2001) using a GIS algorithm that compared digital 

grids (1,000-by-1,000 meters, including outcrop areas 

in Wyoming) for annual precipitation, average annual 

precipitation (fig. 4), and average annual yield efficiency (fig. 53). Annual recharge rates for individual 

grid cells ranged from 0.4 inch at the southern 

extremity of the outcrops to 8.7 inches in the northern 

Black Hills. Although this “yield-efficiency algorithm” 

was developed initially for estimating precipitation 

recharge for the Madison and Minnelusa aquifers, 

applications for estimating streamflow yield and 

recharge for other aquifers also are appropriate and are 

used later in this report.

Water Quality

This section summarizes water-quality characteristics for surface water within the study area. More 

detailed discussions are presented by Williamson and 

Carter (2001). Standards and criteria that apply to surface waters are presented in the following section, after 

which common-ion characteristics, anthropogenic 

effects on water quality, and additional factors relative 

to in-stream standards are discussed.

YEannual

Pannual

Paverage

------------------- n

YEaverage = ×
Surface-Water Characteristics 83

Figure 52. Generalized average annual yield efficiency (in percent of annual precipitation), water years 1950-98 (from 

Carter, Driscoll, and Hamade, 2001).

N. Fork Rapid Cr

Belle Fourche

Reservoir

FOURCHE

Victoria

Spring

Rhoads Fork

Coolidge

Highland

Angostura

Reservoir

Castl e Cr

N. Fork Castle Cr

Hell

Canyon

Canyon

Red

Bear

Gulch

Creek

Crow

Sheridan

Lake

Hot Brook Canyon

Cox

Lake

Deerfield

Reservoir

Pactola

Reservoir

Indian Cr

Horse

Creek

Owl

BELLE

Creek

RIVER

REDWATER

R I VER

Creek

Cr

Little Spearfish

Spearfish

Creek

Spearfish

Whitewood

Creek

Creek

Bear

Butte

Elk

Elk

Creek

Creek

Creek

Boxelder

Rapid

Rapid

Creek

Creek

Creek

Spring

Creek

French

Creek

Creek

Creek

Grace

Creek

Creek

Creek

S. Fork

Redbird

Gillette

S. Fork Rapid Cr

Battle

French

Beaver

Beaver

Creek

Creek

Creek

Creek

Creek

Fall R

Hat

Creek

Creek

Horsehead

CHEYENNE

RIVER

Cottonwood

Hay Creek

Bottom

False

Creek

Spokane

Lame

Johnny

Higgins

Beaver

Cr

Whitetail

Cr

Cr

Cr Cr

Gulch

Annie

Squaw

Deadwood

Creek

Alkali

Iron Cr

Elk

Little

Creek

Castle

Castle

Creek

Creek

Bear Gulch

Cr Strawberry

Boles

Canyon

Canyon

Canyon

Beaver Creek

Creek

Creek

Cr

Beaver

Creek

Creek

Cold

Springs

Sand

Beaver Stockade

Whoopup

Whitewood

Spearfish

Saint

Onge

DEADWOOD

Lead

BELLE FOURCHE

Newell

STURGIS

Blackhawk

Piedmont

Tilford

Box Elder 

Hill City

Hermosa

CUSTER

HOT SPRINGS

Edgemont

Minnekahta

Tinton Central

City

Roubaix

Nemo

Vale

Nisland

Hayward

Keystone

Rochford

Pringle

Fairburn

Buffalo Gap

Dewey

Cascade

Springs

Igloo

Provo

Oral

Rockerville

RAPID CITY

LIMESTONE PLATEAU

 Wind Cave

National Park

Jewel Cave

National

Monument

Mt. Rushmore

National

Memorial

CUSTER

STATE

PARK

Wind

Cave

Harney

Peak

x

Ellsworth

Air Force

Base

BUTTE CO

LAWRENCE CO MEADE CO

PENNINGTON CO

CUSTER CO

FALL RIVER CO

WYOMING

SOUTH DAKOTA

4

6

30

25

20

8

15

10

10

8

6

6

4

4

2

2

1

2

0.9 3

1.3 4

2.1

5

1.8

6

5.4

7

8.3

8

9.9

9

6.7

10

25.4

12

10.8

11

17.7

13

21.5

14

13.1

1

10.6

16

16.4 15

31.4

17

32.3

18

21.5

19

1.0

20

27.2

21

18.7

22

6.0

2

0.9 3

1.3 4

2.1

5

1.8

6

5.4

7

8.3

8

9.9

9

6.7

10

25.4

12

10.8

11

17.7

13

21.5

14

13.1

1

10.6

16

16.4 15

31.4

17

32.3

18

21.5

19

1.0

20

27.2

21

18.7

22

6.0

104o 45' 103o

30'

15' 103o

30'

44o

45'

15'

44o

45'

30'

43o

15'

0 10 20

0 10 20 MILES

KILOMETERS

EXPLANATION

LINE OF EQUAL AVERAGE

 ANNUAL YIELD EFFICIENCY--

 Interval 1, 2, or 5 percent

15

OUTCROP OF MADISON LIME-

 STONE (from Strobel and

 others, 1999)

OUTCROP OF MINNELUSA

 FORMATION (from Strobel

 and others, 1999)

STREAMFLOW-GAGING

 STATION--Numbers indicate

 site number from table 6 and 

 estimated yield efficiency, in

 percent, for water years

 1950-98. (Yield efficiencies

 for contributing ground-water

 areas shown where applicable)

3

1.3

Base modified from U.S. Geological Survey digital data,

1:100,000, 1977, 1979, 1981, 1983, 1985

Rapid City, Office of City Engineer map, 1:18,000, 1996

Universal Transverse Mercator projection, zone 13
84 Hydrology of the Black Hills Area, South Dakota

Figure 53. Relations between yield efficiency and precipitation for selected streamflow-gaging stations (modified from 

Carter, Driscoll, and Hamade, 2001). YIELD EFFICIENCY, IN PERCENT YIELD EFFICIENCY, IN PERCENT YIELD EFFICIENCY, IN PERCENT

ANNUAL PRECIPITATION, IN INCHES

0

8

2

4

6

Beaver Creek near Pringle (06402430)

0

20

5

10

15

French Creek above Fairburn (06403300)

0 35 5 10 15 20 25 30

0 35 5 10 15 20 25 30

0 35 5 10 15 20 25 30

ANNUAL PRECIPITATION, IN INCHES

0

25

05

10

15

20

Battle Creek near Keystone (06404000)

Best-fit exponent = 1.9

Best-fit exponent = 1.6

Best-fit exponent = 2.2

0 35 5 10 15 20 25 30

0

40

10

20

30

Grace Coolidge Creek near Game Lodge, near Custer

(06404998)

0 30 5 10 15 20 25

0

20

05

10

15

Spring Creek near Keystone (06407500)

Best-fit exponent = 2.5

Best-fit exponent = 1.9

0 35 5 10 15 20 25 30

0

30

10

20

Boxelder Creek near Nemo (06422500)

Best-fit exponent = 2.1
Surface-Water Characteristics 85

Figure 53. Relations between yield efficiency and precipitation for selected streamflow-gaging stations (modified from 

Carter, Driscoll, and Hamade, 2001).—Continued YIELD EFFICIENCY, IN PERCENT YIELD EFFICIENCY, IN PERCENT YIELD EFFICIENCY, IN PERCENT

ANNUAL PRECIPITATION, IN INCHES

0

0 40 5 10 15 20 25 30 35

0

40

10

20

30

Elk Creek near Roubaix (06424000)

5 10 15 20 25 30 35 40

0

50

10

20

30

40

Annie Creek near Lead (06430800)

Best-fit exponent = 2.1

Best-fit exponent = 1.1

0 45 5 10 15 20 25 30 35 40

0

50

10

20

30

40

Squaw Creek near Spearfish (06430898)

Best-fit exponent = 1.3

ANNUAL PRECIPITATION, IN INCHES

0 45 5 10 15 20 25 30 35 40

0 45 5 10 15 20 25 30 35 40

0

60

20

10

40

30

50

Whitetail Creek at Lead (06436156)

0

50

10

20

30

40

Bear Butte Creek near Deadwood (06437020)

Best-fit exponent = 1.4

Best-fit exponent = 1.4

LINEAR REGRESSION

EXPONENTIAL REGRESSION USING AN

 EXPONENT OF 1.6

BEST FIT EXPONENTIAL REGRESSION

EXPLANATION
86 Hydrology of the Black Hills Area, South Dakota

Figure 54. Estimated annual yield potential for the Black Hills area, water years 1950-98 (from Carter, Driscoll, and 

Hamade, 2001). Average annual recharge from precipitation on outcrops of the Madison Limestone and Minnelusa 

Formation is shown as an example.

Redwater

Creek

Inyan Kara

Creek

Creek

Beaver

CHEYENNE

RIVER

Creek

Lance

N. Fork Rapid Cr

Belle Fourche

Reservoir

FOURCHE

Victoria

Spring

Rhoads Fork

Coolidge

Highland

Angostura

Reservoir

Castl e Cr

N. Fork Castle Cr

Hell

Canyon

Canyon

Red

Bear

Gulch

Creek

Crow

Sheridan

Lake

H ot Brook Canyon

Cox

Lake

Deerfield

Reservoir

Pactola

Reservoir

Indian Cr

Horse

Creek

Owl

BELLE

Creek

RIVER

REDWATER

R I VER

Creek

Cr

Little Spearfish

Spearfish

Creek

Spearfish

Whitewood

Creek

Creek

Bear

Butte

Elk

Elk

Creek

Creek

Creek

Boxelder

Rapid

Rapid

Creek

Creek

Creek

Spring

Creek

French

Creek

Creek

Creek

Grace

Creek

Creek

Creek

S. Fork

Redbird

Gillette

S. Fork Rapid Cr

Battle

French

Beaver

Beaver

Creek

Creek

Creek

Creek

Creek

Fall R

Hat

Creek

Creek

Horsehead

CHEYENNE

RIVER

Cottonwood

Hay Creek

Bottom

False

Creek

Spokane

Lame

Johnny

Higgins

Beaver

Cr

Whitetail

Cr

Cr

Cr Cr

Gulch

Annie

Squaw

Deadwood

Creek

Alkali

Iron Cr

Elk

Little

Creek

Castle

Castle

Creek

Creek

Bear Gulch

Cr Strawberry

Boles

Canyon

Canyon

Canyon

Sundance

Beulah

Newcastle

Whitewood

Spearfish

Saint

Onge

DEADWOOD

Lead

BELLE FOURCHE

Newell

STURGIS

Blackhawk

Piedmont

Tilford

Box Elder 

Hill City

Hermosa

CUSTER

HOT SPRINGS

Edgemont

Minnekahta

Tinton Central

City

Roubaix

Nemo

Vale

Nisland

Hayward

Keystone

Rochford

Pringle

Fairburn

Buffalo Gap

Dewey

Cascade

Springs

Igloo

Provo

Oral

Rockerville

RAPID CITY

LIMESTONE PLATEAU

 Wind Cave

National Park

Jewel Cave

National

Monument

Mt. Rushmore

National

Memorial

CUSTER

STATE

PARK

Wind

Cave

Harney

Peak

x

Ellsworth

Air Force CROOK CO Base

WESTON CO

NIOBRARA CO

104o 104o

30' 103o

30'

103o

44o30'

44o

43o30'

BUTTE CO

LAWRENCE CO MEADE CO

PENNINGTON CO

CUSTER CO

FALL RIVER CO

WYOMING

SOUTH DAKOTA

8

7

7

6

6

5

5

2

4

4

3

3

2

2

1

1

1

0 10 20

0 10 20 MILES

KILOMETERS

EXPLANATION

CONNECTED OUTCROP OF MADISON LIMESTONE FOR WHICH

 PRECIPITATION RECHARGE IS PRESCRIBED (modified from

 Strobel and others, 1999; DeWitt and others, 1989)

AVERAGE ANNUAL RECHARGE, IN INCHES

Less than 1

1 to 2

2 to 3

3 to 4

4 to 5

5 to 6

6 to 7

7 to 8

8 to 9

CONNECTED OUTCROP OF MINNELUSA FORMATION FOR WHICH

PRECIPITATION RECHARGE IS PRESCRIBED (modified from

 Strobel and others, 1999; DeWitt and others, 1989)

LINE OF EQUAL YIELD POTENTIAL--Number indicates

 average annual yield potential. Interval 1 inch

2

Base modified from U.S. Geological Survey digital data, 1:100,000, 1977, 1979, 1981, 1983, 1985

Rapid City, Office of City Engineer map, 1:18,000, 1996; Universal Transverse Mercator projection, zone 13

SOUTH DAKOTA

WYOMING

Area

Black shown

Hills

Creek

Cr

Beaver

Creek

Creek

Cold

Springs

Sand

Stockade

Whoopup
Surface-Water Characteristics 87

Standards and Criteria

Most water-quality standards for surface water 

are determined by the applicable beneficial-use criteria 

(table 9) established for individual stream reaches. All 

streams in South Dakota are designated for the beneficial uses of irrigation and of wildlife propagation and 

stock watering. Additional beneficial uses are assigned 

to stream segments as applicable. Designated beneficial uses for specific stream segments are indicated by 

South Dakota Department of Environment and Natural 

Resources (2001a). Aquatic-life criteria are estimates 

of the highest constituent concentrations that aquatic 

life can be exposed to without adverse effects. The 

chronic criteria are based on extended exposures, and 

acute criteria are based on very short-term exposures. 

The aquatic criteria for several trace elements vary with 

stream hardness, as shown in figure 55. Drinking-water 

standards apply only to finished waters that are used for 

public consumption. These standards do provide 

another useful basis for comparison, however, and 

were presented previously in table 4.

Common-ion Chemistry

Common-ion chemistry of surface water in the 

study area is highly influenced by geology. Within this 

section, distinctive water-quality characteristics are 

described for the hydrogeologic settings (limestone 

headwater, crystalline core, artesian spring, and exterior settings) that were discussed previously (fig. 23). 

The loss zone setting is not characterized because the 

primary hydrologic influence is on streamflow, not 

water quality. Site information for sampling sites representative of the hydrogeologic settings was presented 

previously in table 5.

Specific conductance can provide an excellent 

indication of dissolved solids concentrations in surface 

water (fig. 56). Results of regression analyses (dissolved solids versus specific conductance) for samples 

available for sites representative of hydrogeologic settings are presented in table 10. Correlations between 

dissolved solids and specific conductance are strong 

for all of the hydrogeologic settings except the limestone headwater setting, for which variability in dissolved solids concentrations is small. Table 10 also 

includes regression information for all available 

samples for surface-water sites within the study area 

considered by Williamson and Carter (2001), which 

include numerous sites in addition to those that are representative of the hydrogeologic settings. The equation 

provided for all samples generally should provide reasonable estimates of dissolved solids concentrations 

(based on specific conductance) for surface water 

within the study area, regardless of hydrogeologic conditions. This equation would be most appropriate for 

locations where water quality is influenced by multiple 

hydrogeologic settings, which is a common circumstance within the study area.

Relations between specific conductance and 

streamflow for the hydrogeologic settings are shown in 

figure 57. Because of the large number of sites representative of the crystalline core setting, only five sites 

are shown for this setting. Measurements of specific 

conductance are abundant because measurements typically are obtained at USGS streamflow-gaging stations 

when streamflow is measured.

Sites representative of the crystalline core and 

exterior settings have large variability in streamflow 

and exhibit generally inverse relations between specific 

conductance and streamflow (fig. 57). Specific conductance values (and dissolved solids concentrations) 

generally decrease with increasing streamflow, primarily because of dilution by direct runoff.

Streamflow variability generally is small for the 

limestone headwater and artesian spring settings 

(fig. 57) because of dominance by ground-water discharge. Specific conductance values are nearly identical for all of the limestone headwater sites, where the 

primary geologic influences are outcrops of the 

Madison Limestone or outcrops of the Minnelusa 

Formation in areas where anhydrite beds have been 

removed by dissolution over geologic time.

Specific conductance characteristics are fairly 

distinct for each of the artesian spring sites (fig. 57). 

The lowest specific conductance values generally are 

for Cleghorn Springs, which is located within an outcrop of the Minnelusa Formation (fig. 35). The other 

artesian spring sites reflect larger influence from anhydrite beds within the Minnelusa Formation or possibly 

from dissolution of sulfate within other overlying geologic units. Minor influences (reduced specific conductance values) from occasional runoff events are 

apparent for several sites.
88 Hydrology of the Black Hills Area, South Dakota Table 9. Surface-water-quality standards for selected physical properties and constituents [All constituents in milligrams per liter unless otherwise noted. μS/cm, microsiemens per centimeter at 25 degrees Celsius; μg/L, micrograms per liter; oF, degrees Fahrenheit; oC, degrees Celsius; >, greater than or equal to; --, no data available] Property or constituent Beneficial-use criteria1 Aquatic-life criteria for fisheries1 (acute/ chronic)

(μg/L)

Domestic 

water supply

(mean/daily 

maximum)

Coldwater

permanent

fisheries

Coldwater

marginal

fisheries

Warmwater

permanent

fisheries

Warmwater

semipermanent

fisheries

Warmwater

marginal 

fisheries

Immersion

waters

Limitedcontact

waters

Wildlife

propagation

and stockwatering

waters

Irrigation

waters

Specific conductance 

(μS/cm)

-- -- -- -- -- -- -- -- 24,000/7,000 22,500/4,375 --

pH range (standard 

units)

6.5-9.0 6.6-8.6 6.5-8.8 6.5-9 6.5-9 6.5-9 -- -- 6.0-9.5 -- --

Temperature oF/oC 

(maximum)

-- 65/18.3 75/24 80/27 90/32 90/32 -- -- -- -- --

Dissolved oxygen

(minimum)

-- >6.0

>7 during 

spawning

>5.0 >5.0 >5.0 >4.0 >5.0 >5.0 -- -- --

Total dissolved solids 21,000/1,750 -- -- -- -- -- -- -- 22,500/4,375 -- --

Total suspended solids -- 230/53 290/158 290/158 290/158 2150/263 -- -- -- -- --

Sodium-adsorption ratio -- -- -- -- -- -- -- -- -- 10 --Chloride 2250/438 2100/175 -- -- -- -- -- -- -- -- --

Fluoride 4.0 -- -- -- -- -- -- -- -- -- --Sulfate 2500/875 -- -- -- -- -- -- -- -- -- --

Nitrate (as N) 10 -- -- -- -- -- -- -- 250/88 -- --Un-ionized ammonia

(as N)

-- 0.02 0.02 0.04 0.04 0.05 -- -- -- -- --

Cyanide (free) -- -- -- -- -- -- -- -- -- -- 22/5.2Dissolved arsenic -- -- -- -- -- -- -- -- -- -- 360/190Dissolved barium 1.0 -- -- -- -- -- -- -- -- -- --Dissolved cadmium -- -- -- -- -- -- -- -- -- -- 33.7/31.0

Dissolved copper -- -- -- -- -- -- -- -- -- -- 317/ 311

Dissolved lead -- -- -- -- -- -- -- -- -- -- 365/ 32.5

Dissolved mercury -- -- -- -- -- -- -- -- -- -- 2.1/ 40.012

Dissolved selenium -- -- -- -- -- -- -- -- -- -- 20/5Dissolved zinc -- -- -- -- -- -- --- -- -- -- 3110/ 3100

1South Dakota Department of Environment and Natural Resources (2001a). 230-day average/daily maximum.3Hardness-dependent criteria; value given is an example based on hardness of 100 milligrams per liter as CaCO3. 4Chronic criteria based on total recoverable concentration.
Surface-Water Characteristics 89

Figure 55. Relations between hardness and freshwater aquatic-life standards for acute and chronic 

toxicity of selected trace elements (South Dakota Department of Environment and Natural Resources, 

1998).

1

10,000

2

3

4

5

7

10

20

30

40

50

70

100

200

300

400

500

700

1,000

2,000

3,000

4,000

5,000

7,000

DISSOLVED TRACE-ELEMENT CONCENTRATION, IN MICROGRAMS PER LITER

100 200 300 400 500 600 700 800 900 1,000 1,100 1,200

HARDNESS, IN MILLIGRAMS PER LITER

1

10,000

2

3

4

5

7

10

20

30

40

50

70

100

200

300

400

500

700

1,000

2,000

3,000

4,000

5,000

7,000

EXPLANATION

CADMIUM

COPPER

LEAD

SILVER

NICKEL

ZINC

Acute criterion

Chronic criterion
90 Hydrology of the Black Hills Area, South Dakota

Table 10. Summary of regression information (dissolved solids versus specific conductance), by 

hydrogeologic setting

[S = dissolved solids, in milligrams per liter; K = specific conductance, in microsiemens per centimeter]

Hydrogeologic setting Equation of line r2 Number of samples

Headwater spring S = 0.21K + 158.16 0.2437 261

Crystalline core S = 0.55K + 15.83 .8914 136

Artesian spring S = 0.93K - 194.22 .9614 13

Exterior S = 0.85K - 249.50 .9676 174

All1 S = 0.86K - 131.14 .9692 12,355

1

Includes numerous surface-water samples in addition to those available for sites representative of hydrogeologic 

settings.

Figure 56. Relations between dissolved solids and specific conductance by hydrogeologic 

settings (from Williamson and Carter, 2001).

0 2,000 4,000 6,000 8,000 10,000

SPECIFIC CONDUCTANCE,

IN MICROSIEMENS PER CENTIMETER

0

7,500

500

1,000

1,500

2,000

2,500

3,000

3,500

4,000

4,500

5,000

5,500

6,000

6,500

7,000

DISSOLVED SOLIDS, IN MILLIGRAMS PER LITER

Limestone headwater

Crystalline core

Artesian spring

Exterior
Surface-Water Characteristics 91Figure 57. Relations between specific conductance and streamflow for selected sampling sites by hydrogeologic setting (from Williamson and Carter, 2001).

0.001 10,000 0.01 0.1 1 10 100 1,000

10

10,000

7050403020

700500400300200100

7,0005,0004,0003,0002,0001,000

LIMESTONE HEADWATER

Rhoads Fork (06408700)

Castle Creek (06049000)Spearfish Creek (06430770)Little Spearfish Creek (06430850)

0.001 10,000 0.01 0.1 1 10 100 1,000

10

10,000

7050403020

700500400300200100

7,0005,0004,0003,0002,0001,000

ARTESIAN SPRING

Cascade Springs (06400497)

Fall River (06402000)Beaver Creek (06402470)Cleghorn Springs (06412810)Crow Creek (06430532)Cox Lake (06430540)

0.001 10,000 0.01 0.1 1 10 100 1,000

10

10,000

7050403020

700500400300200100

7,0005,0004,0003,0002,0001,000

CRYSTALLINE CORE (subset of 14 sites)

Battle Creek (06404000)

Grace Coolidge Creek (06404998)Spring Creek (06407500)

Boxelder Creek (06422500)Squaw Creek (06430898)

0.001 10,000 0.01 0.1 1 10 100 1,000

STREAMFLOW, IN CUBIC FEET PER SECOND

10

10,000

7050403020

700500400300200100

7,0005,0004,0003,0002,0001,000

EXTERIOR

Cheyenne River (06395000)

Hat Creek (06400000)Hay Creek (06433500)Horse Creek (06436760)

SPECIFIC CONDUCTANCE, IN MICROSIEMENS PER CENTIMETER
92 Hydrology of the Black Hills Area, South Dakota

Trilinear diagrams showing ionic proportions 

(by hydrogeologic setting) for available samples for 

representative sites are shown in figure 58. Median 

concentrations for each setting are shown in figure 59. 

Proportions of common ions are similar for some sites 

representative of the limestone headwater and crystalline core settings (fig. 58); however, many of the crystalline core sites have smaller proportions of 

bicarbonate and larger proportions of chloride than 

limestone headwater sites. The limestone headwater 

and crystalline core settings have the lowest median 

concentrations of common ions (fig. 59), which is consistent with low concentrations of dissolved solids, 

relative to the artesian spring and exterior settings 

(fig. 56).

Figure 58. Trilinear diagrams showing proportional concentrations of common ions by hydrogeologic setting (from 

Williamson and Carter, 2001).

Calcium + Magnesium

Sulfate

Sodium + Potassium

Chloride + Fluoride + Nitrate + Sulfate

Bicarbonate + Carbonate

Magnesium

Calcium Chloride + Fluoride + Nitrate

80

60

40

20

80

80

60

40

20

20

20

40

6080

40

60

80

60

40

20

20

80

60

40

20

40

60

80

80

60

40

20

LIMESTONE HEADWATER

Calcium + Magnesium

Sulfate

Sodium + Potassium

Chloride + Fluoride + Nitrate + Sulfate

Bicarbonate + Carbonate

Magnesium

Calcium Chloride + Fluoride + Nitrate

80

60

40

20

80

80

60

40

20

20

20

40

60

80

40

60

80

60

40

20

20

80

60

40

20

40

60

80

80

60

40

20

ARTESIAN SPRING

Calcium + Magnesium

Sulfate

Sodium + Potassium

Chloride + Fluoride + Nitrate + Sulfate

Bicarbonate + Carbonate

Magnesium

Calcium Chloride + Fluoride + Nitrate

PERCENT OF REACTING VALUES PERCENT OF REACTING VALUES

PERCENT OF REACTING VALUES PERCENT OF REACTING VALUES

80

60

40

20

80

80

60

40

20

20

20

40

60

80

40

60

80

60

40

20

20

80

60

40

20

40

60

80

80

60

40

20

CRYSTALLINE CORE

Calcium + Magnesium

Sulfate

Sodium + Potassium

Chloride + Fluoride + Nitrate + Sulfate

Bicarbonate + Carbonate

Magnesium

Calcium Chloride + Fluoride + Nitrate

80

60

40

20

80

80

60

40

20

20

20

40

60

80

40

60

80

60

40

20

20

80

60

40

20

40

60

80

80

60

40

20

EXTERIOR
Surface-Water Characteristics 93

Concentrations of dissolved solids for most sites 

representative of the artesian spring setting are higher 

than for the limestone headwater and crystalline core 

sites (fig. 56). The representative artesian spring sites 

generally have calcium sulfate water types (figs. 58 

and 59), resulting from increased sulfate concentrations. Most water discharged by artesian springs probably originates primarily from the Madison and/or 

Minnelusa aquifers (Naus and others, 2001); however, 

high sulfate concentrations probably result primarily 

from rock/water interactions in the Minnelusa Formation. Other potential sulfate sources may be in contact 

with shale confining units such as the Spearfish Formation. Several artesian springs with low sulfate concentrations are located upgradient from the anhydrite 

transition zone in the Minnelusa aquifer (fig. 35).

Exterior sites generally have sodium calcium 

magnesium sulfate type waters (figs. 58 and 59), with 

high concentrations of dissolved solids (fig. 56), relative to other sites. Although no stream reaches within 

the exterior setting are classified for domestic water 

supply, most samples for exterior sites have dissolved 

solids concentrations that exceed the 30-day average 

and maximum criteria of 1,000 and 1,750 mg/L, 

respectively (table 9). The criteria for wildlife propagation and stock watering also are exceeded for many 

samples.

Median concentrations of sodium, chloride, 

magnesium, and sulfate are much higher for the exterior sites than for sites representative of the other settings (fig. 59). Specific conductance values for many of 

the exterior samples (fig. 56) exceed the criteria for 

irrigation waters (table 10); however, no samples for 

this setting exceed the criterion for sodium-adsorption 

ratio (Williamson and Carter, 2001). The highest chloride concentrations occur in the Cheyenne River at 

Edgemont, where numerous samples exceed the SMCL 

of 250 mg/L. Figure 60 presents a spatial distribution 

of median sulfate concentrations for the study area, 

including numerous sites in addition to those that are 

representative of the hydrogeologic settings. The 

highest sulfate concentrations are for sites within the 

exterior hydrogeologic setting, which results from contact with outcrops of Cretaceous shales within this area 

(figs. 9 and 14). Several streams with large influence 

from artesian springs also have relatively high sulfate 

concentrations.

Figure 59. Stiff diagrams (Stiff, 1951) showing median concentrations by hydrogeologic setting 

(from Williamson and Carter, 2001).

Bicarbonate

Sulfate

Calcium

Magnesium

Bicarbonate

Sulfate

Calcium

Magnesium

50 0 50

MILLIEQUIVALENTS, PER LITER

MILLIEQUIVALENTS, PER LITER

MILLIEQUIVALENTS, PER LITER

MILLIEQUIVALENTS, PER LITER

50 0 50

LIMESTONE HEADWATER

EXTERIOR

Chloride + Fluoride

Bicarbonate

Sulfate

Sodium + Potassium Chloride + Fluoride Sodium + Potassium

Sodium + Potassium Chloride + Fluoride Sodium + Potassium Chloride + Fluoride

Calcium

Magnesium

Bicarbonate

Sulfate

Calcium

Magnesium

50 0 50

50 0 50

CRYSTALLINE CORE

ARTESIAN SPRING
94 Hydrology of the Black Hills Area, South Dakota

Figure 60. Spatial distribution of median sulfate concentrations in surface water (from Williamson and Carter, 2001).

N. Fork Rapid Cr

Belle Fourche

Reservoir

FOURCHE

Victoria

Spring

Rhoads Fork

Coolidge

Highland

Angostura

Reservoir

Castl e Cr

N. Fork Castle Cr

Hell

Canyon

Canyon

Red

Bear

Gulch

Creek

Crow

Sheridan

Lake

Hot Brook Canyon

Cox

Lake

Deerfield

Reservoir

Pactola

Reservoir

Indian Cr

Horse

Creek

Owl

BELLE

Creek

RIVER

REDWATER

R I VER

Creek

Cr

Little Spearfish

Spearfish

Creek

Spearfish

Whitewood

Creek

Creek

Bear

Butte

Elk

Creek

Creek

Boxelder

Rapid

Rapid

Creek

Creek

Creek

Spring

Creek

French

Creek

Creek

Creek

Grace

Creek

Creek

Creek

S. Fork

Gillette

S. Fork Rapid Cr

Battle

French

Beaver

Beaver

Creek

Creek

Creek

Creek

Creek

Fall R

Hat

Creek

Creek

Horsehead

CHEYENNE

RIVER

Cottonwood

Hay Creek

Bottom

False

Creek

Spokane

Lame

Johnny

Higgins

Beaver

Cr

Whitetail

Cr

Cr

Cr Cr

Gulch

Annie

Squaw

Deadwood

Creek

Alkali

Iron Cr

Elk

Little

Creek

Castle

Castle

Creek

Creek

Bear Gulch

Cr Strawberry

Boles

Canyon

Canyon

Redbird Canyon

Cold

Beaver

Spring

C s

reek

Creek

Whitewood

Spearfish

Saint

Onge

DEADWOOD

Lead

BELLE FOURCHE

Newell

STURGIS

Blackhawk

Piedmont

Tilford

Box Elder 

Hill City

Hermosa

CUSTER

HOT SPRINGS

Edgemont

Minnekahta

Tinton Central

City

Roubaix

Nemo

Vale

Nisland

Hayward

Keystone

Rochford

Pringle

Fairburn

Buffalo Gap

Dewey

Cascade

Springs

Igloo

Provo

Oral

Rockerville

RAPID CITY

LIMESTONE PLATEAU

 Wind Cave

National Park

Jewel Cave

National

Monument

Mt. Rushmore

National

Memorial

CUSTER

STATE

PARK

Wind

Cave

Harney

Peak

x

Ellsworth

Air Force

Base

BUTTE CO

LAWRENCE CO MEADE CO

PENNINGTON CO

CUSTER CO

FALL RIVER CO

WYOMING

SOUTH DAKOTA

0 10 20

0 10 20 MILES

KILOMETERS

EXPLANATION

MEDIAN SULFATE CONCEN-

 TRATION, IN MILLIGRAMS

 PER LITER 

Less than 331

331 to 660

661 to 990

991 to 1,320

Greater than 1,320

104o 45' 103o

30'

15' 103o

30'

44o45'

15'

44o

45'

30'

43o

15'

OUTCROP OF MADISON LIME-

 STONE (from Strobel and

 others, 1999)

HYDROGEOLOGIC SETTINGS

Limestone headwater

OUTCROP OF MINNELUSA

 FORMATION (from Strobel

 and others, 1999)

Crystalline core

Loss zone and artesian

 spring--Outer extent approxi-

 mates the outer extent of the

 Black Hills area

Exterior

Base modified from U.S. Geological Survey digital data,

1:100,000, 1977, 1979, 1981, 1983, 1985

Rapid City, Office of City Engineer map, 1:18,000, 1996

Universal Transverse Mercator projection, zone 13
Surface-Water Characteristics 95

Anthropogenic Effects

Various human activities, including agriculture, 

mining, and urban/suburban development, have potential to influence the water quality of streams within the 

study area. In many cases, anthropogenic influences on 

water quality cannot necessarily be distinguished from 

naturally occurring influences. Water-quality sampling 

for the Black Hills Hydrology Study was performed 

primarily for the purpose of identifying baseline waterquality conditions; extensive investigations to evaluate 

effects of anthropogenic influences were not performed 

as part of the study. Much of the information summarized in this section was obtained from results of sitespecific studies by previous investigators. A detailed 

summary of previous investigations is provided in 

Williamson and Carter (2001).

Extensive studies of potential effects of irrigation drainage were performed under the National Irrigation Water Quality Program (NIWQP) during the late 

1980’s by Greene and others (1990) for the Angostura 

Reclamation Unit and by Roddy and others (1991) for 

the Belle Fourche Reclamation Project. Concentrations 

of pesticides in water, bottom sediment, and biota were 

less than laboratory reporting limits for most samples 

collected by these investigators. Results of follow-up 

sampling efforts were presented by Sando and others 

(2001), who concluded that for both irrigation projects, 

available data were insufficient to confidently quantify 

potential increases in dissolved solids loading resulting 

from irrigation operations.

Selenium, which can be concentrated by irrigation operations, was a special concern of NIWQP 

because of toxicity and prevalence in irrigation areas in 

the western United States. Selenium is abundant in the 

Cretaceous shales surrounding the Black Hills area 

(figs. 9 and 14), which is reflected in the maximum 

selenium concentrations measured at selected sites 

within the study area (fig. 61). Selenium concentrations below the laboratory reporting limit of 1 μg/L 

have been reported for numerous additional sites (not 

shown in fig. 61), most of which are located within the 

limestone headwater, crystalline core, or artesian 

spring settings. Sando and others (2001) concluded that 

selenium routinely occurs in concentrations that could 

be problematic, both upstream and downstream from 

both irrigation projects. Increased selenium loading 

resulting from irrigation operations was not discernible 

for the Angostura Reclamation Unit; however, 

increased loading probably occurs from return flows in 

Horse Creek, within the Belle Fourche Reclamation 

Project.

Effects of mining activity on water quality can be 

difficult to quantify because natural influences in mineralized areas may have similar effects on water 

quality. Mining activities generally have been most 

extensive in the northern Black Hills, primarily in the 

vicinity of Tertiary intrusive units (fig. 14) where the 

largest deposits of gold ores tend to be located.

One potential effect of mining is acid-mine 

drainage, which can result from weathering and oxidation of sulfide minerals that occur in some locations. 

Torve (1991) examined pH conditions and metals concentrations near abandoned mines along Deadwood 

Creek and False Bottom Creek. Measured pH values 

for sites (fig. 62) upstream, immediately downstream, 

and farther downstream of the mines are presented in 

figure 63. The pH values are depressed in the immediate vicinity of the mines, but increase farther downstream as a result of the buffering effect of carbonate 

minerals. Similar areas of low pH also exist in naturally 

occurring bog-iron areas, which can be found in various locations in the Black Hills area (Luza, 1969; 

Rice, 1970).

Low pH conditions can cause increased solubility of various metals, which can be abundant in 

mineralized areas where mining has occurred. Torve 

(1991) documented elevated concentrations of dissolved cadmium, copper, and zinc that approached or 

exceeded aquatic-life criteria near mines along Deadwood Creek and False Bottom Creek. Decreased concentrations of dissolved metals were documented 

farther downstream, where pH levels increased. 

Approximately 900 abandoned or inactive mines exist 

throughout the Black Hills area (South Dakota Department of Environment and Natural Resources, 2001b); 

similar pH and trace-metal conditions occur at a limited 

number of these locations (Rahn and others, 1996).

Acid-mine drainage has been a problem at the 

Gilt Edge mine (a large, open-pit, heap-leach-recovery 

gold mine that was operated during 1986-98), which 

was listed as a Superfund site by USEPA in 2000 

(South Dakota Department of Environment and 

Natural Resources, 2001b). The mine area is drained by 

Strawberry Creek, which is a tributary to Bear Butte 

Creek. Copper concentrations have frequently 

exceeded aquatic standards in Bear Butte Creek 

(fig. 64). In addition, dissolved solids concentrations 

have increased since 1994 in Bear Butte Creek downstream of the confluence with Strawberry Creek, 

primarily from increases in sodium and sulfate concentrations (Williamson and Carter, 2001).
96 Hydrology of the Black Hills Area, South Dakota

Figure 61. Spatial distribution of maximum selenium concentrations in surface water (from Williamson and Carter, 2001).

N. Fork Rapid Cr

Belle Fourche

Reservoir

FOURCHE

Victoria

Spring

Rhoads Fork

Coolidge

Highland

Angostura

Reservoir

Castl e Cr

N. Fork Castle Cr

Hell

Canyon

Canyon

Red

Bear

Gulch

Creek

Crow

Sheridan

Lake

Hot Brook Canyon

Cox

Lake

Deerfield

Reservoir

Pactola

Reservoir

Indian Cr

Horse

Creek

Owl

BELLE

Creek

RIVER

REDWATER

R I VER

Creek

Cr

Little Spearfish

Spearfish

Creek

Spearfish

Whitewood

Creek

Creek

Bear

Butte

Elk

Elk

Creek

Creek

Creek

Boxelder

Rapid

Rapid

Creek

Creek

Creek

Spring

Creek

French

Creek

Creek

Creek

Grace

Creek

Creek

Creek

S. Fork

Gillette

S. Fork Rapid Cr

Battle

French

Beaver

Beaver

Creek

Creek

Creek

Creek

Creek

Fall R

Hat

Creek

Creek

Horsehead

CHEYENNE

RIVER

Cottonwood

Hay Creek

Bottom

False

Creek

Spokane

Lame

Johnny

Higgins

Beaver

Cr

Whitetail

Cr

Cr

Cr Cr

Gulch

Annie

Squaw

Deadwood

Creek

Alkali

Iron Cr

Elk

Little

Creek

Castle

Castle

Creek

Creek

Bear Gulch

Cr Strawberry

Boles

Canyon

Canyon

Redbird Canyon

Cold

Beaver

Spring

C s

reek

Creek

Whitewood

Spearfish

Saint

Onge

DEADWOOD

Lead

BELLE FOURCHE

Newell

STURGIS

Blackhawk

Piedmont

Tilford

Box Elder 

Hill City

Hermosa

CUSTER

HOT SPRINGS

Edgemont

Minnekahta

Tinton Central

City

Roubaix

Nemo

Vale

Nisland

Hayward

Keystone

Rochford

Pringle

Fairburn

Buffalo Gap

Dewey

Cascade

Springs

Igloo

Provo

Oral

Rockerville

RAPID CITY

LIMESTONE PLATEAU

 Wind Cave

National Park

Jewel Cave

National

Monument

Mt. Rushmore

National

Memorial

CUSTER

STATE

PARK

Wind

Cave

Harney

Peak

x

Ellsworth

Air Force

Base

BUTTE CO

LAWRENCE CO MEADE CO

PENNINGTON CO

CUSTER CO

FALL RIVER CO

WYOMING

SOUTH DAKOTA

0 10 20

0 10 20 MILES

KILOMETERS

EXPLANATION

MAXIMUM SELENIUM CONCEN-

 TRATION, IN MICROGRAMS

 PER LITER 

Less than 6

6 to 20

21 to 35

36 to 50

51 to 70

104o 45' 103o

30'

15' 103o

30'

44o45'

15'

44o

45'

30'

43o

15'

OUTCROP OF MADISON LIME-

 STONE (from Strobel and

 others, 1999)

OUTCROP OF MINNELUSA

 FORMATION (from Strobel

 and others, 1999)

Exterior

HYDROGEOLOGIC SETTINGS

Limestone headwater

Crystalline core

Loss zone and artesian

 spring--Outer extent approxi-

 mates the outer extent of the

 Black Hills area

Base modified from U.S. Geological Survey digital data,

1:100,000, 1977, 1979, 1981, 1983, 1985

Rapid City, Office of City Engineer map, 1:18,000, 1996

Universal Transverse Mercator projection, zone 13
Surface-Water Characteristics 97

Figure 62. Locations of selected water-quality sampling sites used for analysis of anthropogenic effects in 

(A) Lawrence County and (B) Rapid Creek Basin.

PENNINGTON COUNTY

CUSTER COUNTY

LAWRENCE COUNTY

WYOMING

MEADE COUNTY

SOUTH DAKOTA

Ellsworth

Air Force Base

RAPID

CITY

Creston

Big Bend

Silver City

Rochford

Deerfield

Crooks

Tower

Caputa

Farmingdale

104o

44o

15'

44o

103o

30' 103o

104o

50' 103o

40'

44o

30'

20'

44o

10'

Rapid

Creek

Deerfield Dam

and Reservoir

Pactola Dam

and Reservoir

Castle

Creek

Rhoads Fk

South

Fork

Victoria C r

CHEYENNE RIVER

North Fork

Rapid Creek

Canyon

Lake

Spearfish

Spearfish

Creek

Creek

False Creek Creek

Creek

Creek

Bottom

Whitewood

Whitetail

Little

Iron Creek

REDWATER RIVER

Robison Gulch

Squaw Creek Annie Creek

Bear

Gulch

Beaver

Creek

Crow

Creek

Bear

Butte

Boxelder

Creek

North Fork

Rapid

Creek

Cr

Deadwood

Elk

Cr

East

Cr Spearfish

Strawberry

Spearfish

Whitewood

DEADWOOD

Lead

Central

City

Nemo

Roubaix

06409000

06409000

06412500

06410500 06414000

06418900

06421500

06411500

06409000

06412500

06410500 06414000

06418900

06421500

06411500

0 10 20

0 10 20 KILOMETERS

MILES

EXPLANATION

RAPID CREEK BASIN BOUNDARY

SURFACE-WATER SAMPLING SITE--

 Number is station identification number

Base modified from U.S. Geological Survey

1:500,000 Hydrologic Unit Map, 1978

B

A

EXPLANATION

WATER-QUALITY AND BED-SEDIMENT

 SAMPLING SITE--Number is station

 identification number

06432172

06432172

442213103443900

442125103483000 442131103482000

442252103493800

442246103490300

442250103485700

06432172

442213103443900

442125103483000 442131103482000

442252103493800

442246103490300

442250103485700

Base from U.S. Geological Survey digital line graph, 1:100,000:

Belle Fourche, 1983; Rapid City, 1977

Universal Transverse Mercator projection, zone 13

North American Horizontal Datum 1927

1 2 3 4 5 6 MILES

0 1 2 3 4 5 6 KILOMETERS

0

SOUTH DAKOTA

Black Hills

study area

Rapid Creek

Basin

Lawrence

County
98 Hydrology of the Black Hills Area, South Dakota

Figure 63. Downstream progression of pH for selected streams influenced by acid-mine drainage (from

Williamson and Carter, 2001).

Upstream from mining Downstream from mining Immediately downstream

from mining

3.5

8.5

4.0

4.5

5.0

5.5

6.0

6.5

7.0

7.5

8.0

pH, IN STANDARD UNITS

EXPLANATION

FALSE BOTTOM CREEK

DEADWOOD CREEK

Southeast False Bottom

Creek near Lead

442250103485700

False Bottom Creek above

Columbia Mine near Lead

442251103493800 

False Bottom Creek 

near Central City

06432172

South Deadwood Creek above

Hidden Treasure Mine near Lead

442125103483000

Deadwood Creek below Hidden

Treasure Mine near Lead

442131103482000 

Deadwood Creek below Broken

Boot Mine at Deadwood

442213103443900
Surface-Water Characteristics 99

Figure 64. Comparison of dissolved copper concentrations to hardness-dependent chronic and acute aquatic-life 

criteria for Bear Butte Creek near Deadwood (06437020) (from Williamson and Carter, 2001).

1988 1989 1990 1991 1992 1993 1994

0

35

5

10

15

20

25

30

CONCENTRATION, IN MILLIGRAMS PER LITER

CALENDAR YEAR

EXPLANATION

HARDNESS-DEPENDENT CHRONIC AQUATIC-LIFE CRITERIA

HARDNESS-DEPENDENT ACUTE AQUATIC-LIFE CRITERIA

DISSOLVED COPPER CONCENTRATION
100 Hydrology of the Black Hills Area, South Dakota

Acid-mine drainage from the Richmond Hill 

Mine resulted in depressed pH levels in headwater 

reaches of Squaw Creek (Durkin, 1996). This condition 

resulted in a need for substantial reclamation efforts in 

closing the mine, which consisted of capping large 

deposits of sulfide minerals to prevent exposure to air 

and water.

The spatial distribution of maximum arsenic 

concentrations for the study area is shown in figure 65. 

None of the samples have exceeded the aquatic-life criteria (table 9); however, concentrations exceeding the 

revised MCL of 10 μg/L (table 4) have been measured 

at seven sites. One concentration exceeding 50 μg/L 

has been measured. Concentrations below the laboratory reporting limit of 1 μg/L have been reported for 

numerous additional sites (not shown in fig. 65). 

Arsenic commonly is associated with gold ores, with 

most of the elevated concentrations occurring within 

the crystalline core setting in locations where mining 

activities have occurred. Arsenic also is relatively 

abundant in the Cretaceous shales surrounding the 

Black Hills area, with concentrations above 5 μg/L 

measured at upstream locations on the Cheyenne and 

Belle Fourche Rivers.

Potential effects of mining operations on arsenic 

concentrations generally cannot be quantified because 

background samples (prior to mining activities) are not 

available. Elevated arsenic concentrations in Whitewood Creek and downstream reaches of the Belle 

Fourche River have been attributed to long-term discharge of mine tailings, which resulted in designation 

of an 18-mi reach as a Superfund site by USEPA in 

1983 (Goddard, 1989). Other constituents of concern 

along Whitewood Creek include cadmium, copper, 

cyanide, iron, manganese, mercury, and silver. The 

largest concentrations of dissolved arsenic typically 

occur during storm-flow recessions and result from 

seepage from tailings deposits in the adjacent flood 

plain. Concentrations of total arsenic exceeding 

100 μg/L are common during storm flows when sediments are mobilized.

A variety of factors influencing the solubility of 

arsenic have been identified by previous investigators. 

Arsenic is most soluble within a pH range of 8.1 to 8.6; 

however, adsorption/desorption processes also can 

affect the mobility of arsenic (Fuller and Davis, 1989; 

Fuller and others, 1993). The abundance of calcite 

and ferrihydrite in bed sediments was identified by 

Williamson and Hayes (2000) as important factors in 

controlling adsorption/desorption of arsenic. Solubility 

of arsenic is increased by abundance of calcite because 

of associated increases in pH. Solubility of arsenic is 

reduced by abundance of ferrihydrite, which provides 

iron surfaces for adsorption of arsenic. The highest 

concentrations of dissolved arsenic typically occur in 

streams with limited quantities of ferrihydrite in bed 

sediments. Photosynthesis and respiration by aquatic 

vegetation within a stream can cause diurnal changes in 

pH, resulting in fluctuations in arsenic concentrations 

(Fuller and Davis, 1989).

Arsenic concentrations in Annie Creek that consistently approached the former MCL of 50 μg/L 

resulted in USEPA designation of a 5-acre site on the 

National Priorities List (Driscoll and Hayes, 1995). A 

failed tailings impoundment from an abandoned mine 

had resulted in large deposits of arsenic-rich tailings 

along the stream channel. Natural geology and the 

Annie Creek Mine, which occupies much of the Annie 

Creek drainage basin, also may contribute to elevated 

arsenic concentrations in Annie Creek. An important 

influence is small concentrations of ferrihydrite in bed 

sediments (Williamson and Hayes, 2000), which limits 

adsorption/coprecipitation on ferrihydrite and contributes to high concentrations of dissolved arsenic.

Elevated concentrations of nitrite plus nitrate in 

Annie Creek, with two samples exceeding the MCL of 

10 μg/L in 1995 and 1996, were noted by Williamson 

and Carter (2001). The concentrations probably result 

from the breakdown of blasting agents (ammonium 

nitrate mixed with diesel fuel) and cyanide, which is 

used in the heap-leach extraction process. Two denitrification facilities were installed within the Annie Creek 

Basin in 1997 and have been effective in reducing 

nitrite plus nitrate concentrations (South Dakota 

Department of Environment and Natural Resources, 

1998).

Elevated nitrite plus nitrate concentrations also 

can result from various other influences including fertilizers, animal and human waste, and natural processes 

that occur within stream riparian systems. Nitrite plus 

nitrate concentrations for sites representative of hydrogeologic settings are shown in figure 66. In this figure, 

Annie Creek is separated from other crystalline core 

sites because of the substantial influence from mining 

operations, as previously discussed. Concentrations for 

most sites representative of individual hydrogeologic 

settings are below 1 μg/L, which probably is indicative 

of conditions with little human influence. Numerous 

samples for sites that are not representative of individual hydrogeologic settings are included in an “other 

sites” category. Most of the elevated concentrations for 

this category were collected prior to 1980 from Horse 

Creek near Vale (Williamson and Carter, 2001), which 

is influenced by irrigation return flows.
Surface-Water Characteristics 101

Figure 65. Spatial distribution of maximum arsenic concentrations in surface water (modified from Williamson and 

Carter, 2001).

N. Fork Rapid Cr

Belle Fourche

Reservoir

FOURCHE

Victoria

Spring

Rhoads Fork

Coolidge

Highland

Angostura

Reservoir

Castl e Cr

N. Fork Castle Cr

Hell

Canyon

Canyon

Red

Bear

Gulch

Creek

Crow

Sheridan

Lake

Hot Brook Canyon

Cox

Lake

Deerfield

Reservoir

Pactola

Reservoir

Indian Cr

Horse

Creek

Owl

BELLE

Creek

RIVER

REDWATER

R I VER

Creek

Cr

Little Spearfish

Spearfish

Creek

Spearfish

Whitewood

Creek

Creek

Bear

Butte

Elk

Elk

Creek

Creek

Creek

Boxelder

Rapid

Rapid

Creek

Creek

Creek

Spring

Creek

French

Creek

Creek

Creek

Grace

Creek

Creek

Creek

S. Fork

Gillette

S. Fork Rapid Cr

Battle

French

Beaver

Beaver

Creek

Creek

Creek

Creek

Creek

Fall R

Hat

Creek

Creek

Horsehead

CHEYENNE

RIVER

Cottonwood

Hay Creek

Bottom

False

Creek

Spokane

Lame

Johnny

Higgins

Beaver

Cr

Whitetail

Cr

Cr

Cr Cr

Gulch

Annie

Squaw

Deadwood

Creek

Alkali

Iron Cr

Elk

Little

Creek

Castle

Castle

Creek

Creek

Bear Gulch

Cr Strawberry

Boles

Canyon

Canyon

Redbird Canyon

Cold

Beaver

Spring

C s

reek

Creek

Whitewood

Spearfish

Saint

Onge

DEADWOOD

Lead

BELLE FOURCHE

Newell

STURGIS

Blackhawk

Piedmont

Tilford

Box Elder 

Hill City

Hermosa

CUSTER

HOT SPRINGS

Edgemont

Minnekahta

Tinton Central

City

Roubaix

Nemo

Vale

Nisland

Hayward

Keystone

Rochford

Pringle

Fairburn

Buffalo Gap

Dewey

Cascade

Springs

Igloo

Provo

Oral

Rockerville

RAPID CITY

LIMESTONE PLATEAU

 Wind Cave

National Park

Jewel Cave

National

Monument

Mt. Rushmore

National

Memorial

CUSTER

STATE

PARK

Wind

Cave

Harney

Peak

x

Ellsworth

Air Force

Base

BUTTE CO

LAWRENCE CO MEADE CO

PENNINGTON CO

CUSTER CO

FALL RIVER CO

WYOMING

SOUTH DAKOTA

0 10 20

0 10 20 MILES

KILOMETERS

EXPLANATION

MAXIMUM ARSENIC CONCEN-

 TRATION, IN MICROGRAMS

 PER LITER 

Less than 6

6 to 10

11 to 35

36 to 50

51 to 68

104o 45' 103o

30'

15' 103o

30'

44o

45'

15'

44o

45'

30'

43o

15'

OUTCROP OF MADISON LIME-

 STONE (from Strobel and

 others, 1999)

HYDROGEOLOGIC SETTINGS

Limestone headwater

OUTCROP OF MINNELUSA

 FORMATION (from Strobel

 and others, 1999)

Crystalline core

Loss zone and artesian

 spring--Outer extent approxi-

 mates the outer extent of the

 Black Hills area

Exterior

Base modified from U.S. Geological Survey digital data,

1:100,000, 1977, 1979, 1981, 1983, 1985

Rapid City, Office of City Engineer map, 1:18,000, 1996

Universal Transverse Mercator projection, zone 13
102 Hydrology of the Black Hills Area, South Dakota

Figure 66. Boxplots of concentrations of dissolved nitrite plus nitrate by hydrogeologic setting, with Annie Creek 

separated from other crystalline core sites. DISSOLVED NITRITE PLUS NITRATE CONCENTRATION, IN MILLIGRAMS PER LITER

106/1 80/6 25/0 7/0 56/1 1197/43

Limestone

headwater

sites

Crystalline core sites

without

Annie Creek

Annie Creek Artesian

spring sites

Exterior

sites

Other

sites

HYDROGEOLOGIC SETTING

0.001

100

0.002

0.005

0.01

0.02

0.05

0.1

0.2

0.5

1

2

5

10

20

50

EXPLANATION

Number of samples/Number of samples with

 concentrations below the laboratory reporting limit

106/1 Highest reporting limit

Maximum Contaminant Level

 (U.S. Environmental Protection

 Agency, 1994a)

25th percentile

Median

75th percentile

Data value less than or equal to 1.5 times the

 interquartile range outside the quartile

Outlier data value less than or equal to 3 and more

 than 1.5 times the interquartile range outside the

 quartile
Hydrologic Budgets 103

Nitrite plus nitrate concentrations for selected 

sites within the Rapid Creek Basin (fig. 62) are presented in figure 67. Concentrations for the farthest site 

upstream (06409000, Castle Creek above Deerfield) 

generally are slightly higher than for the next two sites 

downstream. One possible nitrogen source, based on 

land-use activities, is cattle grazing upstream from the 

farthest site upstream. Rapid Creek at Rapid City 

(06414000) shows minor influences of nitrite plus 

nitrate from various possible urban sources. Concentrations at Rapid Creek near Farmingdale (06421500) 

increase markedly, reflecting various possible influences including non-point urban/suburban sources, 

effluent discharge from the Rapid City municipal 

wastewater treatment plant, and various possible 

influences from agricultural activities.

Numerous constituents in addition to nitrite plus 

nitrate can influence water quality in urban environments. Williamson and others (1996) documented 

increased concentrations of various trace metals contributed to Rapid Creek by the Rapid City municipal 

wastewater treatment plant. Goddard and others (1989) 

summarized data collected during a USEPA National 

Urban Runoff Program study in the Rapid City area. In 

an interpretation of this data set, Harms and others 

(1983) documented increases in numerous constituents 

in Rapid Creek associated with urban runoff.

Additional Factors Relative to In-Stream Standards

Beneficial uses for various stream reaches can be 

influenced by several other factors in addition to those 

that have been previously discussed. Detailed discussions of low pH conditions associated with acid-mine 

drainage were presented previously. Low pH values 

below the desirable range (table 9) also can occur naturally, especially in areas with bog-iron deposits (Luza, 

1969). Occurrences generally are in limited stream 

reaches within the crystalline core setting. Occasional 

occurrences of pH values exceeding the desirable range 

have been noted in the limestone headwater and crystalline core settings (Williamson and Carter, 2001).

Beneficial uses for some stream reaches also can 

be limited by temperature and dissolved oxygen concentrations. In-stream temperatures exceeding beneficial-use criteria for fisheries (table 9) occasionally 

occur, especially during low-flow conditions. Concentrations of dissolved oxygen below desirable ranges 

also can occur occasionally, especially during low-flow 

conditions and when elevated temperatures reduce 

oxygen solubility. Low concentrations of dissolved 

oxygen associated with urban runoff also have been 

documented (Harms and others, 1983).

Concentrations of suspended solids exceeding 

beneficial-use criteria are relatively common in the 

Black Hills area. The largest (and most frequent) 

exceedances typically occur in the exterior setting, 

where fine-grained particulates associated with clay 

soils are easily mobilized during high-flow conditions. 

High concentrations of suspended solids also typically 

occur during urban runoff events (Harms and others, 

1983).

HYDROLOGIC BUDGETS

The quantification of various hydrologic budget 

components is important for managing and understanding the water resources in the Black Hills area. 

This section contains summaries of hydrologic budgets 

that were developed by previous investigators for 

ground water, surface water, and the combined groundwater/surface-water system. A detailed hydrologic 

budget for the Madison and Minnelusa aquifers in the 

Black Hills of South Dakota and Wyoming for 1987-96 

was presented by Carter, Driscoll, Hamade, and Jarrell 

(2001). Detailed hydrologic data sets were available for 

this period, during which changes in ground-water 

storage were considered negligible. Basic hydrologic 

budgets for the Black Hills of South Dakota for 

1950-98 were presented by Driscoll and Carter (2001) 

for: (1) the Madison and Minnelusa aquifers; (2) other 

bedrock aquifers; (3) surface water; and (4) the combined ground-water/surface-water system. This timeframe includes an extended period of particularly dry 

climatic conditions that occurred during the 1950’s 

(fig. 8) and the particularly wet conditions that 

occurred during the middle to late 1990’s.

All hydrologic budgets were developed from the 

following basic continuity equation, which states that 

for any designated volume:

(2)

where:

ΣInflows = sum of inflows;

ΣOutflows = sum of outflows; and

∆Storage = change in storage.

Thus, a positive ∆Storage results when inflows exceed 

outflows. 

ΣInflows – ΣOutflows = ∆Storage
104 Hydrology of the Black Hills Area, South Dakota

Figure 67. Boxplots of concentrations of dissolved nitrite plus nitrate within the Rapid Creek Basin.

99/0 133/1 25/4 144/0 35/0

06409000

Castle Creek

above

Deerfield Reservoir

06411500

Rapid Creek

below

Pactola Dam

06412500

Rapid Creek

above

Canyon Lake

06414000

Rapid Creek

at

Rapid City

06421500

Rapid Creek

near

Farmingdale

0.001

100

0.002

0.005

0.01

0.02

0.05

0.1

0.2

0.5

1

2

5

10

20

50

DISSOLVED NITRITE PLUS NITRATE CONCENTRATION,

IN MILLIGRAMS PER LITER

EXPLANATION

Number of samples/Number of samples with concentrations

 below the laboratory reporting limit

99/0

Highest reporting limit

25th percentile

Median

75th percentile

Data value less than or equal to 1.5 times the interquartile

 range outside the quartile

Outlier data value less than or equal to 3 and more than 1.5

 times the interquartile range outside the quartile

Outlier data value more than 3 times the interquartile range 

 outside the quartile

Maximum Contaminant Level (U.S. Environmental

 Protection Agency, 1994a)
Hydrologic Budgets 105

Methods for Estimating Basin Yield and 

Recharge

Total yield, which is considered to be the sum of 

runoff plus recharge, was estimated over selected areas 

using the “yield-efficiency algorithm” discussed in a 

previous section. Estimates of precipitation, total yield, 

and evapotranspiration for the entire study area are presented in table 11. For 1950-98, precipitation averaged 

18.98 inches or about 5.2 million acre-ft/yr. This is 

equivalent to an average flow rate of about 7,240 ft3/s. 

Of this amount, total yield is estimated as about 

440,600 acre-ft/yr (about 608 ft3/s), which is equivalent to about 1.59 inches over the study area. Thus, 

evapotranspiration is estimated as 17.39 in/yr, which 

accounts for about 92 percent of annual precipitation.

Total yield was apportioned between precipitation recharge and runoff on the basis of recharge factors 

for each aquifer (table 12). With the exception of localized aquifers in the crystalline core, as discussed later, 

recharge was estimated by multiplying the total yield 

by the recharge factor, which is the fraction of total 

yield estimated to be recharge for a particular unit. The 

remainder of total yield (if any) was assumed to contribute to runoff from the outcrop area. Of the total 

average annual precipitation in the study area 

(table 11), runoff accounts for about 4.9 percent 

(352 ft3/s), and precipitation recharge accounts for 

about 3.5 percent (256 ft3/s). Thus, only a small 

fraction of the water originating from precipitation 

recharges the aquifers by infiltrating in outcrop areas.

Table 11. Estimates of average precipitation, precipitation recharge, runoff, total yield, and evapotranspiration for the study 

area, water years 1950-98

[Modified from Driscoll and Carter (2000)]

Units Precipitation Precipitation 

recharge Runoff

Total yield

(Precipitation 

recharge + runoff)

Evapotranspiration

Acre-feet per year 5,245,400 185,500 255,100 440,600 4,804,800

Cubic feet per second 7,240.4 256 352 608.2 6,632.2

Inches per year 18.98 0.67 0.92 1.59 17.39

Table 12. Recharge factors and outcrop areas for bedrock aquifers

[From Driscoll and Carter (2001). --, not applicable]

Aquifer unit Recharge factor1 Outcrop area

(acres)

Localized aquifers in crystalline core area

(Precambrian/Tertiary/Other2)

-- 616,800

Deadwood 0.80 66,200

Madison 1.00 292,600

Minnelusa 1.00 300,000

Minnekahta 1.00 72,100

Inyan Kara .80 219,700

Jurassic-sequence semiconfining unit .40 75,800

Cretaceous-sequence confining unit .05 716,100

1

Fraction of total yield estimated to result in recharge, with remainder (if any) assumed to contribute to runoff. 2Other consists of other units within the crystalline core area, including: (1) isolated outcrops of the Deadwood Formation, Madison Limestone, and Minnelusa Formation, and Minnekahta Limestone above the loss zones; and (2) unconsolidated sedimentary deposits.
106 Hydrology of the Black Hills Area, South Dakota

As previously discussed, direct runoff from outcrops of the Madison Limestone and Minnelusa Formation seldom occurs. Thus, all precipitation on these 

outcrops that is not evapotranspirated was assumed to 

recharge the aquifers; hence, recharge factors for these 

aquifers were assumed to be 1.00. The recharge factor 

for the Minnekahta aquifer also was assumed to be 

1.00, based on similar formation properties between 

the Minnekahta Limestone and Madison Limestone. 

Recharge factors for the Inyan Kara and Deadwood 

aquifers were assumed to be 0.80 because these formations contain more shale layers than the Madison, 

Minnelusa, and Minnekahta Formations. The Sundance aquifer within the Jurassic-sequence semiconfining unit is a productive aquifer, but only constitutes 

about one-half of the outcrop area of the total unit. 

Thus, a recharge efficiency of 0.40 (one-half of 0.80) 

was assumed for the entire Jurassic-sequence semiconfining unit. Likewise, the Newcastle Sandstone contains a productive aquifer within the Cretaceoussequence confining unit; however, the Newcastle 

Sandstone constitutes only a small portion of the total 

unit in outcrop area. Thus, a recharge factor of 0.05 was 

assumed for the entire Cretaceous-sequence confining 

unit.

Recharge does occur to numerous localized aquifers within the crystalline core area, especially where 

extensive fractures and weathered zones are present. 

These aquifers are not considered regional, however, as 

indicated by the fact that wells constructed in Precambrian rocks in western South Dakota outside of the 

Black Hills have not encountered measurable amounts 

of ground water (Rahn, 1985). Thus, regional groundwater flow in the Precambrian rocks was assumed to be 

negligible although some flow may occur in the upper 

weathered zone. Recharge to localized aquifers in the 

crystalline core area was assumed equal to well withdrawals from this unit. Actual recharge to the crystalline core aquifers must be much larger than this 

estimate to accommodate ground-water discharge that 

contributes to base flow of many streams. Recharge 

conditions are highly transient and have large spatial 

variability; thus, quantification was not attempted.

Within the crystalline core area, numerous erosional remnants of sedimentary outcrops occur that are 

“isolated” from regional ground-water flow systems as 

described in a previous section (fig. 14). Precipitation 

recharge was prescribed only for “connected” outcrops 

and was not prescribed for isolated outcrops. Infiltration of precipitation on isolated outcrops was assumed 

to contribute to streamflow, which eventually has 

potential to provide streamflow recharge to the 

Madison and Minnelusa aquifers. Additional methods 

beyond identification of isolated and connected outcrop areas were used in quantifying precipitation 

recharge for the Deadwood aquifer as described by 

Driscoll and Carter (2001). Additional details 

regarding precipitation recharge are discussed in the 

following sections.

Ground-Water Budgets

Ground-water budgets were developed for five 

major, sedimentary bedrock aquifers within the study 

area (Deadwood, Madison, Minnelusa, Minnekahta, 

and Inyan Kara aquifers) and for additional minor aquifers within the Jurassic-sequence semiconfining unit 

and Cretaceous-sequence confining unit. A budget also 

was developed for localized aquifers within the crystalline core area, which is dominated by Precambrian 

igneous and metamorphic rocks, but also includes 

Tertiary igneous rocks, erosional remnants of various 

sedimentary rocks, and minor, unconsolidated sedimentary deposits. These localized aquifers are subsequently referred to as the crystalline core aquifers. A 

combined budget was developed for the Madison and 

Minnelusa aquifers because most of the budget components cannot be quantified individually for these two 

aquifers; this budget is presented prior to budgets for 

the other bedrock aquifers.

Long-term budgets were developed for the 

period 1950-98, during which changes in ground-water 

storage were assumed to be negligible. Various components in equation 1 for ground-water budgets are schematically illustrated in figure 16 for the Madison 

aquifer. Inflows may include recharge, vertical leakage 

from adjacent aquifers, and lateral ground-water 

inflows across the study area boundary. Recharge 

occurs at or near land surface and includes infiltration 

of precipitation on outcrops of the bedrock units and 

streamflow recharge, which occurs where streams 

cross the outcrops. Streamflow recharge was considered an inflow component only for the Madison and 

Minnelusa aquifers. Although the Minnekahta aquifer 

also receives limited recharge from streamflow losses, 

this recharge probably is very small relative to streamflow recharge to the Madison and Minnelusa aquifers 

and could not be quantified. 

Outflows include springflow, well withdrawals, 

vertical leakage to adjacent aquifers, and lateral 
Hydrologic Budgets 107

ground-water outflow across the study area boundary. 

Springflow includes headwater springs and artesian 

springs. Headwater springs, which generally occur near 

the base of the Madison Limestone in the Limestone 

Plateau area, were considered an outflow component 

for only the Deadwood, Madison, and Minnelusa aquifers. Artesian springs, which constitute a form of 

leakage but are treated as a separate component 

because of magnitude and measurability, were considered an outflow component for only the Madison and 

Minnelusa aquifers.

Vertical leakage to and from adjacent aquifers, 

which is difficult to quantify and cannot be distinguished from lateral ground-water inflows or outflows 

across the study area boundaries, probably is small relative to other budget components in most cases. Thus, 

for budget purposes, leakage was included with 

ground-water inflows and outflows. Assuming that 

∆Storage is equal to zero, the sum of the inflows is 

equal to the sum of the outflows, and the hydrologic 

budget equation can be rewritten as:

(3)

The terms on the right side of equation 3 generally can be quantified more accurately than the terms 

on the left. Therefore, net ground-water flow (outflow 

minus inflow) from the study area can be calculated as 

the residual, given estimates for the other budget components.

Budgets for Madison and Minnelusa Aquifers

Recent investigations have provided extensive 

information regarding various budget components for 

the Madison and Minnelusa aquifers, which are presented in table 13. Many of the budget components 

were based on hydrologic measurements with relatively short periods of record. Precipitation records 

indicate that prolonged drought conditions occurred 

prior to many available hydrologic records. Thus, 

Carter, Driscoll, and Hamade (2001) estimated 

recharge for the Madison and Minnelusa aquifer for 

1931-98 (fig. 68) to address particularly dry conditions 

that occurred during the 1930’s and 1950’s. Estimates 

of streamflow recharge, precipitation recharge, and 

combined recharge from both sources (for the 

expanded area that includes part of Wyoming) are 

shown in figure 68. The 1931-98 averages are smaller 

than the 1950-98 averages (table 13) because of prolonged droughts during the 1930’s and 1950’s. Streamflow recharge is relatively steady; however, precipitation recharge is highly variable, depending on annual 

precipitation amounts.

Ground-wateroutflow Ground-waterinflow –

= Recharge Headwater springflow –

– Artesian springflow Well withdrawals –

Figure 68. Annual recharge to the Madison and Minnelusa aquifers, water years 1931-98, in the Black Hills of South Dakota 

and Wyoming (from Carter, Driscoll, and Hamade, 2001).

1930 1940 1950 1960 1970 1980 1990 2000

WATER YEAR

0

1,000

200

400

600

800

RECHARGE,

IN CUBIC FEET PER SECOND

EXPLANATION

STREAMFLOW RECHARGE

PRECIPITATION RECHARGE

COMBINED RECHARGE

AVERAGE STREAMFLOW RECHARGE

 (1931-98)

AVERAGE PRECIPITATION RECHARGE

 (1931-98)

AVERAGE COMBINED RECHARGE

 (1931-98)
108 Hydrology of the Black Hills Area, South Dakota

Table 13. Estimated annual hydrologic budget components for the Madison and Minnelusa aquifers, water years 1931-98, 

for the Black Hills of South Dakota and Wyoming 

[All estimates in cubic feet per second. --, not determined]

Water year

Recharge1

Headwater 

springflow2

Artesian 

springflow3

Well

withdrawals3

Net

ground-water 

outflow Streamflow Precipitation Total 3

1931 38.17 57.37 95.53 3.6 -- -- --

1932 107.61 293.82 401.44 76.7 -- -- --

1933 98.50 262.78 361.28 63.6 -- -- --

1934 37.38 54.70 92.08 4.5 -- -- --

1935 61.71 137.54 199.25 28.6 -- -- --

1936 30.45 31.08 61.53 1.0 -- -- --

1937 53.55 109.75 163.30 16.4 -- -- --

1938 58.12 125.31 183.44 21.4 -- -- --

1939 58.78 127.53 186.31 24.0 -- -- --

1940 49.57 96.18 145.75 13.5 -- -- --

1941 128.70 365.63 494.34 99.7 -- -- --

1942 100.57 269.84 370.41 65.4 -- -- --

1943 79.75 198.96 278.72 48.5 -- -- --

1944 71.33 170.29 241.62 36.2 -- -- --

1945 125.98 356.35 482.33 102.1 -- -- --

1946 189.51 572.68 762.19 190.8 -- -- --

1947 89.69 232.79 322.47 56.5 -- -- --

1948 79.14 196.87 276.01 45.9 -- -- --

1949 56.72 120.53 177.24 20.1 -- -- --

1950 79.50 178.87 258.36 40.0 -- -- --

1951 76.09 160.75 236.84 30.5 -- -- --

1952 113.52 180.03 293.55 41.7 -- -- --

1953 96.62 184.32 280.94 45.8 -- -- --

1954 66.10 95.61 161.71 16.9 -- -- --

1955 65.04 268.06 333.09 71.0 -- -- --

1956 65.90 134.06 199.96 25.2 -- -- --

1957 117.12 278.05 395.17 70.7 -- -- --

1958 73.20 185.27 258.47 39.8 -- -- --

1959 60.53 140.36 200.89 26.2 -- -- --

1960 59.57 117.59 177.16 26.7 -- -- --

1961 54.97 68.88 123.85 7.0 -- -- --

1962 122.52 513.23 635.75 158.7 -- -- --

1963 103.64 426.54 530.18 128.5 -- -- --

1964 95.48 472.86 568.33 157.9 -- -- --

1965 140.80 525.80 666.60 161.7 -- -- --

1966 98.23 136.11 234.33 21.1 -- -- --

1967 121.00 319.45 440.45 83.3 -- -- --
Hydrologic Budgets 109

1968 82.87 246.91 329.78 62.2 -- -- --

1969 74.24 215.90 290.14 50.6 -- -- --

1970 105.19 293.58 398.77 78.7 -- -- --

1971 123.68 365.41 489.09 101.4 -- -- --

1972 126.93 418.46 545.40 119.9 -- -- --

1973 123.78 283.41 407.18 69.5 -- -- --

1974 54.09 127.82 181.92 23.3 -- -- --

1975 96.06 178.43 274.49 37.5 -- -- --

1976 113.01 366.44 479.45 101.1 -- -- --

1977 86.23 269.50 355.73 69.1 -- -- --

1978 108.65 333.69 442.34 88.7 -- -- --

1979 84.96 233.26 318.22 54.8 -- -- --

1980 60.17 112.06 172.23 18.0 -- -- --

1981 60.88 170.50 231.38 32.4 -- -- --

1982 89.00 514.20 603.20 158.7 -- -- --

1983 115.39 167.59 282.97 37.7 -- -- --

1984 122.53 262.19 384.72 63.2 -- -- --

1985 49.88 68.91 118.79 8.0 -- -- --

1986 92.52 356.64 449.17 90.8 -- -- --

1987 108.41 126.33 234.73 21.1 199.6 28.3 100.4

1988 38.38 102.37 140.74 16.2 186.2 28.3 100.4

1989 40.36 146.66 187.01 26.6 163.4 28.3 100.4

1990 76.27 190.95 267.22 38.7 168.1 28.3 100.4

1991 103.11 306.66 409.77 74.9 170.6 28.3 100.4

1992 66.30 199.31 265.61 48.5 165.9 28.3 100.4

1993 128.83 444.35 573.18 127.2 173.9 28.3 100.4

1994 120.16 203.50 323.65 49.3 193.6 28.3 100.4

1995 183.57 663.81 847.38 214.6 221.5 28.3 100.4

1996 179.48 522.32 701.80 158.2 245.9 28.3 100.4

1997 221.55 545.83 767.38 192.9 -- -- --

1998 174.77 458.38 633.15 152.8 -- -- --

1931-98 average 93.18 250.90 344.08 65.5 -- -- --

1950-98 average 98.39 271.04 369.40 72.2 -- -- --

1987-96 average 104.49 290.63 395.11 77.5 188.9 28.3 100.4

1From Carter, Driscoll, and Hamade (2001).

2From Carter, Driscoll, Hamade, and Jarrell (2001). Estimates are based strictly on estimated annual recharge and are intended only for estimation of 

long-term averages of springflow. 3From Carter, Driscoll, Hamade, and Jarrell (2001).

Table 13. Estimated annual hydrologic budget components for the Madison and Minnelusa aquifers, water years 1931-98, 

for the Black Hills of South Dakota and Wyoming–Continued

[All estimates in cubic feet per second. --, not determined]

Water year

Recharge1

Headwater 

springflow2

Artesian 

springflow3

Well

withdrawals3

Net

ground-water 

outflow Streamflow Precipitation Total 3
110 Hydrology of the Black Hills Area, South Dakota

Driscoll and Carter (2001) developed average 

budgets for the Madison and Minnelusa aquifer for 

1950-98 for the Black Hills area of South Dakota 

(study area) and for the Black Hills area of South 

Dakota and Wyoming (expanded area) (table 14). The 

budget for the study area includes an estimate of headwater springflow (78 ft3

/s) that was obtained by 

applying estimates of precipitation recharge to the area 

east of the ground-water divide on the Limestone 

Plateau (fig. 50). “Net recharge” of 214 ft3

/s was calculated by subtracting headwater springflow from the 

sum of streamflow and precipitation recharge. A breakdown between wells and artesian springs (28 and 

128 ft3/s, respectively) also is provided.

Table 14 also provides a budget for 1950-98 for 

an expanded area that includes large outcrops areas in 

Wyoming (fig. 54). For the expanded area, average 

precipitation recharge (271 ft3

/s) is considerably larger 

than for the study area; however, average streamflow 

recharge in the expanded area (98 ft3

/s) is only slightly 

larger. Average headwater springflow (72 ft3

/s) is 

slightly smaller because measured average flows of 

about 6 ft3

/s for Beaver and Cold Springs Creek are 

excluded. Both streams originate as headwater springs 

in South Dakota; however, both streams are depleted 

by streamflow losses that provide recharge to the 

Minnelusa aquifer just downstream (west) of the 

Wyoming border. Artesian springflow (169 ft3

/s) is 

larger and primarily accounts for artesian springflow 

measured along Stockade Beaver Creek and Sand 

Creek (fig. 34). Average net ground-water outflow 

(100 ft3

/s) is larger and reflects additional recharge 

within the expanded area.

Table 14. Average hydrologic budgets for the Madison and Minnelusa aquifers

[From Carter, Driscoll, Hamade, and Jarrell (2001) and Driscoll and Carter (2001)]

Units Streamflow 

recharge

Precipitation 

recharge

Headwater 

springflow Net recharge Well

withdrawals

Artesian 

springflow

 Net groundwater outflow 

from study 

area/expanded 

area

Black Hills of South Dakota (study area), water years 1950-98

Acre-feet 66,600 144,900 56,500 155,000 20,300 92,800 41,900

Cubic feet per 

second

92 200 178 214 2

28 128 58

Black Hills of South Dakota and Wyoming (expanded area), water years 1950-98

Acre-feet 71,000 196,300 52,200 215,100 20,300 122,400 72,400

Cubic feet per 

second

98 271 72 297 2

28 169 100

Black Hills of South Dakota and Wyoming (expanded area), water years 1987-96

Acre-feet 75,300 210,800 56,500 229,600 20,300 136,900 72,400

Cubic feet per 

second

104 291 178 317 28 189 100

1Includes 6 cubic feet per second of discharge for Beaver Creek and Cold Springs Creek in South Dakota, which subsequently recharges Minnelusa 

aquifer a short distance downstream in Wyoming. Thus, this flow is treated as a discharge for South Dakota; however, discharge and recharge are offsetting 

when both South Dakota and Wyoming are considered. 2Identical estimate used for well withdrawals in both areas. Areas considered in Wyoming primarily are recharge areas, where well withdrawals are 

minor.
Hydrologic Budgets 111

Precipitation recharge accounts for about 

73 percent of the recharge in the expanded area. Artesian springflow is the single largest discharge component and accounts for about 46 percent of the total 

outflows for the expanded area. Headwater springflow 

accounts for about 20 percent of the total outflow for 

the expanded area. Thus, most of the total outflow from 

the Madison and Minnelusa aquifers is from springflow, which then provides flow to area streams. Ground 

water flowing out of the expanded area accounts for 

about 27 percent of the total outflows. Well withdrawals account for about 8 percent of the total outflows.

Carter, Driscoll, Hamade, and Jarrell (2001) 

computed an average hydrologic budget for 1987-96 

for the Black Hills of South Dakota and Wyoming 

(expanded area) (table 14). For this period, change in 

storage was assumed equal to zero based on well 

hydrographs. Total springflow (including headwater 

and artesian springflow) averaged 267 ft3/s, which 

constitutes about 68 percent of estimated recharge; 

artesian springflow of 189 ft3/s was the single largest 

outflow component. 

Hydrologic budgets also were quantified by 

Carter, Driscoll, Hamade, and Jarrell (2001) for nine 

subareas (figs. 69 and 70) for periods of decreasing 

storage (1987-92) and increasing storage (1993-96), 

with changes in storage assumed equal but opposite 

(table 15). For most subareas, net ground-water outflow exceeds inflow, and ranges from 5.9 ft3

/s in the 

area east of Rapid City (subarea 4) to 48.6 ft3/s along 

the southwestern flanks of the Black Hills (subarea 9). 

Net ground-water inflow exceeds outflow for two subareas where the discharge of large artesian springs 

exceeds estimated recharge within subareas (subareas 7 

and 8).

Detailed budgets developed for the nine subareas 

included estimates of transmissivity and flow components for the individual aquifers at specific flow zones 

(figs. 69 and 70). The net outflow and inflows from the 

subarea budgets were used with Darcy’s Law to estimate transmissivity and flow across exterior flow 

zones corresponding with parts of the study area 

boundary and interior flow zones between subareas. 

For estimation purposes, it was assumed that transmissivities of the Madison and Minnelusa aquifers are 

equal in corresponding flow zones. The resulting transmissivity estimates ranged from about 100 to 

7,400 ft2

/d, which are consistent with estimates from 

other previous investigations (table 2). The highest 

transmissivity estimates are for areas in the northern 

and southwestern parts of the study area, and the lowest 

transmissivity estimates are along the eastern study 

area boundary. Because the transmissivity estimates 

presented by Carter, Driscoll, Hamade, and Jarrell 

(2001) are averages over large areas, much larger spatial variability in actual transmissivities can be 

expected.

The large changes in storage (table 15) for subarea 2 (about 69,000 acre-ft) result primarily from a 

large net outflow rate and a large differential in streamflow recharge rates between the dry and wet periods. 

The large storage change is consistent with large waterlevel fluctuations for observation wells in this subarea. 

In comparison, changes in storage are much smaller for 

subareas 3 and 5, both of which have much smaller differentials in both streamflow and precipitation recharge 

rates. Both of these subareas are influenced by artesian 

springs with highly variable discharge rates relative to 

most other artesian springs. Water-level data for wells 

in subarea 5 are sparse; however, hydrographs for wells 

in subarea 3 show relatively small water-level fluctuations.

Budgets for subareas in the southern Black Hills 

are consistent with geochemical interpretations (Naus 

and others, 2001), which indicate long flowpaths along 

the western and southwestern flanks contributing to 

large artesian springs in the area, as discussed in a following section. The average discharge of Beaver Creek 

Spring in subarea 7 exceeds estimated recharge for this 

subarea and probably is influenced by outflow from 

subarea 8, which is consistent with geochemical information. Similarly, discharge of artesian springs in subarea 8 is much larger than recharge in this subarea. 

Outflow from subarea 9 is a probable source for inflow 

to subarea 8, which again is substantiated by geochemical information.
112 Hydrology of the Black Hills Area, South Dakota

Figure 69. Subareas, generalized ground-water flow directions, and flow zones for the Madison aquifer. Estimated 

transmissivities and flow components for flow zones also are shown (from Carter, Driscoll, Hamade, and Jarrell, 2001).

Sundance

Beulah

Newcastle

Whitewood

Spearfish

Saint

Onge

DEADWOOD

Lead

BELLE FOURCHE

Newell

STURGIS

Blackhawk

Piedmont

Tilford

Box Elder 

Hill City

Hermosa

CUSTER

HOT SPRINGS

Edgemont

Minnekahta

Tinton Central

City

Roubaix

Nemo

Vale

Nisland

Hayward

Keystone

Rochford

Pringle

Fairburn

Buffalo Gap

Dewey

Cascade

Springs

Igloo

Provo

Oral

Rockerville

RAPID CITY

LIMESTONE PLATEAU

Redwater

Creek

Inyan Kara

Creek

Creek

Beaver

CHEYENNE

RIVER

Creek

Lance

Creek

Cr

Beaver

Creek

Creek

Cold

Springs

Sand

Stockade

Whoopup

N. Fork Rapid Cr

Belle Fourche

Reservoir

FOURCHE

Victoria

Spring

Rhoads Fork

Coolidge

Highland

Angostura

Reservoir

Castl e Cr

N. Fork Castle Cr

Hell

Canyon

Canyon

Red

Bear

Gulch

Creek

Crow

Sheridan

Lake

H ot Brook Canyon

Cox

Lake

Deerfield

Reservoir

Pactola

Reservoir

Indian Cr

Horse

Creek

Owl

BELLE

Creek

RIVER

REDWATER

R I VER

Creek

Cr

Little Spearfish

Spearfish

Creek

Spearfish

Whitewood

Creek

Creek

Bear

Butte

Elk

Elk

Creek

Creek

Creek

Boxelder

Rapid

Rapid

Creek

Creek

Creek

Spring

Creek

French

Creek

Creek

Creek

Grace

Creek

Creek

Creek

S. Fork

Redbird

Gillette

S. Fork Rapid Cr

Battle

French

Beaver

Beaver

Creek

Creek

Creek

Creek

Creek

Fall R

Hat

Creek

Creek

Horsehead

CHEYENNE

RIVER

Cottonwood

Hay Creek

Bottom

False

Creek

Spokane

Lame

Johnny

Higgins

Beaver

Cr

Whitetail

Cr

Cr

Cr Cr

Gulch

Annie

Squaw

Deadwood

Creek

Alkali

Iron Cr

Elk

Little

Creek

Castle

Castle

Creek

Creek

Bear Gulch

Cr Strawberry

Boles

Canyon

Canyon

Canyon

 Wind Cave

National Park

Jewel Cave

National

Monument

Mt. Rushmore

National

Memorial

CUSTER

STATE

PARK

Wind

Cave

Harney

Peak

x

Ellsworth

Air Force CROOK CO Base

WESTON CO

NIOBRARA CO

104o 104o

30' 103o

30'

103o

44o30'

44o

43o30'

BUTTE CO

LAWRENCE CO MEADE CO

PENNINGTON CO

CUSTER CO

FALL RIVER CO

WYOMING

SOUTH DAKOTA

3,600

5,800

6,600

3,600

3,400

3,800

4,000

4,200

4,400

5,000 5,200

4,800

5,400

5,600

6,000

6,200

4,200

6,400

4,000

3,800

3,200

3,400

3,600

4,200

2,600

2,600

2,800

4,000

2,800

2,800

3,000

3,000

6,600

6,000

6,400

6,200

5,000

3,600

4,000

3,200

3,600

4,600

3,400

3,400

3,800

3,800

4,000

4000

5000

6000

6200

732

0.9

1,463

1.8

732

1.3

90

0.3

1,045

2.8

310

1.7

510

1.3

510

4.6

510

4.2

3,196

43.7

5,589

36.9

591

19.7

7,393

12.2

4,349

11.0

5,589

36.9

591

19.7

7,393

12.2

4,349

11.0

0 10 20

0 10 20 MILES

KILOMETERS

OUTCROP OF MADISON LIMESTONE (from Strobel and others, 1999;

 DeWitt and others, 1989)

SUBAREA--Number is subarea number

POTENTIOMETRIC CONTOUR--Shows altitude at which water would have

 stood in tightly cased, nonpumping wells (modified from Strobel and others,

 2000a; Greene and Rahn, 1995). Contour interval 200 feet. Dashed where

 inferred. Datum is sea level

EXTERIOR INFLOW ZONE--Area where ground water is assumed

 to be entering the study area. Number is zone number

EXTERIOR OUTLOW ZONE--Area where ground water is assumed

 to be exiting the study area. Number is zone number

INTERIOR SUBAREA FLOW ZONE--Area where ground water is

 assumed to be crossing subarea boundaries. Number is zone

 number

EXPLANATION

SOUTH DAKOTA

WYOMING

Area

Black shown

Hills

GENERAL DIRECTION OF GROUND-WATER FLOW

DIRECTION OF FLOW ACROSS FLOW ZONE--Upper number is

 transmissivity estimate in feet squared per day; lower number is 8 estimated flow in cubic feet per second

732

1.3

LARGE ARTESIAN SPRING

0 10 20

0 10 20 MILES

KILOMETERS

Base modified from U.S. Geological Survey digital data, 1:100,000, 1977, 1979, 1981, 1983, 1985

Rapid City, Office of City Engineer map, 1:18,000, 1996; Universal Transverse Mercator projection, zone 13

10

10

11

9

8

7

6

5

4

2

3

12

14

13

12

1

1

8

1

2

3

4

5

6

7

9

8

1

2

3

4

5

6

7

9
Hydrologic Budgets 113

Figure 70. Subareas, generalized ground-water flow directions, and flow zones for the Minnelusa aquifer. Estimated 

transmissivities and flow components for flow zones also are shown (from Carter, Driscoll, Hamade, and Jarrell, 2001).

Sundance

Beulah

Newcastle

Whitewood

Spearfish

Saint

Onge

DEADWOOD

Lead

BELLE FOURCHE

Newell

STURGIS

Blackhawk

Piedmont

Tilford

Box Elder 

Hill City

Hermosa

CUSTER

HOT SPRINGS

Edgemont

Minnekahta

Tinton Central

City

Roubaix

Nemo

Vale

Nisland

Hayward

Keystone

Rochford

Pringle

Fairburn

Buffalo Gap

Dewey

Cascade

Springs

Igloo

Provo

Oral

Rockerville

RAPID CITY

LIMESTONE PLATEAU

Redwater

Creek

Inyan Kara

Creek

Creek

Beaver

CHEYENNE

RIVER

Creek

Lance

Creek

Cr

Beaver

Creek

Creek

Cold

Springs

Sand

Stockade

Whoopup

N. Fork Rapid Cr

Belle Fourche

Reservoir

FOURCHE

Victoria

Spring

Rhoads Fork

Coolidge

Highland

Angostura

Reservoir

Castl e Cr

N. Fork Castle Cr

Hell

Canyon

Canyon

Red

Bear

Gulch

Creek

Crow

Sheridan

Lake

H ot Brook Canyon

Cox

Lake

Deerfield

Reservoir

Pactola

Reservoir

Indian Cr

Horse

Creek

Owl

BELLE

Creek

RIVER

REDWATER

R I VER

Creek

Cr

Little Spearfish

Spearfish

Creek

Spearfish

Whitewood

Creek

Creek

Bear

Butte

Elk

Creek

Creek

Boxelder

Rapid

Rapid

Creek

Creek

Creek

Spring

Creek

French

Creek

Creek

Creek

Grace

Creek

Creek

Creek

S. Fork

Redbird

Gillette

S. Fork Rapid Cr

Battle

French

Beaver

Beaver

Creek

Creek

Creek

Creek

Creek

Fall R

Hat

Creek

Creek

Horsehead

CHEYENNE

RIVER

Cottonwood

Hay Creek

Bottom

False

Creek

Spokane

Lame

Johnny

Higgins

Beaver

Cr

Whitetail

Cr

Cr

Cr Cr

Gulch

Annie

Squaw

Deadwood

Creek

Alkali

Iron Cr

Elk

Little

Creek

Castle

Castle

Creek

Creek

Bear Gulch

Cr Strawberry

Boles

Canyon

Canyon

Canyon

 Wind Cave

National Park

Jewel Cave

National

Monument

Mt. Rushmore

National

Memorial

CUSTER

STATE

PARK

Wind

Cave

Harney

Peak

x

Ellsworth

Air Force CROOK CO Base

WESTON CO

NIOBRARA CO

104o 104o

30' 103o

30'

103o

44o30'

44o

43o30'

BUTTE CO

LAWRENCE CO MEADE CO

PENNINGTON CO

CUSTER CO

FALL RIVER CO

WYOMING

SOUTH DAKOTA

4,000

6,600

6,200

3,400

6,000

5,400

5,800

5,000 5,200

4,200

3,600

3,600

3,400

4,000

3,200

3,000

4,400

4,600

3,800

4,800

4,200

5,000

4,000

3,800

6,000

6,200

6,400 6,400

6,800

6,600

3,800

6,400

6,200 6,200

5,600

5,800

6,000

2,800

5,400

3,800

4,8004,600

4,800

3,600

4,600

3,400

4,400

4,000

3,600

2,600

2,800

3,000

3,200

3,400

3,800

4,000

4,200

4,400

4,600

4,200

4,000

3,800

3,600

2,600

732

0.4

1,463

2.8

732

4.8

90

0.6

1,045

3.9 1,463

2.4

434

0.8

310

3.4

510

1.3

712

3.4

510

3.1

510

1.3

3,196

27.5

3,196

8.1

3,196

15.4

591

5.3

7,393

11.5

4,349

13.0

732

0.4

1,463

2.8

732

4.8

90

0.6

1,045

3.9

1,463

2.4

434

0.8

310

3.4

510

1.3

712

3.4

510

3.1

510

1.3

3,196

27.5

3,196

8.1

3,196

15.4

591

5.3

7,393

11.5

4,349

13.0

510

3.1

OUTCROP OF MINNELUSA FORMATION (from Strobel and others,

 1999; DeWitt and others, 1989)

POTENTIOMETRIC CONTOUR--Shows altitude at which water would have 

 stood in tightly cased, nonpumping wells (modified from Strobel and others,

 2000b; Downie and Dinwiddie, 1988). Contour interval 200 feet, where

 appropriate.Dashed where inferred. Datum is sea level

EXPLANATION

GENERAL DIRECTION OF GROUND-WATER FLOW

SUBAREA--Number is subarea number

EXTERIOR INFLOW ZONE--Area where ground water is assumed to

 be entering the study area. Number is zone number

EXTERIOR OUTLOW ZONE--Area where ground water is assumed to

 be exiting the study area. Number is zone number

INTERIOR FLOW ZONE--Area where ground water is assumed to be

 crossing subarea boundaries. Number is zone number

8

DIRECTION OF FLOW ACROSS FLOW ZONE--Upper number is

 transmissivity estimate in feet squared per day; lower number is

 estimated flow in cubic feet per second

LARGE ARTESIAN SPRING

SOUTH DAKOTA

WYOMING

Area Black Shown Hills

0 10 20

0 10 20 MILES

KILOMETERS

Base modified from U.S. Geological Survey digital data, 1:100,000, 1977, 1979, 1981, 1983, 1985

Rapid City, Office of City Engineer map, 1:18,000, 1996; Universal Transverse Mercator projection, zone 13

25

30

15

16

15

24

27

25

26

23

22

21

20

19

18

17

28

29

30

31

32

1

2

3

6

7

8

9

4

5

1

2

3

6

7

8

9

4

5
114 Hydrology of the Black Hills Area, South Dakota

Table 15. Hydrologic budgets, by subareas, for the Madison and Minnelusa aquifers in the Black Hills area,

water years 1987-96 

[From Carter, Driscoll, Hamade, and Jarrell (2001). ft3/s, cubic feet per second; acre-ft, acre-feet]

Water year

Inflows (ft3/s) Outflows (ft3/s) Sum (ft3/s) Change in storage

Streamflow 

recharge

Precipitation 

recharge

Net

groundwater

inflow

Artesian

springflow

Well

withdrawals

Net

groundwater

outflow

Inflows Outflows ft3/s acre-ft

Subarea 1

1987 8.6 64.8 0.0 101.8 11.0 29.6 73.4 142.4 -69.0 -49,961

1988 5.9 53.9 .0 94.8 12.6 29.6 59.8 137.0 -77.2 -55,898

1989 6.1 65.5 .0 75.5 11.7 29.6 71.6 116.8 -45.2 -32,728

1990 7.5 83.9 .0 78.8 12.2 29.6 91.4 120.6 -29.2 -21,143

1991 8.5 122.7 .0 81.4 10.9 29.6 131.2 121.9 9.3 6,734

1992 6.6 86.5 .0 76.0 11.3 29.6 93.1 116.9 -23.8 -17,233

Average/sum1

1987-92

7.2 79.6 .0 84.7 11.6 29.6 86.8 125.9 -39.2 1-170,228

1993 9.8 170.2 .0 80.6 9.1 29.6 180.0 119.3 60.7 43,951

1994 11.3 100.7 .0 93.6 10.6 29.6 112.0 133.8 -21.8 -15,785

1995 15.9 260.0 .0 103.9 9.4 29.6 275.9 142.9 133.0 96,301

1996 16.1 202.9 .0 116.7 9.6 29.6 219.0 155.9 63.1 45,689

Average/sum1

1993-96

13.3 183.5 .0 98.7 9.7 29.6 196.7 138.0 58.8 1170,156

Average/sum1

1987-96

9.6 121.1 .0 90.3 10.8 29.6 130.7 130.8 .0 1-72

Subarea 2

1987 27.5 6.1 .0 .0 3.7 34.2 33.6 37.9 -4.3 -3,113

1988 5.8 5.9 .0 .0 4.2 34.2 11.7 38.4 -26.7 -19,333

1989 9.2 6.2 .0 .0 3.8 34.2 15.4 38.0 -22.6 -16,364

1990 15.5 5.8 .0 .0 4.1 34.2 21.3 38.3 -17.0 -12,309

1991 23.8 8.9 .0 .0 3.7 34.2 32.7 37.9 -5.2 -3,765

1992 12.3 5.7 .0 .0 3.8 34.2 18.0 38.0 -20.0 -14,481

Average/sum1

1987-92

15.7 6.4 .0 .0 3.9 34.2 22.1 38.1 -16.0 1-69,366

1993 32.9 16.0 .0 .0 3.1 34.2 48.9 37.3 11.6 8,399

1994 35.4 5.9 .0 .0 3.6 34.2 41.3 37.8 3.5 2,534

1995 58.5 31.7 .0 .0 3.2 34.2 90.2 37.4 52.8 38,231

1996 49.7 16.0 .0 .0 3.3 34.2 65.7 37.5 28.2 20,419

Average/sum1

1993-96

44.1 17.4 .0 .0 3.3 34.2 61.5 37.5 24.0 169,583

Average/sum1

1987-96

27.1 10.8 .0 .0 3.7 34.2 37.9 37.9 .0 1217
Hydrologic Budgets 115

Subarea 3

1987 10.6 1.6 0.0 1.6 0.6 9.8 12.2 12.0 0.2 145

1988 2.5 1.3 .0 .3 .6 9.8 3.8 10.7 -6.9 -4,996

1989 2.7 2.1 .0 .0 .6 9.8 4.8 10.4 -5.6 -4,055

1990 8.6 2.1 .0 .0 .6 9.8 10.7 10.4 .3 217

1991 9.1 4.6 .0 .1 .6 9.8 13.7 10.5 3.2 2,317

1992 5.6 1.8 .0 .0 .6 9.8 7.4 10.4 -3.0 -2,172

Average/sum1

1987-92

6.5 2.3 .0 .3 .6 9.8 8.8 10.7 -2.0 1-8,544

1993 10.0 5.3 .0 .1 .6 9.8 15.3 10.5 4.8 3,476

1994 10.9 1.7 .0 .4 .6 9.8 12.6 10.8 1.8 1,303

1995 12.0 10.3 .0 8.6 .6 9.8 22.3 19.0 3.3 2,389

1996 13.9 6.3 .0 8.2 .6 9.8 20.2 18.6 1.6 1,159

Average/sum1

1993-96

11.7 5.9 .0 4.3 .6 9.8 17.6 14.7 2.9 18,327

Average/sum1

1987-96

8.6 3.7 .0 1.9 .6 9.8 12.3 12.3 .0 1-217

Subarea 4

1987 33.3 2.7 .0 25.6 4.3 5.9 36.0 35.8 .2 145

1988 17.3 1.0 .0 25.6 4.2 5.9 18.3 35.7 -17.4 -12,599

1989 15.6 3.9 .0 25.6 3.4 5.9 19.5 34.9 -15.4 -11,151

1990 24.1 3.7 .0 25.6 5.0 5.9 27.8 36.5 -8.7 -6,299

1991 33.7 10.3 .0 25.6 6.7 5.9 44.0 38.2 5.8 4,200

1992 25.9 3.2 .0 25.6 10.5 5.9 29.1 42.0 -12.9 -9,340

Average/sum1

1987-92

25.0 4.1 .0 25.6 5.7 5.9 29.1 37.2 -8.1 1-35,045

1993 43.3 8.4 .0 25.8 10.2 5.9 51.7 41.9 9.8 7,096

1994 40.3 1.4 .0 25.6 11.1 5.9 41.7 42.6 -0.9 -652

1995 47.5 12.3 .0 27.1 9.1 5.9 59.8 42.1 17.7 12,816

1996 55.8 9.6 .0 30.1 7.6 5.9 65.4 43.6 21.8 15,785

Average/sum1

1993-96

46.7 7.9 .0 27.2 9.5 5.9 54.7 42.6 12.1 135,045

Average/sum1

1987-96

33.7 5.7 .0 26.2 7.2 5.9 39.3 39.3 .0 10

Table 15. Hydrologic budgets, by subareas, for the Madison and Minnelusa aquifers in the Black Hills area,

water years 1987-96–Continued

[From Carter, Driscoll, Hamade, and Jarrell (2001). ft3/s, cubic feet per second; acre-ft, acre-feet]

Water year

Inflows (ft3/s) Outflows (ft3/s) Sum (ft3/s) Change in storage

Streamflow 

recharge

Precipitation 

recharge

Net

groundwater

inflow

Artesian

springflow

Well

withdrawals

Net

groundwater

outflow

Inflows Outflows ft3/s acre-ft
116 Hydrology of the Black Hills Area, South Dakota

Subarea 5

1987 12.8 1.3 0.0 6.2 1.6 6.0 14.1 13.8 0.3 217

1988 2.4 .6 .0 2.4 1.6 6.0 3.0 10.0 -7.0 -5,068

1989 3.1 2.2 .0 1.2 1.6 6.0 5.3 8.8 -3.5 -2,534

1990 10.6 3.6 .0 1.6 1.6 6.0 14.2 9.2 5.0 3,620

1991 12.9 4.5 .0 3.5 1.6 6.0 17.4 11.1 6.3 4,562

1992 7.9 2.0 .0 4.5 1.6 6.0 9.9 12.1 -2.2 -1,593

Average/sum1

1987-92

8.3 2.4 .0 3.2 1.6 6.0 10.7 10.8 -0.2 1-796

1993 17.3 4.9 .0 7.1 1.6 6.0 22.2 14.7 7.5 5,430

1994 10.2 1.3 .0 10.8 1.7 6.0 11.5 18.5 -7.0 -5,068

1995 18.7 7.2 .0 11.3 1.6 6.0 25.9 18.9 7.0 5,068

1996 18.0 4.7 .0 21.0 1.7 6.0 22.7 28.7 -6.0 -4,344

Average/sum1

1993-96

16.1 4.5 .0 12.6 1.7 6.0 20.6 20.2 .4 11,086

Average/sum1

1987-96

11.4 3.2 .0 7.0 1.6 6.0 14.6 14.6 .0 1290

Subarea 6

1987 7.8 .3 .0 .0 .0 8.3 8.1 8.3 -0.2 -145

1988 2.7 .2 .0 .0 .0 8.3 2.9 8.3 -5.4 -3,910

1989 1.6 .6 .0 .0 .0 8.3 2.2 8.3 -6.1 -4,417

1990 5.1 .8 .0 .0 .0 8.3 5.9 8.3 -2.4 -1,738

1991 7.8 .9 .0 .0 .0 8.3 8.7 8.3 .4 290

1992 5.5 .7 .0 .0 .0 8.3 6.2 8.3 -2.1 -1,521

Average/sum1

1987-92

5.1 .6 .0 .0 .0 8.3 5.7 8.3 -2.6 1-11,440

1993 9.2 1.3 .0 .0 .0 8.3 10.5 8.3 2.2 1,593

1994 7.4 .3 .0 .0 .0 8.3 7.7 8.3 -0.6 -434

1995 13.0 2.5 .0 .0 .0 8.3 15.5 8.3 7.2 5,213

1996 13.9 1.5 .0 .0 .0 8.3 15.4 8.3 7.1 5,141

Average/sum1

1993-96

10.9 1.4 .0 .0 .0 8.3 12.3 8.3 4.0 111,513

Average/sum1

1987-96

7.4 .9 .0 .0 .0 8.3 8.3 8.3 .0 172

Table 15. Hydrologic budgets, by subareas, for the Madison and Minnelusa aquifers in the Black Hills area,

water years 1987-96–Continued

[From Carter, Driscoll, Hamade, and Jarrell (2001). ft3/s, cubic feet per second; acre-ft, acre-feet]

Water year

Inflows (ft3/s) Outflows (ft3/s) Sum (ft3/s) Change in storage

Streamflow 

recharge

Precipitation 

recharge

Net

groundwater

inflow

Artesian

springflow

Well

withdrawals

Net

groundwater

outflow

Inflows Outflows ft3/s acre-ft
Hydrologic Budgets 117

Subarea 7

1987 2.0 0.6 6.1 10.0 0.1 0.0 8.7 10.1 -1.4 -1,014

1988 .4 .4 6.1 10.0 .1 .0 6.9 10.1 -3.2 -2,317

1989 .4 .6 6.1 9.0 .1 .0 7.1 9.1 -2.0 -1,448

1990 1.0 .9 6.1 9.0 .1 .0 8.0 9.1 -1.1 -796

1991 1.6 1.1 6.1 8.1 .1 .0 8.8 8.2 .6 434

1992 1.0 1.2 6.1 8.0 .1 .0 8.3 8.1 .2 145

Average/sum1

1987-92

1.1 .8 6.1 9.0 .1 .0 8.0 9.1 -1.2 1-4,996

1993 2.2 2.1 6.1 9.1 .1 .0 10.4 9.2 1.2 869

1994 2.3 .6 6.1 9.5 .1 .0 9.0 9.6 -0.6 -434

1995 6.1 4.2 6.1 12.5 .1 .0 16.4 12.6 3.8 2,751

1996 6.1 1.2 6.1 11.1 .1 .0 13.4 11.2 2.2 1,593

Average/sum1

1993-96

4.2 2.0 6.1 10.6 .1 .0 12.3 10.7 1.7 14,779

Average/sum1

1987-96

2.3 1.3 6.1 9.6 .1 .0 9.7 9.7 .0 1-217

Subarea 8

1987 5.9 3.2 35.6 45.4 1.8 .0 44.7 47.2 -2.5 -1,810

1988 1.5 2.2 35.6 44.1 1.8 .0 39.3 45.9 -6.6 -4,779

1989 1.6 3.8 35.6 43.1 1.8 .0 41.0 44.9 -3.9 -2,824

1990 3.9 5.4 35.6 44.1 1.9 .0 44.9 46.0 -1.1 -796

1991 5.5 5.7 35.6 43.1 1.8 .0 46.8 44.9 1.9 1,376

1992 1.6 5.2 35.6 42.9 1.8 .0 42.4 44.7 -2.3 -1,665

Average/sum1

1987-92

3.3 4.3 35.6 43.8 1.8 .0 43.2 45.6 -2.4 1-10,499

1993 4.1 10.8 35.6 42.1 1.8 .0 50.5 43.9 6.6 4,779

1994 2.4 2.3 35.6 44.0 1.9 .0 40.3 45.9 -5.6 -4,055

1995 11.9 14.6 35.6 46.3 1.9 .0 62.1 48.2 13.9 10,065

1996 6.0 7.5 35.6 47.5 1.8 .0 49.1 49.3 -0.2 -145

Average/sum1

1993-96

6.1 8.8 35.6 45.0 1.9 .0 50.5 46.8 3.7 110,644

Average/sum1

1987-96

4.4 6.1 35.6 44.3 1.8 .0 46.1 46.1 .0 1145

Table 15. Hydrologic budgets, by subareas, for the Madison and Minnelusa aquifers in the Black Hills area,

water years 1987-96–Continued

[From Carter, Driscoll, Hamade, and Jarrell (2001). ft3/s, cubic feet per second; acre-ft, acre-feet]

Water year

Inflows (ft3/s) Outflows (ft3/s) Sum (ft3/s) Change in storage

Streamflow 

recharge

Precipitation 

recharge

Net

groundwater

inflow

Artesian

springflow

Well

withdrawals

Net

groundwater

outflow

Inflows Outflows ft3/s acre-ft
118 Hydrology of the Black Hills Area, South Dakota

Subarea 9

1987 0.0 24.6 0.0 9.0 2.2 48.6 24.6 59.8 -35.2 -25,487

1988 .0 20.7 .0 9.0 2.2 48.6 20.7 59.8 -39.1 -28,311

1989 .0 35.3 .0 9.0 2.2 48.6 35.3 59.8 -24.5 -17,740

1990 .0 46.1 .0 9.0 2.2 48.6 46.1 59.8 -13.7 -9,920

1991 .0 73.1 .0 8.8 2.2 48.6 73.1 59.6 13.5 9,775

1992 .0 44.6 .0 8.9 2.2 48.6 44.6 59.7 -15.1 -10,933

Average/sum1

1987-92

.0 40.7 .0 9.0 2.2 48.6 40.7 59.8 -19.0 1-82,616

1993 .0 98.2 .0 9.1 2.2 48.6 98.2 59.9 38.3 27,732

1994 .0 40.2 .0 9.7 2.3 48.6 40.2 60.6 -20.4 -14,771

1995 .0 106.4 .0 11.8 2.2 48.6 106.4 62.6 43.8 31,714

1996 .0 114.3 .0 11.3 2.3 48.6 114.3 62.2 52.1 37,724

Average/sum1

1993-96

.0 89.8 .0 10.5 2.3 48.6 89.8 61.3 28.5 182,399

Average/sum1

1987-96

.0 60.4 .0 9.6 2.2 48.6 60.4 60.4 .0 1-217

1Sum used for change in storage in acre-feet.

Table 15. Hydrologic budgets, by subareas, for the Madison and Minnelusa aquifers in the Black Hills area,

water years 1987-96–Continued

[From Carter, Driscoll, Hamade, and Jarrell (2001). ft3/s, cubic feet per second; acre-ft, acre-feet]

Water year

Inflows (ft3/s) Outflows (ft3/s) Sum (ft3/s) Change in storage

Streamflow 

recharge

Precipitation 

recharge

Net

groundwater

inflow

Artesian

springflow

Well

withdrawals

Net

groundwater

outflow

Inflows Outflows ft3/s acre-ft

Budgets for Other Bedrock Aquifers

Recharge estimates for the other bedrock aquifers consist only of precipitation recharge, which was 

derived by Driscoll and Carter (2001) using the yieldefficiency algorithm. Total yield, which is the sum of 

runoff plus recharge, was computed by applying the 

yield-efficiency algorithm to the estimates of precipitation on outcrops of the various bedrock formations. 

Individual ground-water budgets and an overall 

budget for all bedrock aquifers in the study area are presented in table 16. The Madison and Minnelusa aquifers, which have the largest outcrop areas of the major 

aquifers in the study area, dominate the overall groundwater budgets. In contrast, runoff from aquifer outcrops 

is dominated by the crystalline core area, with negligible runoff from outcrops of the Madison, Minnelusa, 

or Minnekahta aquifers. Combined recharge for all bedrock aquifers was estimated as 348 ft3/s, of which about 

84 percent is recharge to the Madison and Minnelusa 

aquifers. Total well withdrawals and springflow 

account for 259 ft3

/s, of which about 90 percent is from 

the Madison and Minnelusa aquifers. Net ground-water 

outflow from the study area was calculated as 89 ft3

/s 

and ranges from zero (assumed) for the crystalline core 

aquifers to about 58 ft3/s (65 percent) for the Madison 

and Minnelusa aquifers. For the Deadwood aquifer, 

well withdrawals and springflow were estimated as 

14 ft3

/s, which consists primarily of spring discharge in 

headwater areas of about 13 ft3/s. For the Madison and 

Minnelusa aquifers, springflow of 206 ft3

/s is much 

larger than well withdrawals of 28 ft3/s. For all other 

aquifers, springflow is small and was neglected; only 

well withdrawals are listed in table 16.
Hydrologic Budgets 119

Table 16. Average ground-water budgets for bedrock aquifers, water years 1950-98 [From Driscoll and Carter (2001). --, no data]

Units Precipitation Evapotran- spiration Total yield Runoff Precipitation recharge Streamflow recharge Total recharge Well with- drawals and springflow1 Net study area outflow

Crystalline Core (Precambrian, Tertiary, and Other Minor Units)

Acre-feet per year 1,084,500 964,200 120,300 116,700 3,600 0 3,600 3,600 0.0Cubic feet per second 1,497 1,331 166 161 5 0 5 5 0Inches per year 21.10 18.76 2.34 2.27 0.07 0 0.07 -- --

Deadwood

Acre-feet per year 128,200 110,100 18,100 3,600 14,500 0 14,500 10,100 4,400Cubic feet per second 177 152 25 5 20 0 20 114 6

Inches per year 23.24 19.96 3.28 0.65 2.63 0 2.63 -- --

Madison and Minnelusa

Acre-feet per year 1,021,500 876,600 144,900 0 144,900 66,600 211,500 169,500 41,900Cubic feet per second 1,410 1,210 200 0 200 92 292 1234 58

Inches per year 20.69 17.76 2.93 0 2.93 1.35 4.28 -- --

Minnekahta

Acre-feet per year 120,300 113,800 6,500 0 6,500 0 6,500 700 5,800Cubic feet per second 166 157 9 0 9 0 9 1 8Inches per year 20.02 18.94 1.08 0 1.08 0 1.08 -- --

Inyan Kara

Acre-feet per year 326,700 312,200 14,500 2,900 11,600 0 11,600 1,400 10,200Cubic feet per second 451 431 20 4 16 0 16 2 14Inches per year 17.84 17.05 0.79 0.16 0.63 0 0.63 -- --

Jurassic-Sequence Semiconfining Unit

Acre-feet per year 115,900 110,000 5,800 3,600 2,200 0 2,200 700 1,500Cubic feet per second 160 152 8 5 3 0 3 1 2Inches per year 18.35 17.43 0.92 0.57 0.35 0 0.35 -- --

Cretaceous-Sequence Confining Unit

Acre-feet per year 1,028,700 980,900 47,800 45,600 2,200 0 2,200 1,400 800Cubic feet per second 1,420 1,354 66 63 3 0 3 2 1Inches per year 17.24 16.44 0.80 0.76 0.04 0 0.04 -- --

Overall Budget for Bedrock Aquifers

Acre-feet per year 3,825,900 3,468,000 357,900 172,400 185,500 66,600 252,100 187,600 64,600Cubic feet per second 5,281 4,787 494 238 256 92 348 259 89Inches per year 19.46 17.64 1.82 0.88 0.94 1.35 1.28 -- --

1Includes estimated springflow of 13 cubic feet per second for Deadwood aquifer and 206 cubic feet per second for Madison and Minnelusa aquifers. For other aquifers, springflow is considered negligible and estimates include only well withdrawals.
120 Hydrology of the Black Hills Area, South Dakota

Surface-Water Budgets

Surface-water budgets were developed by 

Driscoll and Carter (2001) by consideration of stream 

channels within various specified areas, for which the 

basic continuity equation (eq. 2) was applied. Inflows 

considered included stream channels crossing boundaries for specified areas and net tributary flows generated within specified areas. Because net tributary flows 

(flows less depletions) were considered, flow depletions such as streamflow losses or diversions were not 

included as outflows. Storage changes for the four large 

Bureau of Reclamation reservoirs (Angostura, Deerfield, Pactola, and Belle Fourche) located within the 

study area were considered, with records of storage 

changes (positive change reflects increased storage) 

derived primarily from Miller and Driscoll (1998). 

Large storage increases occurred during 1950-98 for 

Angostura Reservoir (completed during 1950), Pactola 

Reservoir (completed during 1956), and Belle Fourche 

Reservoir, which had very low storage during 1950.

Average surface-water budgets for 1950-98 are 

provided in table 17. Inflows to the study area averaged 

about 106 and 146 ft3/s in the Cheyenne and Belle 

Fourche River drainages, respectively, with combined 

inflows averaging about 252 ft3

/s. Net tributary flows 

generated within the study area were estimated as about 

201 and 107 ft3

/s in the Cheyenne and Belle Fourche 

River drainages, respectively, with combined tributary 

flows of about 308 ft3

/s. Considering storage increases 

of about 7 ft3

/s in Bureau of Reclamation reservoirs, 

total outflows from the study area were estimated as 

about 554 ft3/s, with outflows of about 303 ft3

/s for the 

Cheyenne River drainage and 251 ft3

/s for the Belle 

Fourche River drainage. 

The primary surface-water outflows occur along 

the eastern side of the study area, of which the Cheyenne and Belle Fourche Rivers constitute the largest 

percentage of outflows (Driscoll and Carter, 2001). 

Estimated outflows include combined flows of about 

6 ft3/s in the Beaver Creek and Cold Springs Creek 

drainages, which drain a portion of the Limestone 

Plateau area, with flow to the west into Wyoming. Flow 

in both of these streams is lost to the Minnelusa 

Formation a short distance downstream of the 

Wyoming border. 

Combined Ground-Water and SurfaceWater Budgets

Combined average ground- and surface-water 

budgets are presented in figure 71A, which includes a 

detailed budget that shows complex ground- and 

surface-water interactions, and in figure 71B, which 

shows a more simplified budget. These budgets also 

are used to show consumptive uses of water that occur 

within the study area. Total consumptive use within the 

study area from both ground-water and surface-water 

resources was estimated by Driscoll and Carter (2001) 

as 218 ft3

/s, which includes well withdrawals 

(40 ft3

/s), reservoir evaporation (38 ft3/s), and consumptive withdrawals from streams (140 ft3/s). Consumptive uses consist primarily of consumptive 

irrigation withdrawals, which do not include unconsumed irrigation return flows. Most well withdrawals 

are consumed; however, in some locations (such as 

Rapid City), some portion of municipal well withdrawals may be unconsumed and returned to streams 

via wastewater treatment effluent.

Table 17. Average surface-water budgets for study area, water years 1950-98

[From Driscoll and Carter (2001). All in cubic feet per second]

Basin Study area inflows + Study area

tributaries

- Change in

storage

= Study area

outflows

Cheyenne River 105.8 201.2 4.5 302.5

Belle Fourche River 146.4 107.3 2.7 251.0

Combined 252.2 308.5 7.2 553.5
Hydrologic Budgets 121Figure 71. Schematic diagram showing average hydrologic budget components for study area, water years 1950-98 (from Driscoll and Carter, 2001). All values in cubic feet per second.

Madison

and

Minnelusa

PR (200)

Net recharge

(257)

Total

precipitation

(7,240)

Stream

outflow

(6)

P (1,410)

P (177)

P (1,497)

ET (152)

ET (1,331)

R (0) Wells

(1) R (5)

(18)

R (352) (473) (295)

(251) (473) (295)

Stream

inflows

(252)

Net Stream

outflows

(547)

Net stream

outflows

(547)

Stream

inflows

(252)

Loss zone bypass

(159)

ET (1,210)

ET (6,632)

Reservoir evaporation

and consumptive

withdrawals (178)

Total

consumptive use

(218)

Streamflow loss (6)

HW

(72) HW

(13)

HW

(6)

PR (256) Discharge to HW

streams in Wyoming

(6)

Streamflow losses

(92)

Discharge to

HW streams (85)

Artesian

springflow

(128)

Wells

(5)

Wells

(6)

Wells

(28)

R (161)

Artesian

springflow

(128)

Streamflow losses

(92)

Deadwood

PR (20)

NO (6)

NO (0)

NO (89) Wells (40)

NO (25)

NO (58)

Net precipitation recharge (122)

Net precipitation

recharge (165)

Total recharge to

Madison and

Minnelusa

(214)

P (4,156) ET (3,939)

Reservoir

storage and

evaporation

(38)

Consumptive

withdrawals

(140)

Crystalline

core area

PR (5)

All other

outcrops

PR (31)

SOUTH DAKOTA

WYOMING SOUTH DAKOTA

WYOMING

R (186)

A Detailed budget showing complex ground- and surface-water interactions for selected hydrogeologic unitsB Simplied budget showing components for all hydrogeologic units

P

R

ET

PR

HW

Wells

NO

PrecipitationRunoffEvapotranspirationPrecipitation rechargeHeadwater springflow

Well withdrawals

Net ground-water outflow
122 Hydrology of the Black Hills Area, South Dakota

A schematic diagram is presented as figure 72 

that shows the progression of average streamflow relative to surface geology and streamflow depletions. 

Streamflow upstream from loss zones to the Madison 

and Minnelusa aquifers averages about 251 ft3/s, 

which consists of headwater springflow from the Madison and Minnelusa aquifers (72 ft3/s) and Deadwood 

aquifer (13 ft3

/s) in the Limestone Plateau area, and of 

runoff from the Deadwood Formation (5 ft3/s) and 

crystalline core area (161 ft3/s). Streamflow losses to 

the Madison and Minnelusa aquifers average 92 ft3/s; 

thus, combined streamflow downstream from loss 

zones (loss-zone bypass) averages about 159 ft3

/s.

Artesian springflow (128 ft3/s) and runoff 

from outcrops beyond the Madison Limestone and 

Minnelusa Formation (186 ft3

/s) provide additional 

streamflow beyond the loss zones (fig. 72). Thus, 

average streamflow prior to major depletions, which 

result primarily from irrigation operations, is about 

473 ft3

/s. Reservoir evaporation and consumptive 

withdrawals of 178 ft3/s reduce average tributary flows 

to the Cheyenne and Belle Fourche Rivers to 295 ft3

/s. 

The tributary flows of 295 ft3

/s in figure 72 differ from 

the study area tributary flows of 308 ft3/s in table 12 by 

the reservoir storage change (7 ft3/s) and by combined 

flows for Beaver and Cold Springs Creeks (6 ft3

/s). The 

flows of Beaver and Cold Springs Creeks do not contribute to flows of the Cheyenne and Belle Fourche 

Rivers because streamflow losses occur a short distance downstream from the Wyoming border, as previously discussed.

Evaluation of Hydrologic Budgets

Numerous assumptions and estimates have been 

made in developing budgets for the complex hydrology 

of the Black Hills area. This section summarizes evaluations of budget components by Driscoll and Carter 

(2001), who concluded that methods used have provided reasonable budget estimates.

Hydrologic budgets for the Madison and Minnelusa aquifers are especially important because these 

aquifers dominate the overall ground-water budgets for 

the Black Hills area and heavily influence the surfacewater budget. Estimates of streamflow recharge, which 

are based largely on measured values, are considered 

Figure 72. Schematic showing generalized average streamflow (water years 1950-98) relative to surface geology and 

depletions (from Discroll and Carter, 2001).

50

0

100

150

200

250

300

350

400

450

500

STREAMFLOW,

IN CUBIC FEET PER SECOND

72

(72)

(13) (5)

(161)

(92)

(128)

(186)

(178)

85 90

251

159

287

473

295

Headwater

springflow

from

Madison and

Minnelusa

aquifers

Runoff from

Deadwood

Formation

Runoff from

crystalline

core area

Streamflow

losses to

Madison and

Minnelusa

aquifers Artesian springflow

and unconsumed

well withdrawals

Runoff from

outcrops beyond

Madison Limestone 

and Minnelusa

Formation

Net

consumption

from surface

water

Average

tributary flow

from study

area to

Cheyenne and

Belle Fourche

Rivers

Headwater

springflow

from

Deadwood

aquifer

Loss-zone

bypass
Madison and Minnelusa Flow System 123

more accurate than estimates of precipitation recharge, 

which have relatively large uncertainty associated with 

use of the yield-efficiency algorithm (and the assumptions on which the procedure is based). Short-term estimates for artesian springflow, which are based 

primarily on measured values, have relatively small 

uncertainty; however, extrapolation for longer term 

budgets (1950-98) introduces additional uncertainty. 

Uncertainties are larger for estimates of headwater 

springflow, which are based on yield potential for 

inferred areas contributing to ground-water discharge. 

Uncertainties are small for well withdrawals; thus, 

most of the uncertainties for estimates of net groundwater outflow from the study area are related to uncertainties for estimates of precipitation recharge. 

Detailed water-budget analyses for subareas (figs. 69 

and 70) provided confidence that estimates for all 

water-budget components are reasonable.

Budgets for other aquifers are based primarily on 

estimates of precipitation recharge, which were derived 

using the yield-efficiency algorithm. The assumed 

“recharge factors” used to apportion overall yield 

potential between runoff and recharge are another 

source of potential error. Considerable evidence exists 

that direct runoff is uncommon from outcrops of the 

Madison and Minnelusa aquifers; however, information regarding other aquifer outcrops is sparse.

The yield-efficiency algorithm also was used 

extensively in developing surface-water budgets and in 

estimating consumptive withdrawals for the study area. 

An analysis of streamflow depletion from streamflow 

losses indicated that estimates of total basin yield from 

the crystalline core area were reasonable. Evaluations 

of consumptive withdrawal estimates indicated that the 

yield-efficiency algorithm also performed well for 

areas beyond the Madison/Minnelusa outcrop band. 

Systematic biases in yield estimates undoubtedly 

would occur for various localized applications; however, evaluations performed have provided confidence 

that the algorithm systematically produces reasonable 

and reproducible estimates of basin yield from the spatial distribution of annual precipitation. Readers are 

cautioned that because of inherent, unexplained variability between annual yield and precipitation, estimates for individual years that are based on this 

algorithm have a relatively high level of uncertainty. 

Uncertainties associated with long-term estimates are 

much smaller, however.

MADISON AND MINNELUSA FLOW

SYSTEM

A major focus of the Black Hills Hydrology 

Study has been to obtain a better understanding of flow 

systems within the Madison and Minnelusa aquifers, 

which are extremely complex due to heterogeneity and 

anisotropy related to karst features and fractures and to 

interactions between the aquifers and surface-water 

resources. A variety of information has been considered in evaluating flowpaths, mixing conditions, and 

interactions. Much of the relevant background information, such as potentiometric-surface maps, hydrographs for colocated Madison and Minnelusa wells, 

major-ion chemistry, and hydrologic budgets, has been 

presented in previous sections. Background information regarding isotopes is presented in the following 

section.

Isotope Information

Various isotopes were used by Naus and others 

(2001) in evaluating the Madison and Minnelusa flow 

systems. The stable isotopes of oxygen (18O and 16O) 

and hydrogen (2H, deuterium; and 1H) were used to 

evaluate ground-water flowpaths, recharge areas, and 

mixing conditions. The radioisotope tritium (3H) provided additional information for evaluation of mixing 

conditions and ground-water ages. Background information for these isotopes and their distributions in 

the Black Hills area are discussed in the following 

sections.

Background Information and Composition of 

Recharge Water

This section presents background information 

regarding stable isotopes and tritium, which generally 

are not affected by interactions between minerals and 

ground water. The stable isotopes of oxygen and 

hydrogen are useful as flowpath tracers because of distinctive patterns in the Black Hills area resulting from 

meteorological influences. Tritium, which is subject to 

decay over time, is useful for age dating because large 

temporal variations of concentrations in precipitation 

have resulted from atmospheric testing of thermonuclear bombs during the 1950’s and 1960’s.

Stable isotope values are given in “delta notation,” which compares the ratio between heavy and 

light isotopes of a sample to that of a reference standard. Delta values are expressed as a difference, in 
124 Hydrology of the Black Hills Area, South Dakota

parts per thousand, or per mil (‰), from the reference 

standard. For example, the oxygen isotope value of a 

sample written in delta notation is:

A sample with a δ value of -20 ‰ is depleted by 

20 parts per thousand (2 percent) in the heavier isotope 

of the element relative to the standard. In this report, 

δ18O (18O/16O) and δD (deuterium/hydrogen) values 

are reported in per mil relative to Vienna Standard 

Mean Ocean Water (VSMOW) and are described as 

lighter and heavier in relation to each other. The lighter 

values are more negative relative to the heavier values, 

which are less negative.

Distinct isotopic signatures can result from isotope fractionation, which results from the loss of water 

vapor from a cooling air mass as it passes from its 

oceanic source over continents. As air masses rise to 

higher altitudes, lower temperatures and the subsequent formation of precipitation cause fractionation to 

occur within the cloud, and 18O and deuterium (D) are 

partitioned preferentially into the rain or snow. The 

heavy isotopes thus are distilled from the vapor, which 

is progressively depleted in 18O and D (Clark and Fritz, 

1997). A linear relation exists between δ18O and δD for 

samples collected in the Black Hills area (fig. 73); thus, 

subsequent discussions and illustrations refer only to 

δ18O for simplicity.

δ

18Osample

O/ 18 16Osample O/ 18 16Ostandard –

O/ 18 16Ostandard

= ------------------------------------------------------------------------

× 1 000 ‰ VSMOW. ,

Figure 73. Relation between δ18O and δD in Black Hills samples in comparison to the Global Meteoric Water 

Line (Craig, 1961) (from Naus and others, 2001).

δ18O, IN PER MIL (‰)

δD, IN PER MIL (‰)

EXPLANATION

-19 -18 -17 -16 -15 -14 -13 -12 -11 -10

-150

-80

-140

-130

-120

-110

-100

-90

Global Meteoric Water Line:

 δD = 8δ18O + 10

Artesian spring

Headwater spring - Deadwood aquifer

Headwater spring - Madison aquifer

Headwater spring - Minnelusa aquifer

Surface water - loss zone

Well - Deadwood aquifer

Well - Madison aquifer

Well - Minnekahta aquifer

Well - Minnelusa aquifer

#

#

#

#

#

#

#

#

# ##### #

##

###

##

## ##

# ##

#

#

#

# #

#

#

##

# #

#

#

###

#
Madison and Minnelusa Flow System 125

A generalized distribution of δ18O values for 

near-recharge areas is shown in figure 74. Sampling 

sites and values from which contours were derived also 

are shown in figure 74. Sites considered generally are 

located in or near recharge areas and probably are 

affected primarily by localized flowpaths. 

In near-recharge areas, δ18O values are influenced primarily by orography and storm patterns. Precipitation in the northern Black Hills generally is 

isotopically lighter than in the south because of relatively high altitudes and the influence of Pacific storms 

that are isotopically depleted in crossing the Rocky 

Mountains. The generally lower altitudes in the 

southern Black Hills, combined with warm weather 

patterns from the south-southeast, result in precipitation that is isotopically heavier than in the north (Back 

and others, 1983; Busby and others, 1983; Greene, 

1997). The resulting distribution of isotopes in nearrecharge areas of the Black Hills serves as a natural 

tracer for ground-water flowpaths.

Temporal variability in δ18O values for selected 

surface-water and ground-water sites is shown in 

figure 75; locations for these sites were provided by 

Naus and others (2001, p. 42-44). Temporal variability 

for ground-water samples generally is small relative to 

surface-water samples (fig. 75). The temporal variability in δ18O values for selected loss-zone streams 

(Spring Creek, Rapid Creek, and Boxelder Creek) 

(figure 75A) is due to seasonal variability in isotopic 

composition of precipitation. Data sets for selected 

headwater springs (Rhoads Fork and Castle Creek) are 

somewhat limited, but indicate less variability because 

of mixing associated with ground-water storage. Thus, 

for the wells and headwater springs shown in figure 74, 

variability in δ18O was assumed by Naus and others 

(2001) to be small and values were considered representative of average isotopic composition in nearrecharge areas.

 Tritium, which beta-decays to 3He with a halflife of 12.43 years (Clark and Fritz, 1997), is produced 

naturally in small concentrations by cosmic radiation in 

the stratosphere. Naturally occurring background concentrations of tritium in continental precipitation are 

estimated to range from 1 to 20 TU (tritium units), 

depending on location (Michel, 1989). One TU is 

defined as one 3

H atom per 1018 atoms of hydrogen, 

which is equivalent to 3.19 pCi/L (picocuries per liter) 

in water (International Atomic Energy Agency, 1981). 

Because of nuclear-bomb testing during the 1950’s and 

1960’s and a subsequent treaty limiting such tests, 

tritium concentrations in atmospheric water increased 

sharply in 1953, peaked in 1963, and then declined. 

Current sources of tritium, such as nuclear power production, contribute to atmospheric tritium concentrations that are slightly higher than background 

concentrations prior to nuclear testing.

Numerous factors limit capabilities for agedating of ground-water. One important factor is imprecise data for tritium concentrations in precipitation for 

the Black Hills area. Estimates by Naus and others 

(2001) are shown in figure 76, along with decay curves 

for selected 12-year increments that approximate the 

half-life decay of tritium. Estimates were derived primarily from data by Michel (1989) that were based on 

measurements at Ottawa, Canada (fig. 77) and other 

remote locations. Seasonal variability in tritium concentrations in precipitation (fig. 77) is another limiting 

factor. The composition of recharge water also can be 

affected by streamflow recharge, which is inherently 

older than precipitation. Especially large age differences can occur for streams such as Spearfish Creek or 

Rapid Creek, where large proportions of flow may 

originate from discharge of headwater springs.
126 Hydrology of the Black Hills Area, South Dakota

Figure 74. Generalized distribution of δ18O in surface water and ground water in near-recharge areas (from Naus and 

others, 2001).

-13

-14

-16

-15

-17

-12

N. Fork Rapid Cr

Belle Fourche

Reservoir

FOURCHE

Victoria

Rhoads Fork

Coolidge

Highland

Angostura

Reservoir

Castl e Cr

N. Fork Castle Cr

Hell

Canyon

Canyon

Red

Bear

Gulch

Cr

Crow

Sheridan

Lake

Hot Brook Canyon

Cox

Lake

Deerfield

Reservoir

Pactola

Reservoir

Indian Cr

Horse

Creek

Owl

BELLE

Creek

RIVER

REDWATER

R I VER

Creek

Cr

Little Spearfish

Spearfish

Creek

Spearfish

Whitewood

Creek

Creek

Bear

Butte

Elk

Creek

Creek

Boxelder

Rapid

Rapid

Creek

Creek

Spring

Creek

French

Creek

Creek

Creek

Grace

Creek

Creek

Creek

S. Fork

Gillette

S. Fork Rapid Cr

Battle

French

Beaver

Beaver

Creek

Creek

Creek

Creek

Creek

Fall R

Hat

Creek

Creek

Horsehead

CHEYENNE

RIVER

Cottonwood

Hay Creek

Bottom

False

Creek

Spokane

Lame

Johnny

Higgins

Beaver

Cr

Whitetail

Cr

Cr

Cr Cr

Gulch

Annie

Squaw

Deadwood

Creek

Alkali

Iron Cr

Elk

Little

Creek

Castle

Castle

Creek

Creek

Bear Gulch

Cr Strawberry

Boles

Canyon

Canyon

Redbird Canyon

Cold

Beaver

Spring

C s

reek

Creek

Whitewood

Spearfish

Saint

Onge

DEADWOOD

Lead

BELLE FOURCHE

Newell

STURGIS

Blackhawk

Piedmont

Tilford

Box Elder 

Hill City

Hermosa

CUSTER

HOT SPRINGS

Edgemont

Minnekahta

Tinton Central

City

Roubaix

Nemo

Vale

Nisland

Hayward

Keystone

Rochford

Pringle

Fairburn

Buffalo Gap

Dewey

Cascade

Springs

Igloo

Provo

Oral

Rockerville

RAPID CITY

LIMESTONE PLATEAU

 Wind Cave

National Park

Jewel Cave

National

Monument

Mt. Rushmore

National

Memorial

CUSTER

STATE

PARK

Wind

Cave

Harney

Peak

x

Ellsworth

Air Force

Base

BUTTE CO

LAWRENCE CO MEADE CO

PENNINGTON CO

CUSTER CO

FALL RIVER CO

WYOMING

SOUTH DAKOTA

-12.44

-14.63

-15.58

-12.28

-13.49

-12.59

-11.51

-11.58

-11.58

-16.01

-16.24

-15.74

-15.35

-16.96

-16.59

-16.93

-12.28

-13.49

-12.59

-11.51

-11.58

-11.58

-16.01

-16.24

-15.74

-15.35

-16.96

-16.59

-16.93

-12.59

-14.27

-13.41

-14.61

-14.06

-13.96 -16.56

-16.96

-16.41

-16.91

-17.59

-14.60

-14.27

-13.41

-14.61

-14.06

-13.96 -16.56

-16.96

-16.41

-16.91

-17.59

-14.60

-14.61

-12.25

-13.33

0 10 20

0 10 20 MILES

KILOMETERS

EXPLANATION

OUTCROP OF MINNELUSA

 FORMATION (from Strobel

 and others, 1999)

OUTCROP OF MADISON

 LIMESTONE (from Strobel

 and others, 1999)

HEADWATER SPRING--Number

 indicates δ18O value in per mil

WELL COMPLETED IN THE

 MINNEKAHTA AQUIFER--

 Number indicates δ18O value

 in per mil

CAVE--Number indicates δ18O

 value in per mil

LINE OF EQUAL δ18O--Interval

 1 per mil

STREAMFLOW GAGING

 STATION--Number indicates

 δ18O value in per mil. The δ18O

 values are contoured using the

 approximate centroid of the

 basin

-15

-13.33

-14.63

104o 45' 103o

30'

15' 103o

30'

44o

45'

15'

44o

45'

30'

43o

15'

Base modified from U.S. Geological Survey digital data,

1:100,000, 1977, 1979, 1981, 1983, 1985

Rapid City, Office of City Engineer map, 1:18,000, 1996

Universal Transverse Mercator projection, zone 13
Madison and Minnelusa Flow System 127

Figure 75. Temporal variation of δ18O for selected sites (from Naus and others, 2001). Graph A shows 

selected loss-zone streams and headwater springs. Graphs B and C show selected wells and artesian 

springs.

1986 1988 1990 1992 1994 1996 1998

A

B

C

CALENDAR YEAR

-18

-10

-17

-15

-13

-11

-16

-14

-12

δ18O, IN PER MIL (‰)

x x xxxxxx

-15.0

-12.5

-14.5

-14.0

-13.5

-13.0

-14.0

-11.5

-13.5

-13.0

-12.5

-12.0

x x x x

+

+

+ ++ + +

x

x

x x

x xx x

xx x x

x x

++

++ +

+

+

+

+++

Spring Creek

Rhoads Fork

x Castle Creek

Rapid Creek

Boxelder Creek

x

+

x

+

Black Hills Power & Light

Rapid City No. 6

Westberry Trails - Madison

Rapid City No. 10

Rapid City No. 8

Rapid City No. 9

Rapid City No. 5

City Springs

Highland Hills

Carriage Hills Main Well

Chapel Lane Madison

Rapid City No. 11

Hart Ranch

Pine Grove

Cleghorn Springs
128 Hydrology of the Black Hills Area, South Dakota

Figure 76. Estimated tritium concentrations in precipitation for Black Hills area and decay curves for selected years. 

Decay curves depict decayed tritium concentrations for selected sampling years. Maximum tritium concentrations of 

about 4,200 tritium units occurred in about 1963. Tritium has a half-life of about 12.43 years and decay curves are 

presented for selected 12-year increments that approximate this half-life. Using 1963 as an example, the tritium 

concentration in a sample collected in 1974 containing water recharged in 1963 would be equal to about 2,200 tritium 

units. The tritium concentration would have decayed by almost one-half to 1,100 tritium units for a sample collected 

12 years later in 1986, and again by about one-half to about 600 tritium units for a sample collected in 1998.

1940 1950 1960 1970 1980 1990 2000

CALENDAR YEAR

1

10,000

2

3

4

5

7

10

20

30

40

50

70

100

200

300

400

500

700

1,000

2,000

3,000

4,000

5,000

7,000

TRITIUM CONCENTRATION, IN TRITIUM UNITS

Tritium concentration in

 precipitation for Black

 Hills area

1974

Decay curves

1986

1998
Madison and Minnelusa Flow System 129

Another important consideration for age dating 

is ground-water mixing conditions, which can be 

highly variable because of large heterogeneity within 

the Madison and Minnelusa aquifers. Naus and others 

(2001) presented three simplified conceptual mixing 

models (fig. 78) that were used in evaluating groundwater ages and mixing conditions for the Black Hills 

area.

The first conceptual model (fig. 78A) depicts 

slug flow (often termed pipe or piston flow). The decay 

curves presented in figure 76 would be applicable for 

slug-flow conditions. For the Madison and Minnelusa 

aquifers, a slug-flow model could approximate groundwater flow conditions in dual-porosity settings if the 

dominant flow proportions are in continuous fractures 

and solution openings, with minimal contributions 

from the low-porosity matrix, dead-end fractures, or 

discontinuous solution openings.

The second conceptual model (fig. 78B) depicts 

the “immediate-arrival” mixing model, which generally is applicable for locations with water-table conditions within outcrop areas, such as headwater springs. 

For this scenario, water recharged during a given year 

is mixed with equal proportions of water recharged 

during previous years. For the hypothetical spring with 

a maximum traveltime of about 10 years that is shown 

in figure 78B, 10 percent of the water recharged during 

the current year is discharged as springflow during that 

same year. The remaining 90 percent of the water discharged is composed of equal proportions of water 

recharged during each of the previous 9 years. 

 The third conceptual model (fig. 78C) depicts 

the “time-delay” mixing model, which assumes a delay 

time before any recharge water reaches a discharge 

point. This model generally is appropriate where an 

upper confining unit is present and wells or springs are 

located some distance from outcrops areas, which is 

applicable for many locations around the periphery of 

the Black Hills, especially where confined conditions 

occur. For example, the hypothetical artesian well 

shown in figure 78C withdraws a mixture of water that 

was recharged during a 50-year period from 1929 to 

1978. The minimum traveltime (delay time) in this case 

is 20 years; in other words, the earliest arrival of 

recharge water is delayed by about 20 years before 

reaching the discharge point. The maximum traveltime 

is 70 years.

Figure 77. Monthly tritium concentrations in precipitation at Ottawa, Canada. Samples collected in Black Hills 

area of South Dakota also are shown (from Naus and others, 2001).

CALENDAR YEAR

Ottawa, Canada

Black Hills area

1950 1955 1960 1965 1970 1975 1980 1985 1990 1995 2000

10

10,000

20

30

40

50

70

100

200

300

400

500

700

1,000

2,000

3,000

4,000

5,000

7,000

TRITIUM, IN TRITIUM UNITS
130 Hydrology of the Black Hills Area, South Dakota

Figure 78. Schematic diagrams illustrating mixing models for age dating for various ground-water flow 

conditions (from Naus and others, 2001).

A Slug flow or pipe flow - negligible mixing with delayed arival

B Hypothetical water-table spring with maximum traveltime of 10 years - thorough mixing

with immediate arrival

C Well completed in artesian aquifer at considerable distance from recharge area - thorough

mixing with delayed arrival

1998

1998

1997 1996 1995 1994 1993 etc. Flow

direction

Water table

Potentiometric surface

Spring

Aquifer

outcrop

Aquifer

10% in storage

90% discharged

Confining unit

1997

1996

1995

1994

1993

1992

1991

1990

1998 Precipitation

1998 Precipitation

1989

1998

1988

1978

1968

1958

1948

1938

1928

Aquifer outcrop/recharge area

Well

Confining unit

Confining unit

Stream

channel

90% in storage

10% discharged

Water table
Madison and Minnelusa Flow System 131

The immediate-arrival and time-delay mixing 

models are based on various assumptions including 

equal annual recharge from year to year. Routine violation of this assumption (fig. 68) is one limitation for 

these conceptual models. A larger limitation is the nonhomogeneous hydraulic characteristics that commonly 

occur and result in nonuniform mixing conditions 

within the Madison and Minnelusa aquifers. Given the 

large range of hydraulic characteristics, the simplified 

models cannot address all of the complex mixing and 

flow conditions that occur. The models do, however, 

provide a mechanism by which finite numerical age 

estimates can be derived for water samples.

Decay-curve families for these two mixing 

models for various sample-collection years were presented by Naus and others (2001). Example curves for 

a 1995 sample-collection date, which was a midpoint 

for the main sampling period for the study, are presented in figure 79. The graph includes a family of 

curves depicting minimum traveltimes, or delay times, 

in 4-year increments. The 0-year delay curve in 

figure 79 is applicable for the immediate-arrival 

mixing model (fig. 78B), and the other curves are 

applicable for the time-delay mixing model (fig. 78C).

Using a sample concentration of 50 TU as an 

example, the immediate-arrival model (0-year delay 

curve) indicates two possible solutions, including equal 

annual recharge during about 1964-95 or 1930-95 

(fig. 79). Two solutions also are possible for time-delay 

scenarios with delay times less than about 24 years. 

Using the 20-year delay curve for the same example, 

the concentration would indicate recharge during about 

1969-75 or 1915-75. Because multiple solutions are 

possible for most sample concentrations, two or more 

samples usually are necessary for making general estimations of ground-water age.

Isotope Distributions and General Considerations

Distributions for δ18O and tritium are presented 

in this section. Various general considerations associated with the isotope distributions also are discussed. 

Distributions of δ18O values in Madison and 

Minnelusa wells and selected springs are shown in 

figure 80. Samples from sites considered representative of the isotopic composition of recharge in the study 

area were presented earlier in figure 74 and are 

excluded from figure 80. Distributions of stable isotopes generally are consistent with spatial patterns in 

recharge areas (fig. 74), with isotopically lighter precipitation generally occurring at higher altitudes and 

latitudes. 

Figure 79. Decay-curve family for delayed-arrival mixing model for a 1995 sampling date (from Naus and others, 

2001). Each curve shows average decayed tritium concentrations, for hypothetical mixes over time, for specified 

delay times that are provided in 4-year increments.

1800 1850 1900 1950 2000

CALENDAR YEAR

1

1,000

2

3

4

5

7

10

20

30

40

50

70

100

200

300

400

500

700

TRITIUM CONCENTRATION, IN TRITIUM UNITS

0 year

4 year

8 year

12 year

16 year

20 year

24 year

28 year

32 year

36 year

40 year
132 Hydrology of the Black Hills Area, South Dakota

Figure 80. Distribution of δ18O in samples from selected Madison and Minnelusa wells and springs in the Black Hills area 

(modified from Naus and others, 2001). Sampling dates are through 1998, with mean values shown for sites with multiple 

samples.

N. Fork Rapid Cr

Belle Fourche Reservoir

FOURCHE

Victoria

Spring

Rhoads Fork

Coolidge

Angostura

Reservoir

Castl e Cr

N. Fork Castle Cr

Hell

Canyon

Canyon

Red

Bear

Gulch

Creek

Crow

Sheridan

Lake

Hot Brook Canyon

Cox

Lake

Deerfield

Reservoir

Pactola

Reservoir

Indian Cr

Horse

Creek

Owl

BELLE

Creek

RIVER REDWATER

R I VER

Creek

Cr

Little Spearfish

Spearfish

Creek

Spearfish

Whitewood

Creek

Creek

Bear

Butte

Elk

Creek

Creek

Boxelder

Rapid

Rapid

Creek

Creek

Creek

Spring

Creek

French

Creek

Creek

Creek

Grace

Creek

Creek

Creek

S. Fork

Gillette

S. Fork Rapid Cr

Battle

French

Beaver

Beaver

Creek

Creek

Creek

Creek

Creek

Fall R

Hat

Creek

Creek

Horsehead

CHEYENNE

RIVER

Cottonwood

Hay Creek

Bottom

False

Creek

Spokane

Lame

Johnny

Higgins

Beaver

Cr

Whitetail

Cr

Cr

Cr Cr

Gulch

Annie

Squaw

Deadwood

Highland

Creek

Alkali

Iron Cr

Elk

Little

Creek

Castle

Castle

Creek

Creek

Bear Gulch

Cr Strawberry

Boles

Canyon

Canyon

Redbird Canyon

Cold

Beaver

Spring

C s

reek

Creek

Whitewood

Spearfish

Saint

Onge

DEADWOOD

Lead

BELLE FOURCHE

Newell

STURGIS

Blackhawk

Piedmont

Tilford

Box Elder 

Hill City

Hermosa

CUSTER

HOT SPRINGS

Edgemont

Minnekahta

Tinton Central

City

Roubaix

Nemo

Vale

Nisland

Hayward

Keystone

Rochford

Pringle

Fairburn

Buffalo Gap

Dewey

Cascade

Springs

Igloo

Provo

Oral

Rockerville

RAPID CITY

LIMESTONE PLATEAU

 Wind Cave

National Park

Jewel Cave

National

Monument

Mt. Rushmore

National

Memorial

CUSTER

STATE

PARK

Wind

Cave

Harney

Peak

x

Ellsworth

Air Force

Base

BUTTE CO

LAWRENCE CO MEADE CO

PENNINGTON CO

CUSTER CO

FALL RIVER CO

WYOMING

SOUTH DAKOTA

0 10 20

0 10 20 MILES

KILOMETERS

OUTCROP OF MINNELUSA FORMATION (from

 Strobel and others, 1999)

WELL COMPLETED IN MADISON AQUIFER--Number

 indicates δ18O value in per mil

WELL COMPLETED IN MINNELUSA AQUIFER--

 Number indicates δ18O value in per mil

ARTESIAN SPRING--Number indicates δ18O value in

 per mil

EXPLANATION

OUTCROP OF MADISON LIMESTONE (from Strobel

 and others, 1999)

104o 45' 103o

30'

15' 103o

30'

44o

45'

15'

44o

45'

30'

43o

15'

Base modified from U.S. Geological Survey digital data,

1:100,000, 1977, 1979, 1981, 1983, 1985

Rapid City, Office of City Engineer map, 1:18,000, 1996

Universal Transverse Mercator projection, zone 13

-16.36

-16.71

-17.19

-15.34

-16.95

-16.67

-13.79

-11.62

-11.68

-14.10

-14.86 -16.71

-15.43

-15.23

-15.40

-16.36

-16.71

-17.19

-15.34

-16.95

-16.67

-13.79

-11.62

-11.68

-14.10

-14.86 -16.71

-15.43

-15.23

-15.40

-13.79

-17.09

-17.28

-16.66

-16.65

-16.84

-15.04

-15.11

-16.13

-17.19

-15.61

-13.90

-13.68

-14.15

-14.13

-12.55

-17.80

-17.07

-11.89

-12.06

-11.75

-11.96

-12.13

-11.93

-15.97

-16.59

-14.88

-17.23

-16.32

-17.09

-17.28

-16.66

-16.65

-16.84

-15.04

-15.11

-16.13

-17.19

-15.61

-13.90

-13.68

-14.15

-14.13

-12.55

-17.80

-17.07

-11.89

-12.06

-11.75

-11.96

-12.13

-11.93

-15.97

-16.59

-14.88

-17.23

-16.32

-17.09

-12.55

-16.88

-16.98

-17.43 -17.07

-17.46

-15.90

-15.52

-13.61

-11.98

-11.50

-12.38

-15.15

-13.87

-14.27

-14.21

-15.88

-16.88

-16.98

-17.43 -17.07

-17.46

-15.90

-15.52

-13.61

-11.98

-11.50

-12.38

-15.15

-13.87

-14.27

-14.21

-15.88

-13.61

City 

Springs

Cleghorn/

Jackson

Springs

Tittle

Springs

Canyon

Lake

Creek

Creek

Creek

Creek

Creek

Spring

Creek

Rapid

Rapid

Victoria

Lime

MEADE COUNTY

PENNINGT PENNINGTON COUNTY ON COUNTY

RAPID CITY

Boxelder -14.38

-14.40

-14.18 -13.66

-13.45

-14.43

-13.25

-13.94

-13.69

-14.35 -14.28

-14.30

-14.40

-12.13 -12.09

-12.05

-12.09

-12.44 -12.35

-12.70 -12.77

-14.16

-14.38

-12.26

-12.66

-12.44

-12.78

-12.36

-12.27

-14.23

-14.38

-14.40

-14.18 -13.66

-13.45

-14.43

-13.25

-13.94

-13.69

-14.35 -14.28

-14.30

-14.40

-12.13 -12.09

-12.05

-12.09

-12.44

-12.35

-12.70 -12.77

-14.16

-14.38

-12.26

-12.66

-12.44

-12.78

-12.36

-12.27

-14.23

-14.35 -14.28

-12.44

-14.16

-14.38

-14.23

-12.51

-13.40

-13.65

-14.25 -13.95

-12.90 -13.90

-13.11

-13.83 -14.38

-13.70

-12.51

-13.40

-13.65

-14.25

-13.95

-12.90 -13.90

-13.11

-13.83 -14.38

-14.37 -13.70

-12.92
Madison and Minnelusa Flow System 133

The effects of recharge altitude are apparent in 

some areas. The δ18O values are lighter in the Madison 

aquifer than in the Minnelusa aquifer for 10 of 13 well 

pairs shown in figure 80 because the Madison aquifer 

generally is recharged at a higher altitude than the Minnelusa aquifer. The Madison aquifer also is influenced 

by preferentially larger volumes of isotopically light 

streamflow recharge, relative to the Minnelusa aquifer.

The δ18O values for samples from a Madison/

Minnelusa well pair at Tilford (fig. 80) are somewhat 

lighter than in nearby outcrop areas (fig. 74) and are 

distinctively lighter than for samples from a Madison/ 

Minnelusa well pair at Piedmont and for the artesian 

spring between Tilford and Piedmont. The spring and 

the Piedmont wells probably are influenced predominantly by recharge on nearby outcrops, whereas the 

Tilford wells probably are influenced predominantly 

by streamflow recharge from Elk Creek.

In the southern Black Hills, the δ18O values for 

samples from sites near Battle, Grace Coolidge, and 

French Creeks (fig. 80) are isotopically heavier than 

for any other part of the Black Hills area and are similar 

to values for nearby streamflow loss zones (fig. 74). 

Along the southern and southwestern flanks of the 

uplift, δ18O values for samples from most wells and 

springs (fig. 80) are much lighter than estimated values 

for near-recharge areas immediately nearby (fig. 74), 

indicating either recharge areas to the northwest or 

possible influence of regional flow from the west, as 

discussed in subsequent sections of this report.

Distributions of tritium in Madison and 

Minnelusa wells and selected springs are shown in 

figure 81. Large spatial variability in concentrations 

occurs near outcrop areas, which reflects large variability in mixing conditions and aquifer characteristics 

(heterogeneity). Most samples from wells that are far 

removed from outcrop areas have low, or nondetectable 

(<0.3 TU) tritium concentrations. Concentrations 

noted as <0.3 TU are equivalent to about <1.0 pCi/L, 

which is the method reporting limit (MRL) for most of 

the laboratory analyses that have been performed. Samples reported as <0.3 TU are assumed to be composed 

primarily of water recharged prior to initial influence of 

nuclear testing during the early 1950’s (pre-bomb 

water), regardless of mixing conditions (Naus and 

others, 2001).

Samples with tritium concentrations that equal 

or slightly exceed the MRL also are dominated by prebomb water, but probably are showing the presence of 

some proportion of modern water (recharged since the 

early 1950’s). For concentrations between 0.3 and 

1.0 TU, the detection of modern water is fairly certain, 

from an analytical standpoint, and would indicate 

either: (1) the initial arrival of modern water for slugflow conditions; or (2) at least some proportion of 

modern water for all mixing conditions.

Given the uncertainty in estimation of tritium 

concentrations in recent precipitation (since about 

1992) for the Black Hills area, concentrations as low as 

10 TU (fig. 76) may be possible for recently recharged 

water. Thus, for samples with tritium concentrations 

between about 1 and 5 TU, dominant proportions of 

pre-bomb water generally can be assumed. For concentrations greater than about 5 TU, it is difficult to make 

generalizations because of numerous possible mixing 

scenarios; however, for all mixing conditions, the probability of dominant proportions of modern water 

increases with increasing tritium concentrations.

Boxplots showing the distribution of tritium in 

samples collected during 1990-98 from wells, headwater springs, artesian springs, and streams upstream 

from loss zones in the Black Hills area are presented in 

figure 82. Concentrations for samples from streams 

upstream of loss zones generally are comparable with 

estimated concentrations for precipitation in the Black 

Hills area since about 1985 (fig. 76). As a group, headwater springs have the highest tritium concentrations, 

which generally indicates relatively large proportions 

of modern water. Potential age ranges for selected 

headwater springs were estimated by Naus and others 

(2001) using the immediate-arrival mixing model. 

Concentrations for samples generally are lower from 

wells than artesian springs, which probably tend to 

develop near preferential flowpaths that may be further 

enhanced by dissolution activity and thus are associated with relatively faster traveltimes than flowpaths to 

wells.

Tritium distributions for the ground-water sites 

(fig. 82) provide evidence that the mixing models illustrated in figure 78 have general applicability. The 

lower end of the range of tritium concentrations for 

headwater springs is much higher than for the wells and 

artesian springs, which is consistent with the concept of 

an immediate-arrival mixing model in outcrop areas for 

the Madison and Minnelusa aquifers. The lower end of 

the range of concentrations for wells and artesian 

springs is near zero, which supports applicability of the 

time-delay model in areas where an upper confining 

layer is present.
134 Hydrology of the Black Hills Area, South Dakota

Figure 81. Tritium occurrence for selected sample sites in Black Hills area (modified from Naus and others, 2001). 

Sites considered include only those sampled during the 1990’s with the most recent concentration shown for sites with 

multiple samples. Higher tritium concentrations indicate larger proportions of modern water.

N. Fork Rapid Cr

Belle Fourche

Reservoir

FOURCHE

Victoria

Spring

Rhoads Fork

Coolidge

Angostura

Reservoir

Castl e Cr

N. Fork Castle Cr

Hell

Canyon

Canyon

Red

Bear

Gulch

Creek

Crow

Sheridan

Lake

Hot Brook Canyon

Cox

Lake

Deerfield

Reservoir

Pactola

Reservoir

Indian Cr

Horse

Creek

Owl

BELLE

Creek

RIVER

REDWATER

R I VER

Creek

Cr

Little Spearfish

Spearfish

Creek

Spearfish

Whitewood

Creek

Creek

Bear

Butte

Elk

Elk

Creek

Creek

Creek

Boxelder

Rapid

Rapid

Creek

Creek

Creek

Spring

Creek

French

Creek

Creek

Creek

Grace

Creek

Creek

Creek

S. Fork

Gillette

S. Fork Rapid Cr

Battle

French

Beaver

Beaver

Creek

Creek

Creek

Creek

Creek

Fall R

Hat

Creek

Creek

Horsehead

CHEYENNE

RIVER

Cottonwood

Hay Creek

Bottom

False

Creek

Spokane

Lame

Johnny

Higgins

Beaver

Cr

Whitetail

Cr

Cr

Cr Cr

Gulch

Annie

Squaw

Deadwood

Highland

Creek

Alkali

Iron Cr

Elk

Little

Creek

Castle

Castle

Creek

Creek

Bear Gulch

Cr Strawberry

Boles

Canyon

Canyon

Redbird Canyon

Cold

Beaver

Spring

C s

reek

Creek

Whitewood

Spearfish

Saint

Onge

DEADWOOD

Lead

BELLE FOURCHE

Newell

STURGIS

Blackhawk

Piedmont

Tilford

Box Elder 

Hill City

Hermosa

CUSTER

HOT SPRINGS

Edgemont

Minnekahta

Tinton Central

City

Roubaix

Nemo

Vale

Nisland

Hayward

Keystone

Rochford

Pringle

Fairburn

Buffalo Gap

Dewey

Cascade

Springs

Igloo

Provo

Oral

Rockerville

RAPID CITY

LIMESTONE PLATEAU

 Wind Cave

National Park

Jewel Cave

National

Monument

Mt. Rushmore

National

Memorial

CUSTER

STATE

PARK

Wind

Cave

Harney

Peak

x

Ellsworth

Air Force

Base

BUTTE CO

LAWRENCE CO MEADE CO

PENNINGTON CO

CUSTER CO

FALL RIVER CO

WYOMING

SOUTH DAKOTA

0 10 20

0 10 20 MILES

KILOMETERS

EXPLANATION

TRITIUM CONCENTRATION, IN TRITIUM UNITS--Colors used

 represent the different categories: Madison aquifer (red);

 Minnelusa aquifer (green); headwater spring (cyan); and artesian

 spring (blue). The different sizes represent the tritium units

Less than 0.3

0.3 to less than 1.0

1.0 to less than 5.0

5.0 to less than 10.0

10.0 to less than 20.0

20.0 to less than 40.0

Greater than 40.0

104o 45' 103o

30'

15' 103o

30'

44o

45'

15'

44o

45'

30'

43o

15'

OUTCROP OF MINNELUSA FORMATION (from Strobel and

 others, 1999)

OUTCROP OF MADISON LIMESTONE (from Strobel and others,

 1999)

Base modified from U.S. Geological Survey digital data,

1:100,000, 1977, 1979, 1981, 1983, 1985

Rapid City, Office of City Engineer map, 1:18,000, 1996

Universal Transverse Mercator projection, zone 13

City Springs

Cleghorn/

Jackson

Springs

Tittle

Springs

Canyon

Lake

Creek

Creek

Creek

Rapid

Lime

RAPID

CITY

WELL COMPLETED IN MADISON

 AQUIFER

WELL COMPLETED IN MINNELUSA

 AQUIFER

HEADWATER SPRING

ARTESIAN SPRING
Madison and Minnelusa Flow System 135

The tritium distributions also provide evidence 

that purely slug-flow conditions probably are 

uncommon within the Madison and Minnelusa 

aquifers. For slug-flow conditions, water recharged 

between about 1962 and 1970 would have tritium concentrations of about 70 TU to as much as several hundred TU for all sample dates prior to 1998 (fig. 76). 

Tritium concentrations for the 96 ground-water samples collected since 1990, however, are uniformly less 

than 70 TU (fig. 82).

Flowpaths, Ages, and Mixing Conditions

A summary of interpretations regarding flowpaths, ages, and mixing conditions for the Madison and 

Minnelusa aquifers is presented in this section. Discussions include the Rapid City area and the northern and 

southern Black Hills. Regional flowpath considerations are included in discussions of the northern and 

southern Black Hills.

Rapid City Area

Extensive data sets of isotope information are 

available for the Rapid City area. In addition, dye 

testing in this area has provided useful information 

regarding flowpaths, relative ages of ground water, and 

mixing conditions. Evaluation of flowpaths and mixing 

conditions for the Rapid City area is especially complicated because: (1) recharge generally is dominated by 

streamflow losses, rather than precipitation on outcrop 

areas (Carter, Driscoll, and Hamade, 2001); and (2) 

large and variable withdrawals from the Madison and 

Minnelusa aquifers have occurred. Municipal production from the Madison aquifer has increased substantially since about 1990 (Anderson and others, 1999).

Dye testing has consisted of dye injection at a 

swallow hole in the loss zone of Boxelder Creek, with 

dye recovery documented at locations indicated in 

figure 83, many of which are located in the Rapid 

Creek drainage basin. The time required (in days) for 

the earliest arrival of dye from the dye injection point 

on Boxelder Creek to reach the various locations is 

shown in figure 83.

Figure 82. Boxplots of tritium concentrations for selected ground-water and surface-water samples 

collected during 1980-98 in the Black Hills area (from Naus and others, 2001).

SITE TYPES

TRITIUM CONCENTRATION, IN TRITIUM UNITS

EXPLANATION

10th percentile

25th percentile

Median

75th percentile

90th percentile

68 Number of samples

Minimum

Maximum

68 9 19 12

Wells Headwater

springs

Artesian

springs

Streams

upstream from

loss zones

0

70

10

20

30

40

50

60
136 Hydrology of the Black Hills Area, South Dakota

Figure 83. Concentrations of δ18O in Madison and Minnelusa aquifers in Rapid City area (modified from Naus and 

others, 2001). Average δ18O values for streamflow loss zones also are shown. In addition, traveltimes and tritium 

concentrations for sites at which dye recovery was reported by Greene (1999) are shown.

103o22'30" 20' 17'30" 15' 103o12'30"

44o

10'

7'30"

5'

2'30"

44o

City Springs

Cleghorn/

Jackson

Springs

Tittle

Springs

Canyon

Lake

Creek

Creek

Creek

Creek

Spring

Creek

Rapid

Rapid

Victoria

Lime

MEADE COUNTY

PENNINGT PENNINGTON COUNTY ON COUNTY

RAPID CITY

Creek

Boxelder

-12.26

-14.38

-14.40

-14.18

-13.66

-13.45

-14.43

-13.25

-13.94

-13.69

-14.35

-14.28

-14.30

-14.40

-12.13 -12.09

-12.05 -12.09

-12.44 -12.35

-12.77

-12.70

-14.16

-14.38

-12.26

-12.66

-12.44

-12.78

-12.36

-12.27

-14.23

-14.38

-14.40

-14.18

-13.66

-13.45

-14.43

-13.25

-13.94

-13.69

-14.35

-14.28

-14.30

-14.40

-12.13 -12.09

-12.05 -12.09

-12.44 -12.35

-12.77

-12.70

-14.16

-14.38

-12.26

-12.66

-12.44

-12.78

-12.36

-12.27

-14.23

Area in Madison aquifer where

δ18O values are indicative of

recharge primarily from Spring

Creek

Area in Madison aquifer where

δ18O values are indicative of

recharge from Boxelder Creek

δ

some recharge from Boxelder

Creek

-13.40

-13.65

-14.25 -13.95

-12.90

-12.51

-12.51

-13.90

-13.11

-13.83

-14.38

-13.70

-13.40

-13.65

-14.25 -13.95

-12.90

-12.51

-12.51

-13.90

-13.11

-13.83

-14.38

-13.70

41

3.7

Dye injection

point on

Boxelder

CreekX

49

4.7

41

30 3.7

40.8

26

31.0

49

4.7

41

30 3.7

40.8

26

31.0

30

14.5

-14.45

-14.37

-12.92

OUTCROP OF MADISON LIMESTONE

 (from Strobel and others, 1999)

OUTCROP OF MINNELUSA FORMATION

 (from Strobel and others, 1999)

AVERAGE OF δ18O VALUES FOR STREAM

 AT STREAMFLOW LOSS ZONE

EXPLANATION

WELL COMPLETED IN MADISON AQUIFER--

 Number indicates δ18O value in per mil

DYE RECOVERY AT WELL OR SPRING--Upper number indicates

 the time required, in days, for the earliest arrival of dye from injection

 point on Boxelder Creek. Lower number indicates tritium concentration,

 in tritium units

WELL COMPLETED IN MINNELUSA AQUIFER--Number indicates

 δ18O value in per mil

ARTESIAN SPRING--Number indicates δ18O value in per mil

1 2 MILES

0 1 KILOMETERS 2

0

DAKOTA

SOUTH

Study

area

Area

shown

-14.2

-15.4

-12.6

-12.6

Base modified from U.S. Geological Survey digital data, 1:100,000, 1977, 1979, 1981, 1983, 1985

Rapid City, Office of City Engineer map, 1:18,000, 1996; Universal Transverse Mercator projection, zone 13
Madison and Minnelusa Flow System 137

A distinct division of stable isotope values is 

apparent for the Madison aquifer along Rapid Creek 

(fig. 83). Areas south of Rapid Creek reflect isotopic 

composition similar to Spring Creek (fig. 83), which is 

isotopically heavier than Rapid Creek and Boxelder 

Creek (fig. 75). Sites north of Rapid Creek generally 

reflect isotopically lighter composition similar to that 

of Rapid Creek and Boxelder Creek, indicating a combination of recharge from these areas. Areas that probably have some influence from water recharged in 

Boxelder Creek also are shown in figure 83. The δ18O 

values for samples from Minnelusa wells in the Rapid 

City area show a general gradation from north to south 

of lighter to heavier values, with no distinct division, 

which probably indicates larger influence from precipitation recharge, than for the Madison aquifer in this 

area.

Results of 1993 dye testing in the Rapid City 

area (Greene, 1999), in combination with tritium samples, provide relatively definitive age-dating information for several sites. A tritium concentration of 

58.1 TU was measured at the dye-injection location 

along Boxelder Creek. Two of the wells with dye 

recovery (within less than 50 days of injection) had 

detectable, but low, tritium values (3.7 and 4.7 TU; 

fig. 83), which generally would be considered indicative of large proportions of pre-bomb water. This inference is reasonable, but somewhat misleading because 

the small proportions of modern water in the mix consist of extremely modern water. Unequal mixing of 

about 5 to 10 percent very recent water (tritium concentration of about 58 TU) with 90 to 95 percent prebomb water (0 TU) was suggested by Naus and others 

(2001) as a viable mix for these sites. This scenario is a 

noteworthy example of unequal mixing conditions that 

can occur in a dual-porosity system.

Time-series δ18O and tritium data provide useful 

information regarding mixing conditions and general 

ages for numerous other sampling sites in the Rapid 

City area. Sites with minimal variability in δ18O values 

generally have tritium data indicative of dominant proportions of pre-bomb water, reflecting generally thorough mixing conditions. A number of sites, however, 

showed response to temporal δ18O trends in streamflow recharge (fig. 75), with associated tritium data 

generally indicating relatively large proportions of 

modern recharge. Water from several large Madison 

production wells located along Rapid Creek had 

changes in δ18O values indicative of changes in capture 

zones associated with recent production. Potential 

changes in ground-water age characteristics at several 

wells also were indicated by tritium concentrations for 

sequential samples.

Northern Black Hills

Naus and others (2001) examined the possible 

influence of regional flow components from the west 

for the Madison aquifer in the northern part of the study 

area. Samples from two Madison wells just north of the 

study area (fig. 84) show influence of regional flow, 

with δ18O values (-18.13 ‰ and -19.66 ‰) that are 

much lighter than any of the values in the Black Hills 

recharge areas (fig. 74). Busby and others (1983) and 

Plummer and others (1990) noted samples from 

Madison wells near recharge areas in Wyoming near 

the Bighorn Mountains with δ18O values as light as 

-18.5 ‰ and near the Laramie Mountains as light as 

-19.25 ‰. Concentrations of common ions for samples 

from the two wells just north of the study area (Busby 

and others, 1991) are approximately an order of magnitude higher than for samples from wells along the 

northwestern flank of the Black Hills and are consistent 

with a regional flowpath trending northeasterly from 

the Bighorn Mountains in Wyoming (fig. 17).

The δ18O value of -17.80 ‰ for a well sample 

northeast of Belle Fourche (fig. 84) indicates possible 

minor influence from regional flow; however, the value 

of -17.07 ‰ for the well sample at Belle Fourche provides no indication of regional influence. Ion concentrations for the well sample northeast of Belle Fourche 

are slightly higher than for the well sample at Belle 

Fourche (fig. 34), but are much lower than concentrations for samples from the two wells just north of the 

study area (Busby and others, 1991). Ion concentrations also are low for a sample from a well just north of 

Nisland (fig. 34). Thus, Naus and others (2001) concluded that regional flowpaths in the Madison aquifer 

are largely deflected to the north of the study area. 

Regional δ18O values are not available for the Minnelusa aquifer; however, values for Minnelusa wells 

along the northwestern flank of the uplift (fig. 84) are 

similar to those in near-recharge areas to the south and 

west (fig. 74).

Several large artesian springs located along the 

northern axis of the uplift are a major hydrologic feature of the northern Black Hills area. These springs are 

a major discharge area for the Madison and Minnelusa 

aquifers (Klemp, 1995), with cumulative discharge of 

all artesian springs along the northern flank estimated 

as 90 ft3/s for 1987-96 (Carter, Driscoll, Hamade, and
138 Hydrology of the Black Hills Area, South Dakota

Figure 84. Distribution of δ18O in selected Madison wells and springs and generalized flowpaths, based on δ18O 

values, in the Black Hills of South Dakota and Wyoming (from Naus and others, 2001).

Hulett

Sundance

Upton

Newcastle

Whitewood

Spearfish

Saint

Onge

DEADWOOD

Lead

BELLE FOURCHE

Newell

STURGIS

Blackhawk

Piedmont

Tilford

Box Elder 

Hill City

Hermosa

CUSTER

HOT SPRINGS

Edgemont

Minnekahta

Tinton

Central

City

Roubaix

Nemo

Vale

Nisland

Hayward

Keystone

Rochford

Pringle

Fairburn

Buffalo Gap

Dewey

Cascade

Springs

Igloo

Provo

Oral

Rockerville

RAPID CITY

LIMESTONE PLATEAU

BELLE

RIVER

FOURCHE

Redwater

Creek

Inyan

Kara

Creek

Creek

Beaver

CHEYENNE

RIVER

Creek

Lance

Crow

Horse

Creek

Cr

Beaver

Creek

Creek

Cold

Springs

Sand

Stockade

Whoopup

N. Fork Rapid Cr

Belle Fourche

Reservoir

FOURCHE

Victoria

Spring

Rhoads Fork

Coolidge

Highland

Angostura

Reservoir

Castle Cr

N. Fork Castle Cr

Hell

Canyon

Canyon

Red

Bear

Gulch

Creek

Crow

Sheridan

Lake

H ot Brook Canyon

Cox

Lake

Deerfield

Reservoir

Pactola

Reservoir

Indian Cr

Horse

Creek

Owl

Creek

BELLE

RIVER

REDWATER

R I VER

Creek Cr

Little Spearfish

Spearfish

Creek

Spearfish

Whitewood

Creek

Creek

Bear

Butte

Elk

Elk

Creek

Creek

Creek

Boxelder

Rapid

Rapid

Creek

Creek

Creek

Spring

Creek

French

Creek

Creek

Creek

Grace

Creek

Creek

Creek

S. Fork

Redbird

Gillette

S. Fork Rapid Cr

Battle

French

Beaver

Beaver

Creek

Creek

Creek

Creek

Creek

Fall R

Hat

Creek

Creek

Horsehead

CHEYENNE

RIVER

Cottonwood

Hay Creek

Bottom

False

Creek

Spokane

Lame

Johnny

Higgins

Beaver

Cr

Whitetail

Cr

Cr

Cr Cr

Gulch

Annie

Squaw

Deadwood

Creek

Alkali

Iron Cr

Elk

Little

Creek

Castle

Castle

Creek

Creek

Bear Gulch

Cr Strawberry

Boles

Canyon

Canyon

Canyon

 Wind Cave

National Park

Jewel Cave

National

Monument

Mt. Rushmore

National

Memorial

CUSTER

STATE

PARK

Wind

Cave

Harney

Peak

x

Ellsworth

Air Force

CROOK CO Base

WESTON CO

NIOBRARA CO

104o 104o30' 103o30'

103o

44o30'

45o

44o

43o30'

BUTTE CO

LAWRENCE CO MEADE CO

PENNINGTON CO

CUSTER CO

FALL RIVER CO

WYOMING

SOUTH DAKOTA

-15.43

-15.40

-17.19

-15.34

-16.95

-16.67

-15.43

-14.10

-15.40

-17.19

-15.34

-16.95

-16.67

-15.40

-18.13

-19.66

-17.07 -17.80

-17.09

-17.85

-17.49

267

-18.18

-17.60

-18.15

-17.75

-17.45

-17.60

-17.40

-17.66

-17.95

-18.13

-19.66

-17.07 -17.80

-17.09

-17.85

-17.49

-18.18

-17.60

-18.15

-17.75

-17.45

-17.60

-17.40

-17.66

-17.95

-17.09

0 10 20

0 10 20 MILES

KILOMETERS

EXPLANATION

SOUTH DAKOTA

WYOMING

Study Area area shown

Black

Hills

OUTCROP OF MADISON LIMESTONE (from

 Strobel and others, 1999; DeWitt and others,

 1989)

OUTCROP OF MINNELUSA FORMATION

 (from Strobel and others, 1999; DeWitt and

 others, 1989)

GENERALIZED FLOWPATH

WELL COMPLETED IN MADISON AQUIFER--

 Number indicates δ18O value in per mil

ARTESIAN SPRING--Number indicates δ18O value

 in per mil

Base modified from U.S. Geological Survey digital data, 1:100,000, 1977, 1979, 1981, 1983, 1985

Rapid City, Office of City Engineer map, 1:18,000, 1996; Universal Transverse Mercator projection, zone 13
Madison and Minnelusa Flow System 139

Jarrell, 2001). The δ18O values (fig. 80) and tritium 

concentrations (fig. 81) for most of these springs are 

quite similar, which probably indicates generally thorough mixing conditions resulting from large discharges 

(and associated large recharge areas). The tritium concentrations are consistently indicative of modern 

recharge, which does not necessarily preclude regional 

flow contributions, but confirms Black Hills recharge 

as the primary recharge component. Multiple tritium 

samples are available for several springs and wells 

along the northern flank of the uplift. General evaluations of potential age ranges derived using the timedelay mixing model were discussed by Naus and others 

(2001).

Results of water-budget analyses for the 

Madison and Minnelusa aquifers (figs. 69 and 70, 

table 15) support the geochemical interpretation of 

minimal influence from regional flowpaths in the 

northern part of the study area. For subarea 1, which 

includes the large artesian spring area along the 

northern axis, ground-water outflow is estimated to 

exceed inflow by about 30 ft3/s. This analysis does not 

necessarily preclude a regional ground-water flow 

component in the northern part of the study area, but 

does support the conclusion of dominance by recharge 

in the Black Hills area.

Southern Black Hills

Naus and others (2001) also evaluated the possible influence of regional flow components for the 

Madison aquifer in the southern part of the study area. 

Light δ18O values from samples for several sites west 

of the study area in Weston County (fig. 84) are indicative of a possible transition zone between regional and 

areal flowpaths. Ion concentrations for samples from 

wells in this area (Busby and others, 1991) generally 

showed little, if any, influence of regional flow, however. High ion concentrations for samples from several 

Madison wells in the southwestern corner of the study 

area (fig. 34) indicate possible regional influence, but 

cannot necessarily be distinguished from basinward 

increases in constituent concentrations. Farther north, 

regional influence probably is minor or negligible.

Several large artesian springs located along the 

southern axis of the Black Hills uplift comprise another 

major discharge area for the Madison and Minnelusa 

aquifers (Whalen, 1994; Hayes, 1999). For subareas 7 

and 8 (figs. 69 and 70), artesian spring discharge averaged about 54 ft3/s during 1987-96 (table 15). Combined streamflow and precipitation recharge for these 

subareas averaged only about 14 ft3

/s; thus, much of 

the recharge for the springs probably occurs in 

subarea 9, where recharge averaged about 60 ft3

/s. 

Considering the three subareas (7, 8, and 9) collectively, ground-water outflow is estimated to exceed 

inflow by about 7 ft3

/s. This analysis does not necessarily preclude a regional ground-water flow component in the southern part of the study area, but does 

indicate dominance by recharge in the Black Hills area.

Dominance by recharge in the Black Hills area 

also is indicated by the δ18O values for the large 

springs (fig. 84), which are notably heavier than 

reported regional values (Busby and others, 1983; 

Plummer and others, 1990) and essentially preclude 

substantial influence from regional flowpaths. This 

conclusion is supported by ion concentrations for the 

springs (fig. 34 and 35), which are insufficient to be 

indicative of regional flow. High sulfate concentrations 

for several of the springs reflect influence from dissolution of anhydrite within the Minnelusa Formation.

Low, but detectable, tritium concentrations in the 

large springs (fig. 81) confirm the influence of recharge 

from within the study area, but indicate relatively long 

traveltimes. This is consistent with the δ18O values, 

which indicate potential recharge areas extending 

along the entire southwestern flank of the uplift. Generally low tritium concentrations for large springs in 

the southern Black Hills, relative to concentrations for 

springs along the northern axis, may be influenced by 

generally smaller recharge rates in the southern Black 

Hills.

The δ18O value for Beaver Creek Spring 

(-14.10 ‰; figs. 80 and 84) located just northwest of 

Buffalo Gap is much lighter than estimated values for 

nearby outcrop areas and samples from nearby wells, 

which indicates a possible flowpath extending from the 

general Hot Springs area. This interpretation also is 

supported by a low tritium value for Beaver Creek 

Spring (fig. 81), which indicates generally long traveltimes, and by the water-budget analysis, which indicates a substantial flow component to the spring from 

west of the uplift axis (figs. 69 and 70, table 15).

Tritium concentrations for artesian springs along 

Battle and Grace Coolidge Creeks indicate younger 

water than for several nearby wells (fig. 81), which is 

consistent with development of artesian springs along 

preferential flowpaths. The discharges of these springs 

(which are located in subarea 5) are highly variable 

(table 15), and probably are influenced primarily by 

variability in streamflow recharge, which dominates 

recharge in this subarea.
140 Hydrology of the Black Hills Area, South Dakota

Interactions Between Aquifers

Geologic conditions facilitate hydraulic connection between the Madison and Minnelusa aquifers. 

Confining layers in the lower portion of the Minnelusa 

Formation probably are influenced by paleokarst 

features such as caverns and sinkholes in the upper 

Madison Limestone. Extensive fracturing and solution 

activity have contributed to enhanced secondary 

porosity in both formations and decreased competency 

of the confining layers. Potential exists for downward 

leakage (from Minnelusa to Madison) in recharge areas 

where the aquifers are unconfined (water-table conditions), and for either upward or downward leakage, 

depending on direction of hydraulic gradient, where 

confined conditions exist. Hydraulic connections probably occur at various artesian springs, many of which 

discharge stratigraphically within or slightly above the 

Minnelusa Formation, but may include the Madison 

aquifer as a source (Whalen, 1994; Klemp, 1995; 

Hayes, 1999). Naus and others (2001) evaluated potential interactions through analysis of hydraulic and 

geochemical information for well pairs and artesian 

springs.

Hydrographs for Madison and Minnelusa well 

pairs were presented previously in figs. 26-29 and 

potential interactions were discussed in the section 

“Comparisons between Madison and Minnelusa aquifers.” Hydraulic connection for most colocated wells 

cannot be confirmed or refuted because aquifer testing 

has not been performed. Of the well pairs with generally similar hydrographs (fig. 27), hydraulic connection has been confirmed by aquifer testing (Greene, 

1993) only for the City Quarry wells (fig. 27D). These 

wells are located near City Springs, where aquifer connection has been confirmed by dye testing (Greene, 

1999). Aquifer testing (Greene and others, 1999) provided no indication of hydraulic connection in the 

vicinity of the Spearfish Golf Course wells (fig. 27A). 

Hydrographs for many other colocated wells indicate 

distinct hydraulic separation and no evidence of direct 

hydraulic connection between the aquifers.

Although some exchange of water must occur in 

locations where hydraulic head differences occur, Naus 

and others (2001) concluded from examination of 

geochemical information for colocated wells that general leakage between the Madison and Minnelusa 

aquifers probably does not result in areally extensive 

mixing in most locations. The most notable differences 

in ion chemistry (figs. 34 and 35) are in concentrations 

of sulfate, which increase with increasing distance 

from recharge areas in the Minnelusa aquifer but do not 

provide definitive information regarding aquifer 

mixing. Although δ18O values for samples from colocated Madison and Minnelusa wells (fig. 80) reflect 

generally higher recharge altitudes for the Madison 

aquifer than for the Minnelusa aquifer, information 

regarding aquifer mixing is inconclusive. Similarly, 

tritium concentrations for well pairs (fig. 81) do not 

provide conclusive information.

Substantial interactions between the Madison 

and Minnelusa aquifers can occur at artesian springs, 

many of which have large discharges. Combined discharge of all artesian springs within the Black Hills 

area of South Dakota and Wyoming was estimated by 

Driscoll and Carter (2001) as 169 ft3/s for 1950-98, 

which represents about 46 percent of average recharge 

to both aquifers (table 14). Numerous investigators 

have identified the Madison and Minnelusa aquifers as 

probable sources for artesian springs in the Black Hills, 

based on hydraulic properties and geochemical characteristics. The Minnekahta aquifer also may be a contributing source in locations where the Minnekahta 

Limestone is present. The underlying Deadwood 

aquifer also cannot be discounted as a possible source.

Locations of artesian springs are shown on the 

previously presented potentiometric-surface maps of 

the Madison and Minnelusa aquifers (figs. 19 and 20). 

Hydraulic heads in these aquifers at major spring locations were estimated from potentiometric-surface maps 

and are summarized in table 18, along with the approximate land-surface altitudes near the springs.

Several hydraulic possibilities exist for interactions between the Madison and Minnelusa aquifers at 

spring locations, including: (1) water originates only 

from the Minnelusa aquifer, with no contribution from 

the underlying Madison aquifer; (2) water originates 

entirely from the Madison aquifer and passes through 

the Minnelusa Formation, with little interaction; 

(3) water originates entirely from the Madison aquifer, 

part of which discharges at the surface and part of 

which recharges the Minnelusa aquifer; and (4) water 

originating from both aquifers contributes to springflow. For cases where the Madison aquifer contributes 

to springflow, leakage to the Minnelusa aquifer could 

consist of either focused leakage in the immediate 

vicinity of the spring-discharge point or general 

leakage in upgradient locations.
Madison and Minnelusa Flow System 141

Table 18. Selected hydraulic and geochemical information for major artesian springs 

[Modified from Naus and others (2001). ft3/s, cubic feet per second; mg/L, milligrams per liter; <, less than; ≈, approximately equal]

Name

Approximate

discharge

 (ft3/s)

Altitude

of land

surface

(feet above 

sea level)

Hydraulic head

(feet above sea level) Sulfate

(mg/L)

Estimated spring source from previous 

Madison studies

aquifer

Minnelusa

aquifer

Higgins Gulch 5-10 3,405 3,490 3,550 110 Mostly Madison1

Old Spearfish Hatchery ≈5 3,405 3,500 3,550 340 70 percent Madison, 30 percent Minnelusa1

NcNenny Rearing Pond ≈1 3,400 3,720 3,580 130 Mostly Madison1

Mirror Lake ≈1 3,410 3,720 3,580 1,600 50 percent Madison, 50 percent Minnelusa1

Cox Lake ≈5 3,415 3,705 3,580 545 Mostly Madison1

Crow Creek 30-50 3,355 3,710 3,560 580 --

Elk Creek 0-20 3,450 3,450 3,450 420 --

City Springs 0-5 3,440 3,450 3,450 98 --

Cleghorn Springs 20-25 3,380 3,420 3,380 25 --

Battle Creek 1-10 3,540 3,540 3,540 19 --

Grace Coolidge Creek 0-20 3,650 3,650 3,650 11 --

Beaver Creek Spring 10-15 3,460 3,480 3,480 1,300 Mostly Madison with dissolved

Minnelusa minerals2

Hot Brook Spring <5 3,625 3,700 3,625 76 Mostly Madison2

Evans Plunge Spring <5 3,465 3,610 3,420 540 Mostly Madison2

Fall River 20-30 3,415 3,580 3,360 400 --

Cool Spring ≈2 3,450 3,505 3,450 830 --

Cascade Spring 18-22 3,440 3,495 3,450 1,500 Mostly Madison with dissolved

Minnelusa minerals3

1

Estimated by Klemp (1995). 2Estimated by Whalen (1994).

3Estimated by Hayes (1999).

Precise quantification of relative contributions 

from source aquifers to individual springs is not necessarily possible; however, the Minnelusa aquifer probably can be discounted as a primary source for springs 

located where the Minnelusa Formation is exposed, 

which generally precludes confined conditions in the 

Minnelusa aquifer. This setting exists at Cleghorn/ 

Jackson Springs in western Rapid City and at Hot 

Brook Spring located just northwest of Hot Springs 

(fig. 20). Other artesian springs listed in table 18 occur 

in locations where the Minnelusa Formation is confined by overlying units and confined conditions are 

assumed for both the Madison and Minnelusa aquifers. 

Mapped hydraulic heads at most artesian spring 

locations are higher in the Madison aquifer than the 

Minnelusa aquifer (table 18, figs. 19 and 20), which 

could indicate higher potential for contributions to 

springflow from the Madison aquifer, relative to contributions from the Minnelusa aquifer. An alternative line 

of reasoning may be plausible, however. Higher 

hydraulic head in the Madison aquifer also indicates 

relatively competent confinement by the overlying 

Minnelusa Formation, which could imply larger contributions from the Minnelusa aquifer. Thus, generalities 

regarding dominant contributions to artesian springflow cannot be inferred from comparisons of hydraulic 

head.
142 Hydrology of the Black Hills Area, South Dakota

Discharge characteristics for artesian springs 

(table 18) probably are affected by hydraulic conditions at spring locations. Flow variability is minimal 

for many artesian springs (Miller and Driscoll, 1998; 

Anderson and others, 1999; U.S. Geological Survey, 

2000), including McNenny Rearing Pond, Cox Lake, 

Crow Creek, Cleghorn Springs, Beaver Creek Springs, 

Fall River, and Cascade Springs. Hydraulic heads at 

these sites generally are substantially above land surface for one or both of the two aquifers. In contrast, discharge is much more variable for Elk Creek, City 

Springs, Battle Creek, and Grace Coolidge Creek. At 

these sites, mapped hydraulic heads in both aquifers are 

approximately coincident with land-surface altitude.

Contributions from the Madison and Minnelusa 

aquifers to individual artesian springs cannot necessarily be quantified precisely (Naus and others, 2001) 

because of geochemical similarities between the aquifers (figs. 35 and 36). For some springs, high sulfate 

concentrations (table 18) could indicate Minnelusa 

influence, but may result from dissolution of 

Minnelusa minerals by water from the Madison 

aquifer. Previous investigators (Whalen, 1994; Klemp, 

1995; and Hayes, 1999) used geochemical modeling to 

estimate contributions of the Madison and Minnelusa 

aquifers to selected springs; generalized results are 

summarized in table 18. The Madison aquifer generally 

was identified as the primary source, with variable contributions from the Minnelusa aquifer, or chemical 

influences resulting from residence time within the 

Minnelusa Formation.

Saturation indices reported by Naus and others 

(2001) indicate that the Madison aquifer is undersaturated with respect to gypsum, even at the highest sulfate concentrations. Generally higher hydraulic head in 

the Madison aquifer, in combination with gypsum 

undersaturation, was concluded by Naus and others 

(2001) to be a primary mechanism driving interactions 

with the Minnelusa aquifer, in areas where confined 

conditions exist. Upward leakage from the Madison 

aquifer probably contributes to general dissolution of 

anhydrite deposits and development of breccia pipes in 

the Minnelusa aquifer. Breccia development may be 

especially prevalent in locations where the competency 

of intervening confining layers has been decreased by 

fracturing or by depositional influences in the Minnelusa Formation resulting from paleokarstification of 

the Madison Limestone.

Hayes (1999) hypothesized that upward leakage 

from the Madison aquifer was contributing to ongoing 

development of breccia pipes at Cascade Springs. 

Hayes (1999) noted that breccia pipes commonly occur 

in the upper Minnelusa Formation, but very few have 

been observed in the lower part of the formation. Networks of interbedded breccia layers and short, vertical 

breccia dikes do occur in the lower Minnelusa Formation, however, as schematically illustrated in figure 85.

Development of breccia pipes probably contributes to enhanced vertical hydraulic conductivity in the 

Minnelusa aquifer. Breccia pipes are a likely pathway 

for upward movement of large quantities of water 

through the Minnelusa aquifer at artesian spring locations. Dissolution processes are an important factor in 

a self-perpetuating process associated with development of preferential flowpaths and artesian springs. 

Preferential flowpaths initially develop in locations 

with large secondary porosity and associated hydraulic 

conductivity, with ongoing enhancement resulting 

from dissolution activity.

Hayes (1999) further hypothesized that many 

exposed breccia pipes of the upper Minnelusa Formation probably are the throats of abandoned artesian 

springs. An outward (downgradient) shifting of locations of artesian springs probably has occurred as 

upgradient spring-discharge points are abandoned and 

new ones are occupied, keeping pace with regional erosion over geologic time (Hayes, 1999). In response, 

hydraulic heads in the Madison and Minnelusa aquifers 

have declined over geologic time, as indicated by 

exposed breccia pipes located upgradient from Cascade 

Springs (Hayes, 1999). Further supporting evidence is 

provided by Ford and others (1993), who concluded 

that water-level declines of more than 300 ft have 

occurred in the Madison aquifer during the last 350,000 

years, based on geochemical data for Wind Cave.

Ground water discharging from the Madison 

aquifer at artesian springs was referred to as “rejected 

recharge” by Huntoon (1985), who hypothesized that 

recharge is rejected as transmissivity decreases with 

distance from upgradient recharge areas. This hypothesis is consistent with decreasing potential for large 

secondary porosity with increasing distance from the 

uplift, which results from: (1) decreased deformation 

and associated fracturing of rocks; and (2) decreasing 

potential for dissolution enhancement associated with 

increasing basinward concentrations of dissolved 

constituents.
Madison and Minnelusa Flow System 143

Artesian springs are essentially a “pressurerelief” mechanism that influence the upper limit for 

hydraulic head. As previously noted, springs located 

where hydraulic head is substantially above land surface generally have relatively stable discharge. In locations where hydraulic head is near land surface, 

however, discharge characteristics generally are more 

variable, with springflow increasing in response to 

increasing water levels.

Considering all available information, it was 

concluded by Naus and others (2001) that interactions 

between the Madison and Minnelusa aquifers are an 

important factor governing the hydraulic behavior of 

the two aquifers. The exchange of water resulting from 

general, areal leakage probably is small, relative to that 

which occurs near artesian springs; however, both processes probably contribute to the control of hydraulic 

heads in the Black Hills area. Interactions between the 

aquifers are an important consideration regarding the 

hydraulic behavior of the Madison and Minnelusa 

aquifer system, which has a major influence on the 

overall hydrology of the Black Hills area, as discussed 

in the following section.

Influence on Overall Hydrology of

Black Hills Area

The Madison and Minnelusa aquifers strongly 

influence the hydrology of the Black Hills area and 

have important water-management implications. The 

ground-water hydrology of the area is dominated by the 

Madison and Minnelusa aquifers, which receive about 

84 percent of estimated recharge to all bedrock aquifers 

in the study area. The Madison and Minnelusa aquifers 

are the most heavily used aquifers in the study area, 

with ongoing development occurring to meet steadily 

expanding needs for ground-water resources. Surfacewater resources, which also are heavily used in the 

Figure 85. Schematic showing breccia pipes and caves in relation to the hydrogeologic setting of the Black 

Hills area (modified from Hayes, 1999). Breccia pipes contribute to secondary porosity in the Madison and 

Minnelusa aquifers and may result from upward leakage from the Madison aquifer, creating conduits for 

artesian springs. Arrows show general areal leakage and focused leakage at breccia pipes.

Potentiometric surface

of Madison aquifer

Alluvium

Dip of sedimentary rocks exaggerated

Precambrian metamorphic

and igneous rocks

Deadwood

Inyan Kara Group

Thicknesses not to scale

Madison Limestone

Minnelusa

Minnekahta

Limestone

CAVE

BRECCIA PIPE

CONFINING UNIT

EXPLANATION

Formation

Formation

Water

table

Artesian spring

OTHER AQUIFER

MADISON AND MINNELUSA

 AQUIFERS
144 Hydrology of the Black Hills Area, South Dakota

study area, are influenced by interactions with these 

aquifers.

Headwater springflow, which originates primarily from the Madison and Minnelusa aquifers in the 

Limestone Plateau area, provides a reliable source of 

baseflow in several streams. Relatively stable discharge is an important characteristic of the limestone 

headwater springs, which generally are influenced primarily by long-term, rather than short-term, climatic 

conditions. Thus, adequate baseflow for sustaining 

aquatic populations often can be maintained during 

extended periods of dry conditions in streams with substantial influence from headwater springflow. A general absence of direct runoff is another distinguishing 

characteristic of areas with extensive outcrops of the 

Madison Limestone and Minnelusa Formation.

Streamflow losses that provide recharge to the 

Madison and Minnelusa aquifers are another important 

influence on the hydrology of the Black Hills area. 

Only two streams in the study area maintain perennial 

flow through loss zones—Whitewood Creek, in which 

the loss zone probably has been sealed by mine tailings 

(Hortness and Driscoll, 1998), and Rapid Creek. 

Spearfish Creek also would maintain perennial flow 

under natural conditions; however, flow is diverted 

around the loss zone for hydroelectric power generation. Utilization of surface- and ground-water 

resources upstream from loss zones has potential to 

reduce recharge to the Madison and Minnelusa aquifers. In some streams, discharge of limestone headwater springs can provide a relatively consistent source 

of streamflow for subsequent recharge in loss zones.

Streamflow loss zones create potential for direct 

introduction of contaminants into the Madison and 

Minnelusa aquifers, which can have small filtration 

capacity and large potential for rapid transport of contaminants because of large secondary permeability. 

Similar concerns exist for all recharge areas of these 

aquifers, regardless of proximity to streamflow loss 

zones. The Madison and Minnelusa aquifers are among 

the most sensitive of all hydrogeologic units in the 

study area, relative to contamination potential (Davis 

and others, 1994; Putnam, 2000).

Artesian springflow from the Madison and 

Minnelusa aquifers is an especially important influence 

on surface-water resources in the study area. Artesian 

springflow provides large and consistent baseflow for 

many streams in exterior areas, where zero-flow conditions commonly occur in streams that are not influenced by artesian springs. This baseflow is especially 

important in maintaining adequate flow for aquatic 

populations and for various water-supply needs 

including stock water, municipal supply, and irrigation. 

In many locations irrigation withdrawals are made 

directly from streams. In addition, artesian springs provide large and consistent baseflow upstream from 

Angostura and Belle Fourche Reservoirs, which also 

are heavily used for recreational purposes.

As previously mentioned, artesian springs are 

essentially a pressure-relief mechanism that influence 

the upper limit for hydraulic head in the Madison and 

Minnelusa aquifers. These aquifers have a “maximumsustainable equilibrium” water level, which is controlled by the discharge of artesian springs, with springflow increasing in response to increasing recharge and 

water levels. Conversely, artesian springflow decreases 

in response to decreasing water levels. As discussed 

previously, hydraulic heads are approximately coincident with land-surface altitudes near some artesian 

springs (table 18). Thus, large-scale well withdrawals 

near some artesian springs could diminish springflow 

before large-scale declines in water levels would occur. 

However, to some extent, the large recharge potential 

of the Madison and Minnelusa aquifers may be sufficient to replenish springflow and water levels relatively 

quickly during episodic periods of prolonged wet conditions.

Additional insights regarding potential effects of 

large-scale development of the Madison and Minnelusa 

aquifers can be obtained by reviewing the water budget 

for these aquifers for the entire Black Hills area 

(including both South Dakota and Wyoming) that was 

presented previously in table 14. For this budget, the 

dominant outflow component is artesian springflow of 

169 ft3/s, which is larger than combined well withdrawals (28 ft3/s) and ground-water outflow from the 

study area (100 ft3/s). Hypothetically, artesian springflow could be replaced by increased well withdrawals 

without causing substantial changes in hydraulic 

gradient or associated ground-water outflow from the 

study area (figs. 69 and 70).

The previous interpretations could provide 

insights regarding future management of ground-water 

resources and potential influences on surface-water 

resources. Many large springs currently have relatively 

stable discharge, whereas others, including both small 

and large springs, have large variability in discharge 

characteristics. Large-scale development of the 

Madison and Minnelusa aquifers probably has the 

potential to influence the balance of this dynamic 
References 145

“plumbing system.” Potential effects would be most 

pronounced during prolonged drought periods, which 

would result in decreased recharge and increased 

demand. Although discharges of many artesian springs 

respond slowly to changes in recharge conditions (both 

decreases and increases), other springs respond more 

quickly. Similarly, responses to large-scale increases in 

well withdrawals probably would be distinct for particular withdrawal scenarios.

REFERENCES

Amundson, F.D., 1998, Estimated use of water in South 

Dakota, 1995: U.S. Geological Survey Open-File 

Report 98-268, 18 p.

Anderson, M.T., Driscoll, D.G., and Williamson, J.E., 1999, 

Ground-water and surface-water interactions along 

Rapid Creek near Rapid City, South Dakota: U.S. 

Geological Survey Water-Resources Investigations 

Report 98-4214, 99 p.

Anna, L.O., 1986, Geologic framework of the ground-water 

system in Jurassic and Cretaceous rocks in the northern 

Great Plains, in parts of Montana, North Dakota, South 

Dakota, and Wyoming: U.S. Geological Survey Professional Paper 1402-B, 36 p.

Back, W., Hanshaw, B.B., Plummer, L.N., Rahn, P.H., Rightmire, C.T., and Rubin, M., 1983, Process and rate of 

dedolomitization: Mass transfer and 14C dating in a 

regional carbonate aquifer: Geological Society of 

America Bulletin, v. 94, no. 12, p. 1415-1429.

Bartlett and West Engineers, Inc., 1998, Piedmont Valley 

water quality assessment study—Final report: Bismarck, N. Dak., Bartlett and West Engineers, Inc. 

[variously paged].

Blankennagel, R.K., Howells, L.W., and Miller, W.R., 1981, 

Completion and testing of Madison Limestone test well 

3, NW 1/4 SE 1/4, sec. 35, T. 2N., R. 27E., Yellowstone 

County, Montana: U.S. Geological Survey Open-File 

Report 81-528, 91 p.

Blankennagel, R.K., Miller, W.R., Brown, D.L., and Cushing, E.M., 1977, Report on preliminary data for Madison Limestone test well 1, NE 1/4 SE 1/4 sec. 15, T. 

57N., R. 65W., Crook County, Wyoming: U.S. Geological Survey Open-File Report 77-164, 97 p., 3 plates.

Boggs, J.M., and Jenkins, A.M., 1980, Analysis of aquifer 

tests conducted at the proposed Burdock Uranium Mine 

Site, Burdock, South Dakota: Norris, Tenn., Tennessee 

Valley Authority, Office of Natural Resources, Division 

of Natural Resources, Water System Development 

Branch, Report No. WR28-1-520-109, 73 p.

Braddock, W.A., 1963, Geology of the Jewel Cave SW 

Quadrangle, Custer County, South Dakota: U.S. 

Geological Survey Bulletin 1063-G, p. 217-268.

Bredehoeft, J.D., Neuzil, C.E., and Milly, P.C.D., 1983, 

Regional flow in the Dakota aquifer—A study of the 

role of confining layers: U.S. Geological Survey 

Water-Supply Paper 2237, 45 p.

Brown, C.B., 1944, Report on an investigation of water 

losses in streams flowing east out of the Black Hills, 

South Dakota: U.S. Soil Conservation Service, Special 

Report 8, 45 p.

Bureau of Reclamation, 1999, Annual operating plans, 

Upper Missouri River Basin: Billings, Mont. (issued 

annually).

Busby, J.F., Kimball, B.A., Downey, J.S., and Peter, K.D., 

1995, Geochemistry of water in aquifers and confining 

units of the northern Great Plains in parts of Montana, 

North Dakota, South Dakota, and Wyoming: U.S. 

Geological Survey Professional Paper 1402-F, 146 p.

Busby, J.F., Lee, R., and Hanshaw, B.B., 1983, Major 

geochemical processes related to the hydrology of the 

Madison aquifer system and associated rocks in parts of 

Montana, South Dakota, and Wyoming: U.S. Geological Survey Water-Resources Investigation Report 

83-4093, 180 p.

Busby, J.F., Plummer, L.N., Lee, R.W., and Hanshaw, B.B., 

1991, Geochemical evolution of water in the Madison 

aquifer in parts of Montana, South Dakota, and Wyoming: U.S. Geological Survey Professional Paper 

1273-F, 89 p.

Callahan, M.A., Slimak, M.W., Gabel, N.W., May, I.P., 

Fowler, C.F., Freed, J.R., Jennings, Patricia, Durfee, 

R.L., Whitmore, F.C., Maestri, Bruno, Mabey, W.R., 

Holt, B.R., and Gould, Constance, 1979, Water-related 

environmental fate of 129 priority pollutants, Volume 

I—Introduction and technical background, metals and 

inorganics, pesticides and PCBs: U.S. Environmental 

Protection Agency, Office of Water Planning and Standards, Office of Water and Waste Management, EPA440/4-79-029a [variously paged]. 

Carlson, C.G., and Anderson, S.B., 1965, Sedimentary and 

tectonic history of North Dakota part of Williston 

Basin: Bulletin of the American Association of Petroleum Geologists, v. 49, no. 11, p. 1833-1846.

Carter, J.M, Driscoll, D.G., and Hamade, G.R., 2001, Estimated recharge to the Madison and Minnelusa aquifers 

in the Black Hills area, South Dakota: U.S. Geological 

Survey Water-Resources Investigations Report 00-

4278, 66 p.

Carter, J.M., Driscoll, D.G., Hamade, G.R., and Jarrell, G.J., 

2001, Hydrologic budgets for the Madison and Minnelusa aquifers in the Black Hills of South Dakota and 

Wyoming, water years 1987-96: U.S. Geological Survey Water-Resources Investigations Report 01-4119, 

53 p.
146 Hydrology of the Black Hills Area, South Dakota

Carter, J.M. and Redden, J.A., 1999a, Altitude of the top of 

the Inyan Kara Group in the Black Hills area, South 

Dakota: U.S. Geological Survey Hydrologic Investigations Atlas HA-744-A, 2 sheets, scale 1:100,000.

———1999b, Altitude of the top of the Minnekahta Limestone in the Black Hills area, South Dakota: U.S. 

Geological Survey Hydrologic Investigations Atlas 

HA-744-B, 2 sheets, scale 1:100,000.

———1999c, Altitude of the top of the Minnelusa Formation in the Black Hills area, South Dakota: U.S. 

Geological Survey Hydrologic Investigations Atlas 

HA-744-C, 2 sheets, scale 1:100,000.

———1999d, Altitude of the top of the Madison Limestone 

in the Black Hills area, South Dakota: U.S. Geological 

Survey Hydrologic Investigations Atlas HA-744-D, 

2 sheets, scale 1:100,000.

———1999e, Altitude of the top of the Deadwood Formation in the Black Hills area, South Dakota: U.S. 

Geological Survey Hydrologic Investigations Atlas 

HA-744-E, 2 sheets, scale 1:100,000.

Clark, I.D., and Fritz, P., 1997, Environmental isotopes in 

hydrogeology: Boca Raton, Fla., Lewis Publishers, 

328 p.

Clawges, R.M., 2000a, Digital map of saturated thickness of 

the Madison aquifer, Black Hills, South Dakota: U.S. 

Geological Survey data available on the World Wide 

Web, accessed July 2, 2001, at URL 

http://water.usgs.gov/lookup/getspatial?sd_mdsnst_thk

———2000b, Digital map of saturated thickness of the 

Minnelusa aquifer, Black Hills, South Dakota: U.S. 

Geological Survey data available on the World Wide 

Web, accessed July 2, 2001, at URL 

http://water.usgs.gov/lookup/getspatial?sd_mnlsst_thk

Cooley, R.L., Konikow, L.F., and Naff, R.L., 1986, Nonlinear-regression groundwater flow modeling of a deep 

regional aquifer system: Water Resources Research, 

v. 22, no. 13, p. 1759-1778.

Craig, H., 1961, Isotopic variations in meteoric waters: 

Science, v. 133, p. 1702-1703.

Darton, N.H., and Paige, Sidney, 1925, Central Black Hills 

[quadrangle], South Dakota: U.S. Geological Survey 

Atlas of the United States, Folio 219, 34 p.

Davis, A.D., Long A.J., Nazir, M., and Tan, X., 1994, 

Ground-water vulnerability in the Rapid Creek Basin 

above Rapid City, South Dakota—Final Technical 

Report: Denver, Colo., U.S. Environmental Protection 

Agency, Region VIII Office, Contract X008788-01-0, 

78 p.

DeWitt, Ed, Redden, J.A., Buscher, David, and Wilson, 

A.B., 1989, Geologic map of the Black Hills area, 

South Dakota and Wyoming: U.S. Geological Survey 

Map I-1910, scale 1:250,000.

DeWitt, Ed, Redden, J.A., Wilson, A.B., and Buscher, 

David, 1986, Mineral resource potential and geology of 

the Black Hills Nations Forest, South Dakota and Wyoming: U.S. Geological Survey Bulletin 1580, 135 p.

Downey, J.S., 1984, Geohydrology of the Madison and associated aquifers in parts of Montana, North Dakota, 

South Dakota, and Wyoming: U.S. Geological Survey 

Professional Paper 1273-G, 47 p.

———1986, Geohydrology of bedrock aquifers in the 

northern Great Plains in parts of Montana, North 

Dakota, South Dakota, and Wyoming: U.S. Geological 

Survey Professional Paper 1402-E, 87 p.

Downey, J.S., and Dinwiddie, G.A., 1988, The regional 

aquifer system underlying the northern Great Plains in 

parts of Montana, North Dakota, South Dakota, and 

Wyoming—Summary: U.S. Geological Survey Professional Paper 1402-A, 64 p.

Driscoll, D.G., 1992, Plan of study for the Black Hills 

Hydrology Study, South Dakota: U.S. Geological 

Survey Open-File Report 92-84, 10 p.

Driscoll, D.G., Bradford, W.L., and Moran, M.J., 2000, 

Selected hydrologic data, through water year 1998, 

Black Hills Hydrology Study, South Dakota: U.S. 

Geological Survey Open-File Report 00-70, 284 p.

Driscoll, D.G., and Carter J.M., 2001, Hydrologic conditions 

and budgets in the Black Hills area of South Dakota, 

through water year 1998: U.S. Geological Survey 

Water-Resources Investigations Report 01-4226, 143 p.

Driscoll, D.G., Hamade, G.R., and Kenner, S.J., 2000, Summary of precipitation data compiled for the Black Hills 

area of South Dakota, water years 1931-98: U.S. 

Geological Survey Open-File Report 00-329, 151 p.

Driscoll, D.G., and Hayes, T.S., 1995, Arsenic loads in 

Spearfish Creek, western South Dakota, water years 

1989-91: U.S. Geological Survey Open-File Report 

91-249, 194 p.

Durkin, T.V., 1996, Acid Mine Drainage—Reclamation at 

the Richmond Hill and Gilt Edge Mines, South Dakota 

in U.S. Environmental Protection Agency, Managing 

environmental problems at inactive and abandoned 

metals mine sites: U.S. Environmental Protection 

Agency Seminar Publication No. EPA/625/R-95/007, 

p 54-61. 

Ford, D.C., Lundberg, J., Palmer, A.N., Palmer, M.V., Dreybrodt, W., and Schwarcz, H.P., 1993, Uranium-series 

dating of the draining of an aquifer—The example of 

Wind Cave, Black Hills, South Dakota: Geological 

Society of America Bulletin, v. 105, p. 241-250.

Fuller, C.C., and Davis, J.A., 1989, Influence of coupling of 

sorption and photosynthetic processes on trace element 

cycles in natural water: Nature, v. 340, p. 52-54.

Fuller, C.C., Davis, J.A., and Waychunas, G.A., 1993, Surface chemistry of ferrihydrite; Part 2, Kinetics of arsenate adsorption and coprecipitation: Geochimica et 

Cosmochimica Acta, v. 57, no. 10, p. 2271-2282.
References 147

Galloway, J.M., and Strobel, M.L., 2000, Hydrologic characteristics of metamorphic and igneous rocks in the central core of the Black Hills, South Dakota [abs.], in

Strobel, M.L., and others, eds., Proceedings of the 

Hydrology of the Black Hills Conference, South 

Dakota School of Mines Bulletin 20, p. 87.

Goddard, K.E., 1989, Composition, distribution, and hydrologic effects of contaminated sediments resulting from 

the discharge of gold milling wastes to Whitewood 

Creek at Lead and Deadwood, South Dakota: U.S. 

Geological Survey Water-Resources Investigations 

Report 87-4051, 76 p.

Goddard, K.E., Lockner, T.K., Harms, L.L., and Smith, 

M.H., 1989, Summary of data pertaining to land use, 

rainfall, dryfall, stream discharge, and storm runoff collected as part of a study of the effects of urban runoff on 

Rapid Creek, Rapid City area, South Dakota: U.S. 

Geological Survey Open-File Report 87-45, 194 p.

Gott, G.B., Wolcott, D.E., and Bowles, C.G., 1974, Stratigraphy of the Inyan Kara Group and localization of uranium deposits, southern Black Hills, South Dakota and 

Wyoming: U.S. Geological Survey Professional Paper 

763, 57 p.

Greene, E.A., 1993, Hydraulic properties of the Madison 

aquifer system in the western Rapid City area, South 

Dakota: U.S. Geological Survey Water-Resources 

Investigations Report 93-4008, 56 p.

———1997, Tracing recharge from sinking streams over 

spatial dimensions of kilometers in a karst aquifer: 

Ground Water, v. 35, no. 5, p. 898-904.

———1999, Characterizing recharge to wells in carbonate 

aquifers using environmental and artificially recharged 

tracers, in Morganwalp, D.W., and Buxton, H.T., eds., 

U.S. Geological Survey Toxic Substances Hydrology 

Program—Proceedings of the Technical Meeting, 

Charleston, South Carolina, March 8-12, 

1999—Volume 3 of 3—Subsurface Contamination 

from Point Sources: U.S. Geological Survey WaterResources Investigations Report 99-4018C, p. 803-

808.

Greene, E.A., and Rahn, P.H., 1995, Localized anisotropy in 

a karst aquifer: Ground Water, v. 33, no. 5, p. 806-816.

Greene, E.A., Shapiro, A.M., and Carter, J.M., 1999, Hydrogeologic characterization of the Minnelusa and Madison aquifers near Spearfish, South Dakota: U.S. 

Geological Survey Water-Resources Investigations 

Report 98-4156, 64 p.

Greene, E.A., Sowards, C.L., and Hansmann, E.W., 1990, 

Reconnaissance investigation of water quality, bottom 

sediment, and biota associated with irrigation drainage 

in the Angostura Reclamation Unit, southwestern South 

Dakota, 1988-89: U.S. Geological Survey WaterResources Investigations Report 90-4152, 75 p.

Gries, J.P., 1975, Mineral and water resources of South 

Dakota: U.S. Congress, 94th, 1st Session, Interior and 

Insular Affairs Committee Print, 313 p.

———1996, Roadside geology of South Dakota: Missoula, 

Mont., Mountain Press Publishing Company, 358 p.

Gries, J.P., Rahn, P.H., and Baker, R.K., 1976, A pump test 

in the Dakota Sandstone at Wall, South Dakota: South 

Dakota Geological Survey Circular 43, 9 p.

Harms, L.L, Smith, Marsha, and Goddard, Kim, 1983, Urban 

runoff control in Rapid City, South Dakota: Rapid City, 

S. Dak., Black Hills Council of Local Governments, 

21 p.

Hayes, T.S., 1999, Episodic sediment-discharge events in 

Cascade Springs, southern Black Hills, South Dakota: 

U.S. Geological Survey Water-Resources Investigations Report 99-4168, 34 p.

Heath, R.C., 1983, Basic ground-water hydrology: U.S. 

Geological Survey Water-Supply Paper 2220, 84 p.

Hem, J.D., 1985, Study and interpretation of chemical characteristics of natural water (3d ed.): U.S. Geological 

Survey Water-Supply Paper 2254, 263 p.

Hortness, J.E., and Driscoll, D.G., 1998, Streamflow losses 

in the Black Hills of western South Dakota: U.S. 

Geological Survey Water-Resources Investigations 

Report 98-4116, 99 p.

Huntoon, P.W., 1985, Rejection of recharge water from 

Madison aquifer along eastern perimeter of Bighorn 

Artesian Basin, Wyoming: Ground Water, v. 23, no. 3, 

p. 345-353.

Imam, Mozaffer, 1991, Factors affecting the yield of 

Madison wells in the Black Hills: Rapid City, South 

Dakota School of Mines and Technology, unpublished 

M.S. thesis, 96 p.

International Atomic Energy Agency, 1981, Statistical treatment of environmental isotope data in precipitation: 

Technical Report Series No. 206, 256 p.

Jarrell, G.J., 2000, Delineation of ground-water basins on the 

Limestone Plateau, Black Hills, South Dakota: Rapid 

City, South Dakota School of Mines and Technology, 

unpublished M.S. thesis, 68 p.

Johnson, B.N., 1933, A climatological review of the Black 

Hills: The Black Hills Engineer, Rapid City, South 

Dakota School of Mines and Technology, 71 p.

Klemp, J.A., 1995, Source aquifers for large springs in 

northwestern Lawrence County, South Dakota: Rapid 

City, South Dakota School of Mines and Technology, 

unpublished M.S. thesis, 175 p.

Koch, N.C., 1983, Irrigation-water classification diagram for 

South Dakota: South Dakota Academy of Science 

Proceedings, v. 62, p. 107-114.

Konikow, L.F., 1976, Preliminary digital model of groundwater flow in the Madison Group, Powder River Basin 

and adjacent areas, Wyoming, Montana, South Dakota, 

North Dakota, and Nebraska: U.S. Geological Survey 

Water-Resources Investigations Report 63-75, 44 p., 

6 plates.
148 Hydrology of the Black Hills Area, South Dakota

Kyllonen, D. P., and Peter, K.D., 1987, Geohydrology and 

water quality of the Inyan Kara, Minnelusa, and 

Madison aquifers of the northern Black Hills, South 

Dakota and Wyoming, and Bear Lodge Mountains, 

Wyoming: U.S. Geological Survey Water-Resources 

Investigations Report 86-4158, 61 p.

Long, A.J., 2000, Modeling techniques for karst aquifers—anisotropy, dual porosity, and linear systems 

analysis: Rapid City, South Dakota School of Mines 

and Technology, unpublished Ph.D. dissertation, 59 p.

Luza, K.V., 1969, Origin, distribution, and development of 

bog iron in the Rochford District, north-central Black 

Hills, South Dakota: Rapid City, South Dakota School 

of Mines and Technology, unpublished M.S. thesis, 

159 p.

Michel, R.L., 1989, Tritium deposition in the continental 

United States, 1953-83: U.S. Geological Survey WaterResources Investigations Report 89-4072, 46 p.

Miller, L.D., and Driscoll, D.G., 1998, Streamflow characteristics for the Black Hills of South Dakota, through 

water year 1993: U.S. Geological Survey WaterResources Investigations Report 97-4288, 322 p.

Miller, R.H., and Rahn, P.H., 1974, Recharge to the Dakota 

Sandstone from outcrops in the Black Hills, South 

Dakota: Bulletin of the Association of Engineering 

Geologists, v. 11, no. 3, p. 221-234.

Miller, W.R., 1976, Water in carbonate rocks of the Madison 

Group in southeastern Montana; a preliminary evaluation: U.S. Geological Survey Water-Supply Paper 

2043, 51 p.

National Oceanic and Atmospheric Administration, 1998, 

Climatological data for South Dakota, annual summary: Asheville, N.C., U.S. Department of Commerce 

(issued annually).

Naus, C.A., Driscoll, D.G., and Carter, J.M., 2001, 

Geochemistry of the Madison and Minnelusa aquifers 

in the Black Hills area, South Dakota: U.S. Geological 

Survey Water-Resources Investigations Report 01-

4129, 118 p.

Newton, Henry, and Jenney, W.P., 1880, Report of the geology and resources of the Black Hills of Dakota: Washington, D.C., Government Printing Office, 566 p.

Niven, D.W., 1967, Determination of porosity and permeability of selected sandstone aquifers of South Dakota: 

Rapid City, South Dakota School of Mines and Technology, unpublished M.S. thesis, 31 p.

Orr, H.K., 1959, Precipitation and streamflow in the Black 

Hills: U.S. Department of Agriculture, Forest Service, 

Rocky Mountain Forest and Range Experiment Station 

Paper No. 44, 25 p.

Pakkong, Mongkol, 1979, Ground water of the Boulder Park 

area, Lawrence County, South Dakota: Rapid City, 

South Dakota School of Mines and Technology, unpublished M.S. thesis, 91 p., 4 pl.

Peter, K.D., 1985, Availability and quality of water from the 

bedrock aquifers in the Rapid City area, South Dakota: 

U.S. Geological Survey Water-Resources Investigations Report 85-4022, 34 p.

Peterlin, J.D., 1990, Thermal springs and flow declines of 

the all River in the southern Black Hills of South 

Dakota: Rapid City, South Dakota School of Mines and 

Technology, unpublished M.S. thesis, 83 p.

Peterson, J.A. 1981, Stratigraphy and sedimentary facies of 

the Madison Limestone and associated rocks in parts of 

Montana, North Dakota, South Dakota, Wyoming, and 

Nebraska: U.S. Geological Survey Open-File Report 

81-642, 92 p.

Plummer, L.N., Busby, J.F., Lee, R.W., and Hanshaw, B.B., 

1990, Geochemical modeling of the Madison aquifer in 

parts of Montana, Wyoming, and South Dakota: Water 

Resources Research, v. 26, no. 9, p. 1981-2014.

Putnam, L.D., 2000, Sensitivity of ground water to contamination in Lawrence County, South Dakota: U.S. 

Geological Survey Water-Resources Investigations 

Report 00-4103, 55 p.

Rahn, P.H., 1985, Ground water stored in the rocks of western South Dakota in Rich, F.J., ed., Geology of the 

Black Hills, South Dakota and Wyoming (2d ed.): 

Geological Society of America, Field Trip Guidebook, 

American Geological Institute, p. 154-174.

Rahn, P.H., Davis, A.D., Webb, C.J., and Nichols, A.D., 

1996, Water quality impacts from mining in the Black 

Hills, South Dakota, USA: Environmental Geology, 

v. 27, p. 38-53.

Rahn, P.H., and Gries, J.P., 1973, Large springs in the Black 

Hills, South Dakota and Wyoming: South Dakota 

Geological Survey Report of Investigations 107, 46 p.

Redden, J.A., and Lisenbee, A.L., 1996, Geologic setting, 

Black Hills, South Dakota in Paterson, C.J., and Kirchner, J.G., eds., Guidebook to the geology of the Black 

Hills, South Dakota: Rapid City, South Dakota, South 

Dakota School of Mines and Technology Bulletin No. 

19, p. 1-8.

Rice, L.R., 1970, The treatment of iron and acid stream contamination in the Black Hills of South Dakota: Rapid 

City, South Dakota School of Mines and Technology, 

unpublished M.S. thesis, 212 p.

Roddy, W.R., Greene, E.A., and Sowards, C.L., 1991, 

Reconnaissance investigation of water quality, bottom 

sediment, and biota associated with irrigation drainage 

in the Belle Fourche Reclamation Project, western 

South Dakota: U.S. Geological Survey WaterResources Investigations Report 90-4192, 113 p.

Rounds, D.D., 1991, A reconnaissance-level investigation of 

selected radionuclides and water-quality characteristics 

of wells penetrating the Deadwood Formation, Black 

Hills, South Dakota: Rapid City, South Dakota School 

of Mines and Technology, unpublished M.S. thesis, 

94 p.
References 149

Sandberg, C.A., and Poole, F.G., 1977, Conodont biostratigraphy and depositional complexes of Upper Devonian 

cratonic-platform and continental shelf rocks in the 

western United States, in Murphy, M.A., Berry, 

W.B.N., and Sandberg, C.A., eds., Western North 

America—Devonian: University of California at 

Riverside, Museum Contributions 4, p. 144-182.

Sando, S.K., Williamson, J.E., Dickerson, K.K., and Wesolowski, E.A., 2001, Irrigation drainage studies of the 

Angostura Reclamation Unit and the Belle Fourche 

Reclamation Project, western South Dakota—Results 

of 1994 sampling and comparisons with 1988 data: 

U.S. Geological Survey Water-Resources Investigations Report 01-4103, 65 p.

South Dakota Department of Environment and Natural 

Resources, 1998, Summary of the mining industry in 

South Dakota: Minerals and Mining Program, South 

Dakota Department of Environment and Natural 

Resources, retrieved Dec. 28, 2000, from URL 

http://www.state.sd.us/denr/DES/mining/ 

1998minesum.htm

———2001a, Surface water quality—Administrative rules 

of South Dakota, 74:51: South Dakota Department of 

Environment and Natural Resources, accessed June 18, 

2001, at URL 

http://legis.state.sd.us/rules/rules/7451.htm

———2001b, Summary of the mining industry in South 

Dakota, 2000: Minerals and Mining Program, South 

Dakota Department of Environment and Natural 

Resources, retrieved July 10, 2001, from URL 

http://www.state.sd.us/denr/DES/Mining/ 

Goldrpta3.pdf

Stiff, H.A., Jr., 1951, The interpretation of chemical water 

analysis by means of patterns: Journal of Petroleum 

Technology, v. 3, no. 10, p. 15-17.

Strobel, M.L., Galloway, J.M., Hamade, G.R., and Jarrell, 

G.J., 2000a, Potentiometric surface of the Madison 

aquifer in the Black Hills area, South Dakota: U.S. 

Geological Survey Hydrologic Investigations Atlas 

HA-745-D, 2 sheets, scale 1:100,000.

———2000b, Potentiometric surface of the Minnelusa aquifer in the Black Hills area, South Dakota: U.S. Geological Survey Hydrologic Investigations Atlas HA745-C, 2 sheets, scale 1:100,000.

Strobel, M.L., Jarrell, G.J., Sawyer, J.F., Schleicher, J.R., and 

Fahrenbach, M.D., 1999, Distribution of hydrogeologic 

units in the Black Hills area, South Dakota: U.S. 

Geological Survey Hydrologic Investigations Atlas 

HA-743, 3 sheets, scale 1:100,000.

Swenson, F.A., 1968, New theory of recharge to the artesian 

basin of the Dakotas: Geological Society of America 

Bulletin 1081-B, p. 163-182. 

Tan, Xiaodan, 1994, Potentiometric surfaces, recharge rates, 

and hydraulic conductivities of the Madison and 

Minnelusa aquifers in the Rapid Creek basin above 

Rapid City, South Dakota: Rapid City, South Dakota 

School of Mines and Technology, unpublished M.S. 

thesis, 74 p.

Torve, K.C., 1991, Reconnaissance water-quality investigation of bed material, surface water, and ground water of 

select tributaries draining the mineralized region of 

Lawrence County near Lead, South Dakota: Rapid City, 

South Dakota School of Mines and Technology, unpublished M.S. thesis, 109 p.

Tweto, Ogden, 1975, Laramide (Late Cretaceous-early 

Tertiary) orogeny in the southern Rocky Mountains, in

Curtis, B.F., ed., Cenozoic history of the southern 

Rocky Mountains: Geological Society of America 

Memoir 144, p. 1-44.

U.S. Department of Commerce, 1999, Climatological data 

for South Dakota, annual summary: Asheville, North 

Carolina (issued annually).

U.S. Department of Interior, 1967, Black Hills area resources 

study: Washington, D.C., February 1967, 225 p.

U.S. Environmental Protection Agency, 1986, Quality criteria for water (updated May 1986), Update No. 2: Washington, D.C., Office of Water Regulations and 

Standards, EPA 440/5/-86-001, 398 p.

———1991, Lead and copper role fact sheet: U.S. Environmental Protection Agency, Office of Water, EPA 570/9-

91-400, 2 p.

———1994a, Summary of EPA finalized National primary 

drinking water regulations: U.S. Environmental Protection Agency Region VIII, 7 p.

———1994b, National primary drinking water standards: 

U.S. Environmental Protection Agency, Office of 

Water, EPA 810-F-94-001A, 4 p.

———1997, National primary drinking water regulations, 

Code of Federal regulations 40, parts 141 and 143, 

revised July 1, 1997, p. 288-476.

———2001, EPA to implement 10 ppb standard for arsenic 

in drinking water: U.S. Environmental Protection 

Agency, Office of Water, EPA 815-F-01-010, 2 p.

U.S. Geological Survey, 1999, The quality of our Nation’s 

waters—Nutrients and pesticides: U.S. Geological 

Survey Circular 1225, 82 p.

———2000, Water resources data, South Dakota, water 

year 1999: U.S. Geological Survey Water-Data Report 

SD-99-1, 501 p.

Wahl, K.L., and Wahl, T.L., 1995, Determining the flow of 

Comal Springs at New Braunfels, Texas: Proceedings 

of Texas Water ‘95, A Component Conference of the 

First International Conference on Water Resources 

Engineering, American Society of Civil Engineers, 

August 16-17, 1995, San Antonio, Texas, p. 77-86.

Whalen, P.J., 1994, Source aquifers for Cascade Springs, Hot 

Springs, and Beaver Creek Springs in the southern 

Black Hills of South Dakota: Rapid City, South Dakota 

School of Mines and Technology, unpublished M.S. 

thesis, 299 p.
150 Hydrology of the Black Hills Area, South Dakota

Whitehead, R.L., 1996, Ground water atlas of the United 

States—Segment 8, Montana, North Dakota, South 

Dakota, Wyoming: U.S. Geological Survey Hydrologic Investigations Atlas 730-I, 24 p.

Williamson, J.E., and Carter, J.M., 2001, Water-quality characteristics for the Black Hills area, South Dakota: U.S. 

Geological Survey Water-Resources Investigations 

Report 01-4194, 196 p.

Williamson, J.E., Goldstein, R.M., and Porter, S.D., 1996, 

Selected trace metals in water, sediment, plants, and 

fish in Rapid Creek, Rapid City, South Dakota: U.S. 

Geological Survey Water-Resources Investigations 

Report 96-4276, 30 p.

Williamson, J.E., and Hayes, T.S., 2000, Water-quality characteristics for selected streams in Lawrence County, 

South Dakota, 1988-92: U.S. Geological Survey 

Water-Resources Investigations Report 00-4220, 131 p.

Williamson, J.E., Jarrell, G.J., Clawges, R.M., Galloway, 

J.M., and Carter, J.M., 2000, Digital data sets for map 

products produced as part of the Black Hills Hydrology 

Study, western South Dakota: U.S. Geological Survey 

Open-File Report 00-471.

Woodward-Clyde Consultants, 1980, Well-field hydrology 

technical report for the Energy Transportation Systems 

Incorporated Coal Slurry Pipeline Project: WoodwardClyde Consultants, prepared for the U.S. Bureau of 

Land Management [variously paged].