SOILS APPENDIX

SOILS APPENDIX

SOI-1

SOILS APPENDIX

The U.S. Department of Agriculture’s (USDA) Natural 

Resources Conservation Services (NRCS) has 

published a general soil association map for Montana 

in digital format. The State Soil Geographic Database 

(STATSGO) (USDA NRCS 1996) provides a general 

overview of soils distribution and occurrences in the 

planning area, at a 1:250,000 scale and is not suitable 

for site-specific evaluations. More detailed information 

is available from Soil Survey Geographic Databases 

(SSURGO) at 

http://www.ncgc.nrcs.usda.gov/products/datasets/ssurg

o/index.html. General soils information presented in 

the State Soil Geographic Database (STATSGO) is 

presented in the Soils Technical Report (ALL 2001a). 

Information presented includes the areal extent, soil 

series characteristics, K-factor (erosion potential), 

salinity, and sodium adsorption ratio (SAR) for the 

various soil groups in the Powder River RMP and 

Billings RMP areas. The Soils Technical Report was 

prepared to present the potential impacts from the coal 

bed natural gas (CBNG) extraction process on land and 

the environment, with a focus on impacts to 

agriculture, and including potential effects on crops, 

livestock, and soils. The report was used to prepare this 

section and provides more detailed information 

pertaining to soils and CBNG development impacts to 

the environment. The complete Soils Technical Report 

can be accessed at http://www.mt.blm.gov/mcfo.

The layout of the soils in the study area is shown in 

Figures SOI-1 and SOI-2 for the Billings Resource 

Management Plan (RMP) Area and Powder River RMP 

area, respectively. A total of 163 soil mapping units 

composed of 205 soil series are present in the two 

RMP areas. The seven principal soil mapping units 

based on areal extent within the two RMP areas are:

• MT421 Cambeth-Megonot-Manning 

(4.3 percent)

• MT089 Yamac-Birney-Cabbart 

(4.3 percent)

• MT676 Yawdim-Delpoint-Thurlow 

(4.0 percent)

• MT675 Cabbart-Yawdim-Thurlow 

(3.9 percent)

• MT384 Marvan-Neldore-Bascovy 

(3.5 percent)

• MT103 Cabbart-Delpoint-Yamac 

(3.0 percent)

• MT559 Tanna-Rentsac-Yawdim 

(2.9 percent)

These seven soil mapping units compose 26 percent of 

the two RMP areas, with the remaining 156 soil 

mapping units making up the remainder. Table SOI-1 

presents all of the soil mapping units in the Billings 

RMP and Powder River RMP areas, along with the 

percent of the total RMP areas occupied by each 

mapping unit. Table SOI-2 presents some of the key 

soil characteristics related to erosion and salinity for 

the topmost 25 mapping units based on percent of total 

area.

Soils in the RMP areas are derived mainly from 

sedimentary bedrock and alluvium. The soils generally 

range from loams to clays, but are principally loams to 

silty clay loams.

Slope and K-factor are values that are used in the 

estimation of soil erosion potential. Slope values range 

up to greater than 40 percent; however, there are many 

soils that have slopes of zero to about 10 percent. 

Almost all of the soils have low K-factors (below 

0.37). Easily eroded soils have a K-factor between 0.37 

and 0.69, and resistant soils have a K-factor less than 

0.37 (Jarrett 1995). Figures presenting the mean 

K-factor of the soils in the Billings RMP and Powder 

River RMP areas are included in the Soils Technical 

Report (ALL 2001). Figures SOI-1 and SOI-2 are 

included here to summarize the information.

Soil salinity affects the suitability of a soil for crop 

production and the stability of the soil. The SAR is the 

measure of sodium relative to calcium and magnesium, 

and affects the soil structure and infiltration rate of 

water. The Soils Technical Report presents a more 

detailed discussion pertaining to the salinity and SAR 

of the soils in the Billings RMP and Powder River 

RMP areas. As shown in Table SOI-2, most of the soils 

are very low in salinity. The SAR values in the study 

areas and statewide vary widely and, with few 

exceptions, are low in sodium. Based on the generally 

fine texture of the surface soils (clayey), much of the 

soil will likely be susceptible to increasing sodicity 

when irrigated with water having a high SAR. 

Permeability is the measure of vertical water 

movement when the soil is saturated. The soil 

structure, porosity, gradation and texture all influence 

the permeability of the soil. Those soils with a coarser 

texture (sandy to loamy) and good internal drainage 

(higher permeability) will be the least susceptible to 

increasing sodicity and salinity. Much of the soil is 

likely to be irrigable with good management. 
SOILS APPENDIX

SOI-2

TABLE SOIL-1

AREAL EXTENT OF SOIL MAP UNITS FOR POWDER RIVER AND BILLINGS RMP AREAS

STATSGO

Map Unit Map Unit Name Acres

Percent of 

Area

MT001 Abac-Peritsa-Rock Outcrop 93,754 0.48

MT003 Absarokee-Castner-Sinnigam 436,268 2.25

MT004 Absarokee-Wayden-Redcreek Family 23,322 0.12

MT006 Absarokee-Castner-Grail 15,901 0.08

MT007 Absarokee-Hilger-Big Timber 70,560 0.36

MT016 Winler-Lismas-Swanboy 21,332 0.11

MT017 Archin-Twilight-Bonfri 78,323 0.4

MT019 Assinniboine-Pring-Archin 459,121 2.37

MT024 Badland-Bullock-Neldore 129,347 0.67

MT027 Bainville-Mcrae-Rock Outcrop 453,939 2.35

MT028 Bainville-Rock Outcrop-Travessilla 205,254 1.06

MT029 Bainville-Travessilla Family-Evanston 171,636 0.89

MT037 Beauvais-Hydro-Lambeth 83,773 0.43

MT041 Bew-Toluca-Nobe 8,032 0.04

MT042 Big Timber-Cabba-Absarokee 107,565 0.56

MT048 Bitton-Shambo-Doney 428,667 2.22

MT051 Blackhall-Twilight-Zeona 21,144 0.11

MT054 Cabbart-Bonfri-Cambeth 2 <0.01

MT055 Bonfri-Gerdrum-Galbreth 3,927 0.02

MT070 Bryant-Doney-Shambo 56,522 0.29

MT075 Yamac-Busby-Cabbart 104,872 0.54

MT076 Cabba-Travessilla Family-Birney 121,597 0.63

MT078 Cabba-Campspass-Farland 6,969 0.04

MT080 Cabba-Farland-Yawdim 38,170 0.2

MT083 Cabba-Ringling-Yawdim 300,378 1.55

MT084 Cabba-Ringling-Yawdim 493,159 2.55

MT089 Yamac-Birney-Cabbart 827,152 4.27

MT090 Cabbart-Cambeth-Bonfri 183,942 0.95

MT092 Delpoint-Cabbart-Yamac 552,861 2.86
SOILS APPENDIX

SOI-3

TABLE SOIL-1

AREAL EXTENT OF SOIL MAP UNITS FOR POWDER RIVER AND BILLINGS RMP AREAS

STATSGO

Map Unit Map Unit Name Acres

Percent of 

Area

MT095 Cabbart-Keiser-Dast 57,076 0.29

MT096 Cabbart-Pultney Family-Stormitt 43,281 0.22

MT097 Cabbart-Rentsac-Delpoint 283,471 1.46

MT099 Cabbart-Rock Outcrop-Twilight 116,567 0.6

MT100 Cabbart-Twilight-Forelle 31,738 0.16

MT103 Cabbart-Delpoint-Yamac 577,016 2.98

MT112 Castner-Savage-Chama 5,667 0.03

MT113 Castner-Chama-Regent 4,089 0.02

MT114 Castner-Darret-Windham 3 <0.01

MT120 Wayden-Castner-Cabba 47,803 0.25

MT127 Chinook-Archin-Delpoint 6 <0.01

MT145 Crago-Musselshell-Attewan 545,006 2.82

MT146 Crago-Musselshell-Fairfield 7,046 0.04

MT148 Creed-Gerdrum-Forelle 1,072 0.01

MT152 Cushman-Yawdim-Bainville 54,706 0.28

MT153 Danvers-Tinsley-Oburn 72,675 0.38

MT155 Danvers-Judith-Windham 49,063 0.25

MT157 Dast-Forelle-Delpoint 31,137 0.16

MT159 Dast-Mcrae-Travessilla Family 84,373 0.44

MT161 Degrand-Kremlin-Ethridge 10,319 0.05

MT164 Cabbart-Delpoint-Yamac 278,907 1.44

MT165 Delpoint Family-Kirby-Delpoint 33,440 0.17

MT167 Delpoint-Travessilla Family-Cabbart 216,026 1.12

MT168 Delpoint-Cabbart-Yamac 105,771 0.55

MT173 Dolus-Boxwell-Castner 22,680 0.12

MT174 Doney-Reeder-Cabba 72,377 0.37

MT175 Doney-Shaak-Wayden 232,912 1.2

MT176 Doney-Winifred-Wayden 73,711 0.38

MT182 Starley-Rock Outcrop-Babb 147,700 0.76
SOILS APPENDIX

SOI-4

TABLE SOIL-1

AREAL EXTENT OF SOIL MAP UNITS FOR POWDER RIVER AND BILLINGS RMP AREAS

STATSGO

Map Unit Map Unit Name Acres

Percent of 

Area

MT187 Ethridge-Kremlin-Marias 9,089 0.05

MT190 Evanston-Lonna-Tinsley 19,800 0.1

MT193 Fairway Family-Tetonview-Villy 8,546 0.04

MT209 Forkwood-Vonalee-Haverdad 31,675 0.16

MT213 Garlet-Cowood-Rock Outcrop 298 <0.01

MT216 Garlet-Rubble Land-Cowood 2,132 0.01

MT217 Garlet-Sebud-Cheadle 22,544 0.12

MT218 Shadow-Garlet-Macfarlane 257,150 1.33

MT224 Gerdrum-Forelle-Archin 38,201 0.2

MT225 Harlem-Gerdrum-Ethridge 26,205 0.14

MT228 Gilt Edge-Absher-Yawdim 11,675 0.06

MT247 Harlem-Vanda-Marvan 10,450 0.05

MT249 Stormitt-Harvey Family-Nihill 48,815 0.25

MT252 Haverson-Heldt-Toluca 16,832 0.09

MT254 Havre-Glendive-Water 30,577 0.16

MT255 Havre-Harlem-Attewan 25,454 0.13

MT256 Havre-Harlem-Glendive 88,473 0.46

MT258 Havre-Ryell-Harlem 50,431 0.26

MT259 Havre-Hanly-Glendive 173,933 0.9

MT261 Havre-Rivra-Water 114,549 0.59

MT263 Havre-Kobar-Spinekop 47,424 0.25

MT264 Havre-Glendive-Yamac 10,938 0.06

MT269 Heath-Charlos-Maurice 58,449 0.3

MT271 Heldt-Fort Collins-Kobar 43,967 0.23

MT273 Helmville-Whitore-Tropal 126,307 0.65

MT301 Keiser-Hydro-Gilt Edge 112,102 0.58

MT309 Kobar-Yamac-Attewan 23,490 0.12

MT321 Lamedeer-Ringling-Twin Creek 35,383 0.18

MT323 Lap-Windham-Armington 104,714 0.54
SOILS APPENDIX

SOI-5

TABLE SOIL-1

AREAL EXTENT OF SOIL MAP UNITS FOR POWDER RIVER AND BILLINGS RMP AREAS

STATSGO

Map Unit Map Unit Name Acres

Percent of 

Area

MT324 Lardell-Mckenzie-Kobar 28,542 0.15

MT327 Libeg-Leavitt-Hanson 17,866 0.09

MT336 Lihen-Delpoint-Tinsley 5,762 0.03

MT338 Lisam-Abor-Vanda 303,030 1.57

MT339 Lisam-Abor-Hesper 28,331 0.15

MT349 Lolo-Work-Shawa 39,683 0.21

MT365 Maginnis-Absarokee-Rock Outcrop 116,071 0.6

MT369 Marias-Havre-Harlem 143,781 0.74

MT374 Martinsdale-Fairfield-Reeder 7 <0.01

MT379 Marvan-Abor-Neldore 97,192 0.5

MT382 Marvan-Gerdrum-Vanda 200,503 1.04

MT383 Harlem-Vanda-Marvan 23,594 0.12

MT384 Marvan-Neldore-Bascovy 677,263 3.5

MT393 Mcrae-Harlem-Keiser 103,536 0.54

MT396 Midway-Shingle-Rock Outcrop 76,447 0.4

MT400 Mirror-Bross-Vasquez 56,548 0.29

MT407 Moyerson-Rock Outcrop-Orinoco 253,541 1.31

MT414 Neldore-Abor-Vanda 7,787 0.04

MT415 Neldore-Abor-Volborg 93,856 0.49

MT421 Cambeth-Megonot-Manning 829,387 4.29

MT433 Nunn-Toluca-Heldt 5,480 0.03

MT438 Bridger-Bynum-Owen Creek 16,109 0.08

MT456 Pinelli-Glendive-Busby 4,780 0.02

MT459 Prospect-Sublette-Teton 9,292 0.05

MT466 Reeder Family-Barvon-Mowbray 136,554 0.71

MT471 Rentsac-Cabbart-Blackhall 24,662 0.13

MT472 Yawdim-Rentsac-Lambeth 149,344 0.77

MT474 Broadus-Ridge-Cabba 42,375 0.22

MT475 Ringling-Cabba-Relan 16,537 0.09
SOILS APPENDIX

SOI-6

TABLE SOIL-1

AREAL EXTENT OF SOIL MAP UNITS FOR POWDER RIVER AND BILLINGS RMP AREAS

STATSGO

Map Unit Map Unit Name Acres

Percent of 

Area

MT484 Rock Outcrop-Dryadine-Rubble Land 3,611 0.02

MT485 Garlet-Rock Outcrop-Cryoborolls 21,066 0.11

MT486 Rock Outcrop-Hanson-Whitecow 159,584 0.82

MT488 Rock Outcrop-Midway-Travessilla Family 236,799 1.22

MT489 Abor-Rock Outcrop-Delpoint 17,571 0.09

MT492 Rock Outcrop-Rubble Land-Cowood 127,770 0.66

MT497 Rock Outcrop-Water-Rubble Land 68,075 0.35

MT499 Romberg-Calicott-Hiland 28,655 0.15

MT500 Romberg-Naturita-Heldt 40,683 0.21

MT519 Savage-Forelle-Frazer 68,982 0.36

MT522 Savage-Work-Chama 4,497 0.02

MT532 Shadow-Garlet-Water 48,413 0.25

MT538 Skaggs-Starley-Raynesford 25 <0.01

MT547 Garlet-Stemple-Tigeron 1,244 0.01

MT550 Sweetgrass-Hilger-Fairfield 227,202 1.17

MT555 Tamaneen-Judith-Windham 53,564 0.28

MT559 Tanna-Rentsac-Yawdim 567,531 2.93

MT569 Yawdim-Thurlow-Cabbart 116,568 0.6

MT572 Tigeron-Garlet-Worock 142,349 0.74

MT575 Tinsley-Keiser-Yawdim 141,874 0.73

MT588 Work-Turner-Wayden 149,865 0.77

MT590 Twilight-Blackhall-Busby 22,004 0.11

MT594 Vananda-Gerdrum-Mckenzie 60,705 0.31

MT597 Vanstel-Cabbart-Delpoint 72,598 0.38

MT612 Wanetta-Hesper-Bitton 30,042 0.16

MT617 Wayden-Abac-Rock Outcrop 91,333 0.47

MT618 Wayden-Regent-Doney 82,113 0.42

MT619 Wayden-Eltsac-Maschetah 186,591 0.96

MT623 Whitecow-Mocmont-Hughesville 41,880 0.22
SOILS APPENDIX

SOI-7

TABLE SOIL-1

AREAL EXTENT OF SOIL MAP UNITS FOR POWDER RIVER AND BILLINGS RMP AREAS

STATSGO

Map Unit Map Unit Name Acres

Percent of 

Area

MT659 Wormser-Lavina-Yawdim 29,616 0.15

MT661 Worock-Garlet-Rock Outcrop 3,050 0.02

MT668 Yamac-Havre-Birney 211,006 1.09

MT669 Yamac-Kobar-Marvan 22,214 0.11

MT673 Yawdim-Abor-Vananda 179,618 0.93

MT674 Cabbart-Yawdim-Delpoint 147,969 0.76

MT675 Cabbart-Yawdim-Thurlow 758,425 3.92

MT676 Yawdim-Delpoint-Thurlow 770,758 3.98

MT677 Yawdim-Delpoint-Gerdrum 82,348 0.43

MT678 Yawdim-Ethridge-Rock Outcrop 70,647 0.37

MT679 Cabbart-Yawdim-Hesper 189,351 0.98

MT680 Yawdim-Orinoco-Amherst 214,696 1.11

MT690 Welring-Clifterson-Shavano 2,718 0.01

MT691 Ulm-Maggin-Louviers 7,403 0.04

MT692 Shingle-Renohill-Ulm 36,589 0.19

MT693 Samday-Shingle-Parmleed 7,705 0.04

MT694 Orella-Epsie-Winler 26,102 0.13

MT695 Haverdad-Havre-Zigweid 14,472 0.07

Source: USDA NRSC State Soil Geographic Database 1996
SOI-8
SOI-9
SOILS APPENDIX

SOI-10

TABLE SOIL-2

SOIL SERIES CHARACTERISTICS FOR POWDER RIVER & BILLINGS RMP AREAS

STATSGO 

Map Unit

Major Soil 

Series Surface Texture K-factor1

Depth 

(in)

Slope 

(%)

Salinity2 

(mmhos/cm)

Permeability 

(in/hr)

MT421 Cambeth silt loam 0.37 6 4-25 0.6-0.2

(4.3 %) Megonot silty clay loam 0.37 5 4-15 0.06-0.2

Manning loam 0.32 5 8-15 2-6

MT089 Cabbart loam 0.37 3 15-70 0-4 0.6-0.2

(4.3 %) Birney channery loam 0.2 5 25-70 0-2 0.6-0.2

Yamac loam 0.37 5 15-25 0.6-0.2

MT676 Yawdim silty clay loam 0.37 3 8-35 0.2-0.6

(4.0 %) Delpoint loam 0.37 3 8-35 0-4 0.6-2

Thurlow silty clay loam 0.32 4 0-8 0.6-2

MT675 Yawdim clay loam 0.37 3 8-70 0.2-0.6

(3.9 %) Cabbart silt loam 0.37 3 15-75 0-4 0.2-0.6

Thurlow silty clay loam 0.32 4 2-15 0.2-0.6

MT384 Marvan silty clay 0.37 4 0-8 0-4 0.06-0.2

(3.5 %) Neldore clay 0.32 3 4-15 0-2 0.06-0.2

Bascovy clay 0.37 6 2-15 2-4 0.06-0.2

MT103 Cabbart loam 0.37 3 6-45 0-4 0.6-2

(3.0 %) Delpoint loam 0.37 3 15-35 0-4 0.6-2

Yamac loam 0.37 5 2-8 0.6-2

MT559 Tanna clay loam 0.37 6 2-8 0.06-0.2

(2.9 %) Rentsac channery loam 0.2 7 4-15 0.6-2

Yawdim clay loam 0.37 3 25-60 0.2-0.6

MT092 Cabbart loam 0.37 3 8-70 0-4 0.6-2

(2.9 %) Delpoint loam 0.37 3 15-25 0-4 0.6-2

Yamac loam 0.37 5 2-8 0.6-2

MT145 Crago loam 0.37 4 0-4 0.6-2

(2.8%) Musselshell loam 0.37 3 0-2 0.6-2

Attewan loam 0.37 6 0-2 0.6-2
SOILS APPENDIX

SOI-11

TABLE SOIL-2

SOIL SERIES CHARACTERISTICS FOR POWDER RIVER & BILLINGS RMP AREAS

STATSGO 

Map Unit

Major Soil 

Series Surface Texture K-factor1

Depth 

(in)

Slope 

(%)

Salinity2 

(mmhos/cm)

Permeability 

(in/hr)

MT084 Cabba silt loam 0.37 3 15-50 0-4 0.6-2

(2.6 %) Ringling channery-loam 0.17 5 5-50 0.6-2

Yawdim clay loam 0.37 3 8-70 0.2-0.6

MT019 Assinniboine sandy clay loam 0.32 6 2-8 0.6-2

(2.4 %) Pring sandy loam 0.2 10 2-8 2-6

Archin loam 0.43 12 2-8 0-2 0.6-2

MT027 Bainville loam 0.37 4 2-15 0.6-2

(2.4 %) Rock Outcrop unweathered 

bedrock

0 60 25-60 0.6-2

Mcrae loam 0.37 5 7-15 0-2 0.6-2

MT003 Absarokee clay loam 0.32 8 2-50 0-2 0.6-2

(2.3 %) Castner channery loam 0.2 6 15-50 0.6-2

Sinnigam clay loam 0.37 6 2-15 0.06-0.2

MT048 Bitton channery loam 0.24 11 25-70 0-2 2-6

(2.2 %) Shambo loam 0.37 5 0-8 0.6-2

Doney loam 0.37 4 2-70 0-2 0.6-2

MT338 Lisam clay 0.37 3 4-35 0-2 0.06-0.2

(1.6 %) Abor clay 0.37 6 4-15 0-4 0.2-0.6

Vanda clay 0.37 4 0-8 2-8 0.01-0.06

MT083 Cabba silt loam 0.37 3 15-50 0-4 0.6-2

(1.6 %) Ringling channery loam 0.17 5 6-50 0.6-2

Yawdim clay loam 0.37 3 8-70 0.2-0.6

MT097 Cabbart loam 0.37 3 8-35 0-4 0.6-2

(1.5 %) Rentsac channery loam 0.2 7 8-35 2-6

Delpoint loam 0.37 3 8-15 0-4 0.6-2

MT164 Delpoint loam 0.37 3 2-15 0-4 0.6-2

(1.4 %) Cabbart loam 0.37 3 2-35 0-4 0.6-2

Yamac loam 0.37 5 2-15 0.6-2

MT218 Shadow

very channery 

loam 0.1 3 25-60

2-6

(1.3 %) Macfarlane

extremely stony

loam 0.05 18 25-50

2-6

Garlet stony loam 0.2 4 25-60 0.6-2

MT407 Moyerson silty clay loam 0.32 4 4-50 0-4 0.06-0.2

(1.3 %) Orinoco silty clay loam 0.32 7 2-15 0.2-0.6

Rock Outcrop

unweathered 

bedrock 0 60 0-99 0.2-0.6
SOILS APPENDIX

SOI-12

TABLE SOIL-2

SOIL SERIES CHARACTERISTICS FOR POWDER RIVER & BILLINGS RMP AREAS

STATSGO 

Map Unit

Major Soil 

Series Surface Texture K-factor1

Depth 

(in)

Slope 

(%)

Salinity2 

(mmhos/cm)

Permeability 

(in/hr)

MT488 Midway silty clay loam 0.43 3 15-45 2-4 0.2-0.6

(1.2 %) Travessilla 

Family

silt loam 0.32 2 15-70 0.6-2

Rock Outcrop unweathered 

bedrock

0 60 0-99 0.6-2

MT175 Doney loam 0.37 4 8-70 0-2 0.6-2

(1.2 %) Wayden silty clay loam 0.37 6 8-35 0-4 0.6-2

Shaak clay loam 0.37 6 1-15 0.06-0.2

MT550 Sweetgrass gravelly loam 0.17 4 0-4 0.6-2

(1.2 %) Hilger very stony loam 0.2 5 2-4 0.6-2

Fairfield clay loam 0.17 7 2-4 0.6-2

MT167 Travessilla 

Family

fine sandy loam 0.2 2 8-35 2-6

(1.1 %) Delpoint loam 0.37 3 8-15 0-4 0.6-2

Cabbart loam 0.37 3 8-35 0-4 0.6-2

MT680 Yawdim silty clay 0.32 3 4-15 0.06-0.2

(1.1 %) Orinoco silty clay 0.28 7 4-15 0.2-0.6

Amherst clay loam 0.32 5 1-15 0.6-2

MT668 Yamac loam 0.37 5 0-8 0.6-2

(1.1 %) Havre silty clay loam 0.32 8 0-2 0-2 0.2-0.6

Birney channery-loam 0.2 5 15-35 0-2 0.6-2

Source: USDA NRCS State Soil Geographic Database 1996

Note: Only the top 25 Map Units based on total acreage are included (percent in parenthesis). 58 percent of the soils in the study area are represented.

1 Soil erosion factor indicates the susceptibility of a soil to sheet and rill erosion. Possible range of values is from 0.02 to 0.69, with higher values 

being more susceptible to erosion.

2 Measure of the amount of soluble salts in a soil at saturation, also expressed as electrical conductivity (EC).