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Montana Field Guide

Montana Field Guides

Shale Badland

Provisional State Rank: S4
(see reason below)

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State Rank Reason
There are numerous large patches of this system well-distributed across southwestern Montana, and although oil/gas exploration poses a threat, it has not yet been extensively realized. Grazing has the potential to cause significant damage to these systems, but the steep terrain and sparse vegetation generally deters livestock, except in areas where surrounding grasslands and steppe is in poor condition.

General Description

This system is represented in the Wyoming basin ecoregion of south-central Montana, and in the Missouri river region of east-central Montana. It is composed of barren and sparsely vegetated substrates with less than 10% plant cover. This system is primarily found on eroded, rounded hills and plains that form a rolling topography. A combination of factors such as elevation, rainfall, the carving action of water and wind, and parent material contribute to the development of this system. It is primarily a type of mature dissection with finely textured drainage pattern and moderately steep slopes. This system contains extremely dry and easily erodible, consolidated silty to clayey soils with bands of shale, siltstones, mudstones or isolated consolidates. Harsh soil properties and high rates of erosion and deposition are driving environmental variables supporting sparse dwarf-shrubs such as saltbush (Atriplex species), sagebrush (Artemisia species), green rabbitbrush (Chrysothamnus viscidiflorus), rubber rabbitbrush (Ericameria nauseosa), greasewood (Sarcobatus vermiculatus), and sparse herbaceous vegetation. Indian ricegrass (Achnatherum hymenoides) is characteristic of early-seral vegetation through much of this system's range. Grazing and oil and gas exploration constitute the major threats to this system.

Diagnostic Characteristics
Badland, shale and mudstone, alkaline silt or clay soils, less than 10% vegetation cover.

Similar Systems

The system is common throughout the Wyoming Basin ecoregion in south-central Montana, especially on the southern and western flanks of the Pryor Mountains. It also occurs in the Missouri River breaks area around Fort Peck.

Ecological System Distribution
Approximately 343 square kilometers are classified as Shale Badland in the 2017 Montana Land Cover layers.  Grid on map is based on USGS 7.5 minute quadrangle map boundaries.

Montana Counties of Occurrence
Blaine, Carbon, Fergus, Garfield, Mccone, Petroleum, Phillips, Valley

Spatial Pattern
Large patch

This system is primarily found on eroded rounded hills and plains that form a rolling topography with moderately steep slopes. It is found within an arid to semi-arid climate where infrequent but torrential rains cause erosion. Shale badlands often occur on exposed ridges and steep colluvial slopes. They may take the form of fans or aprons at the base of steep areas or as barren badland hills with rolling topography (Colorado Natural Heritage Program 2005). Soils are extremely dry and easily erodible, usually consolidated silty to clayey soils with bands of shale, siltstones, mudstones, or isolated consolidates. Most commonly, the soils are alkaline silts or bentonite clays (water-weathered volcanic ash), typically derived from marine shales. Harsh soil properties and high rates of erosion and deposition are driving environmental variables supporting sparse vegetation cover.


This system is typically sparsely vegetated (less than 10 percent cover) with a mixture of shrub and herbaceous species. In southwestern Montana, common shrubs include big sagebrush (Artemisia tridentata ssp. tridentata), fourwing saltbush (Atriplex canescens), green rabbitbrush (Chrysothamnus viscidiflorus), rubber rabbitbrush (Ericameria nauseosa), greasewood (Sarcobatus vermiculatus), Gardner’s saltbush (Atriplex gardneri), and horsebrush (Tetradymia species). Shrubs are commonly dominant on mid-to late-seral stands, and rubber rabbitbrush (Ericameria nauseosa) can be found at any stage. These shrub species are primarily found in drainage ways where water collects (Godfrey 1997). In Montana, graminoid cover is very sparse. Indian ricegrass (Achnatherum hymenoides) is characteristic of early-seral vegetation through much of this system's range. Other species include needle and thread (Hesperostipa comata), alkali sacaton (Sporobolus airoides), saline wildrye (Leymus salinus), bluebunch wheatgrass (Pseudoroegneria spicata), western wheatgrass (Pascopyrum smithii) and dry, upland muhly species (Muhlenbergia spp.). Common forbs include buckwheat (Eriogonum species), western sagewort (Artemisia ludoviciana), knotweed (Polygonum species), threadleaf snakeweed(Gutierrezia sarothrae), bladder twinpod (Physaria species), sandwort (Arenaria species), stemless four nerve daisy (Tetraneuris acaulis), rock evening primrose (Oenothera cespitosa), and penstemon (Penstemon species).

National Vegetation Classification Switch to Full NVC View

Adapted from US National Vegetation Classification

A1110 Atriplex gardneri Low Scrub Alliance
CEGL001438 Atriplex gardneri Dwarf-shrubland
CEGL001444 Atriplex gardneri - Achnatherum hymenoides Dwarf-shrubland
A1262 Achnatherum hymenoides - Pseudoroegneria spicata - Muhlenbergia pungens Grassland Alliance
A3221 Artemisia arbuscula ssp. Longiloba Steppe & Shrubland Alliance
CEGL002585 Artemisia arbuscula ssp. longiloba - Elymus lanceolatus Shrubland
A4052 Ephedra spp. - Leymus salinus - Eriogonum corymbosum Badlands Cold Desert Sparse Vegetation Alliance
CEGL001667 Pseudoroegneria spicata / Eriogonum brevicaule Sparse Vegetation
*Disclaimer: Alliances and Associations have not yet been finalized in the National Vegetation Classification (NVC) standard.  A complete version of the NVC for Montana can be found here.

Dynamic Processes
Communities associated with this ecological system are adapted to highly erodible soils that may be dry throughout the growing season. They may also occur on shallow soils, with parent material and/or shale bedrock formation close to the surface. Surface soils are subject to yearly gravitational down-slope movement, especially after a rainstorm, where plants may get buried or uprooted due to silt movement (Colorado Natural Heritage Program 2005). Generally, the plant communities will be drought tolerant, grazing resistant, and winter hardy, and will be tolerant of managed grazing practices or light-intensity fires. Because of the erodible soils, the shale badlands system is not tolerant of heavy use.

Grazing and oil and gas exploration constitute the major threats to this system. This system does not support intensive grazing practices due to sparse vegetation and highly erodible soils.

Restoration Considerations
Eliminating grazing may allow the sparse vegetation to recover. In areas of disturbance and heavy erosion, supplemental planting of shrubs may be required and should be limited to microsites where available soil moisture persists longer into the growing season.

Species Associated with this Ecological System
  • Details on Creation and Suggested Uses and Limitations
    How Associations Were Made
    We associated the use and habitat quality (common or occasional) of each of the 82 ecological systems mapped in Montana for vertebrate animal species that regularly breed, overwinter, or migrate through the state by:
    1. Using personal observations and reviewing literature that summarize the breeding, overwintering, or migratory habitat requirements of each species (Dobkin 1992, Hart et al. 1998, Hutto and Young 1999, Maxell 2000, Foresman 2012, Adams 2003, and Werner et al. 2004);
    2. Evaluating structural characteristics and distribution of each ecological system relative to the species' range and habitat requirements;
    3. Examining the observation records for each species in the state-wide point observation database associated with each ecological system;
    4. Calculating the percentage of observations associated with each ecological system relative to the percent of Montana covered by each ecological system to get a measure of "observations versus availability of habitat".
    Species that breed in Montana were only evaluated for breeding habitat use, species that only overwinter in Montana were only evaluated for overwintering habitat use, and species that only migrate through Montana were only evaluated for migratory habitat use.  In general, species were listed as associated with an ecological system if structural characteristics of used habitat documented in the literature were present in the ecological system or large numbers of point observations were associated with the ecological system.  However, species were not listed as associated with an ecological system if there was no support in the literature for use of structural characteristics in an ecological system, even if point observations were associated with that system.  Common versus occasional association with an ecological system was assigned based on the degree to which the structural characteristics of an ecological system matched the preferred structural habitat characteristics for each species as represented in scientific literature.  The percentage of observations associated with each ecological system relative to the percent of Montana covered by each ecological system was also used to guide assignment of common versus occasional association.  If you have any questions or comments on species associations with ecological systems, please contact the Montana Natural Heritage Program's Senior Zoologist.

    Suggested Uses and Limitations
    Species associations with ecological systems should be used to generate potential lists of species that may occupy broader landscapes for the purposes of landscape-level planning.  These potential lists of species should not be used in place of documented occurrences of species (this information can be requested at: or systematic surveys for species and evaluations of habitat at a local site level by trained biologists.  Users of this information should be aware that the land cover data used to generate species associations is based on imagery from the late 1990s and early 2000s and was only intended to be used at broader landscape scales.  Land cover mapping accuracy is particularly problematic when the systems occur as small patches or where the land cover types have been altered over the past decade.  Thus, particular caution should be used when using the associations in assessments of smaller areas (e.g., evaluations of public land survey sections).  Finally, although a species may be associated with a particular ecological system within its known geographic range, portions of that ecological system may occur outside of the species' known geographic range.

    Literature Cited
    • Adams, R.A.  2003.  Bats of the Rocky Mountain West; natural history, ecology, and conservation.  Boulder, CO: University Press of Colorado.  289 p.
    • Dobkin, D. S.  1992.  Neotropical migrant land birds in the Northern Rockies and Great Plains. USDA Forest Service, Northern Region. Publication No. R1-93-34.  Missoula, MT.
    • Foresman, K.R.  2012.  Mammals of Montana.  Second edition.  Mountain Press Publishing, Missoula, Montana.  429 pp.
    • Hart, M.M., W.A. Williams, P.C. Thornton, K.P. McLaughlin, C.M. Tobalske, B.A. Maxell, D.P. Hendricks, C.R. Peterson, and R.L. Redmond. 1998.  Montana atlas of terrestrial vertebrates.  Montana Cooperative Wildlife Research Unit, University of Montana, Missoula, MT.  1302 p.
    • Hutto, R.L. and J.S. Young.  1999.  Habitat relationships of landbirds in the Northern Region, USDA Forest Service, Rocky Mountain Research Station RMRS-GTR-32.  72 p.
    • Maxell, B.A.  2000.  Management of Montana's amphibians: a review of factors that may present a risk to population viability and accounts on the identification, distribution, taxonomy, habitat use, natural history, and the status and conservation of individual species.  Report to U.S. Forest Service Region 1.  Missoula, MT: Wildlife Biology Program, University of Montana.  161 p.
    • Werner, J.K., B.A. Maxell, P. Hendricks, and D. Flath.  2004.  Amphibians and reptiles of Montana.  Missoula, MT: Mountain Press Publishing Company. 262 p.

Original Concept Authors
Natureserve Western Ecology Group

Montana Version Authors
E. Luther, L.K. Vance, T. Luna

Version Date

  • Classification and Map Identifiers

    Cowardin Wetland Classification: Not applicable

    NatureServe Identifiers:
    Element Global ID 28626
    System Code CES304.789, Inter-Mountain Basins Shale Badland

    National Land Cover Dataset:
    31: Barren Land

    3139: Inter-Mountain Basins Shale Badland

  • Additional ReferencesLegend:   View Online Publication
    Do you know of a citation we're missing?
    • Colorado Natural Heritage Program. 2005. Ecological System Descriptions and Viability Guidelines for Colorado. Colorado Natural Heritage Program, Colorado State University, Fort Collins, Colorado.
    • Godfrey, A.E. 1997. Mass Movement of Mancos Shale Crust near Caineville, Utah: A 30-Year Record. Geografiska Annaler 79(3): 185-194

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Citation for data on this website:
Shale Badland — Inter-Mountain Basins Shale Badland.  Montana Field Guide.  Retrieved on , from