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Montana Field Guide

Montana Field Guides

Great Plains Cliff and Outcrop

Provisional State Rank: S5

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General Description

This system includes cliffs and outcrops throughout the Western Great Plains. Substrate can range from sandstone and limestone, which can often form bands in the examples of this system. This system includes cliffs and outcrops throughout the Western Great Plains. Substrate can range from sandstone and limestone, which can often form bands in the examples of this system. Vegetation is restricted to shelves, cracks and crevices in the rock. This system differs from Great Plains Badlands in that often the soil is slightly developed and less erodible, and some grass and shrub species can occur with a cover of more than 10 percent. Common species in this system include short shrubs such as three leaf sumac (Rhus trilobata) and sagebrush (Artemisia spp.), and mixed grass species such as sideoats grama (Bouteloua curtipendula), blue grama (Bouteloua gracilis) and prairie sandreed (Calamovilfa longifolia). This system is embedded within the mixed grass and sand prairie regions of eastern Montana and the fescue grasslands of the northwestern Great Plains region. Climate is typical of mid continental regions with long severe winters and warm summers. Precipitation ranges from 300 to 650 millimeters (12 to 26 inches) with two-thirds coming during the summer and most of the other third in the spring. The growing season is on average 115 days, although the growing season ranges from 100 days on the Canadian border to 130 days on the Wyoming border. Typical land use is grazing.

Diagnostic Characteristics
Less than 10% vegetation cover, cliff, ustic soils, very shallow soils, flood scouring

Similar Systems

This system is scattered throughout eastern Montana and the northwestern glaciated plains where eroded landscapes impair the ability of vegetation to thrive. Elsewhere, this system is found at scattered locations from southern Manitoba and North Dakota, south to northwestern Texas and the eastern half of the Rocky Mountain states south to New Mexico.

Ecological System Distribution
Approximately 106 square kilometers are classified as Great Plains Cliff and Outcrop in the 2017 Montana Land Cover layers.  Grid on map is based on USGS 7.5 minute quadrangle map boundaries.

Montana Counties of Occurrence
Big Horn, Blaine, Carbon, Carter, Cascade, Chouteau, Custer, Dawson, Fallon, Fergus, Garfield, Glacier, Golden Valley, Hill, Judith Basin, Lewis and Clark, Liberty, Mccone, Meagher, Musselshell, Park, Petroleum, Phillips, Pondera, Powder River, Prairie, Richland, Roosevelt, Rosebud, Stillwater, Sweet Grass, Teton, Toole, Treasure, Valley, Wheatland, Wibaux, Yellowstone

Spatial Pattern
Small patch

These systems are primarily found on cliffs and outcrops throughout the western Great Plains region of Montana. Landforms such as buttes, mesas, and eroded cliff bands constitute the major landforms. It is found within an arid to semi-arid climate with infrequent, but torrential, rains that cause erosion. A combination of other factors such as elevation, wind erosion, and parent material can also contribute to its development. This system contains pockets of soil development below the cliff faces, usually derived from limestone and sandstone parent materials. Vegetation in these shallow soil communities are subject to conditions different from those of the surrounding ecosystems (Crow & Ware 2007). Soils are dry and easily erodible, and due to their shallow nature soil surface temperatures can vary widely. Thus, cliffs provide a unique environment for plants adapted to these conditions (Graham & Knight 2004).


Vegetation is restricted to shelves, cracks and crevices in the rock and is typically sparse. Endemic and other characteristic outcrop species have adapted well to the shallow soil habitat of outcrops (Crow & Ware 2007). Vegetation is typically a mixture of shrub and herbaceous species. Common shrubs include three leaf sumac, greasewood (Sarcobatus vermiculatus), Gardner’s saltbush (Atriplex gardneri), big sagebrush (Artemisia tridentata), silver sagebrush (Artemisia cana), rabbitbrush (Chrysothamnus species) and saltbush (Atriplex species). In the northwestern Great Plains region of Montana, it can include horizontal juniper (Juniperus horizontalis), common juniper (Juniperus communis), bearberry (Arctostaphylos uva-ursi), and shrubby cinquefoil (Dasiphora fruticosa).

Forbs adapted to sandy soils and sandstone and limestone substrates inhabit this system. Common species include buckwheat (Eriogonum species), threadleaf snakeweed (Gutierrezia sarothrae), Hooker’s sandwort (Arenaria hookeri), bud sagebrush (Picrothamnus desertorum), curlycup gumweed (Grindelia squarrosa), bladderpod (Lesquerella species), twinpod (Physariaspecies), douglasia (Douglasia montana), rock evening primrose (Oenothera cespitosa), four-nerve daisy (Tetraneuris acaulis) and penstemon (Penstemon species). In Montana, graminoid cover is typically sparse. Species include sideoats grama, blue grama, prairie sandreed, western wheatgrass (Pascopyrum smithii), bluebunch wheatgrass (Pseudoroegneria spicata), and Indian ricegrass (Achnatherum hymenoides).

National Vegetation Classification Switch to Full NVC View

Adapted from US National Vegetation Classification

A1874 Artemisia longifolia Badlands Alliance
CEGL001521 Artemisia longifolia / Calamovilfa longifolia Sparse Vegetation
A3981 Great Plains Acidic Cliff Alliance
CEGL002290 Sandstone Great Plains Xeric Butte - Bluff 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 soils that may be dry throughout the growing season. Typically, soils are more developed than in similar badlands systems and are derived from sandstone or limestone. Drought and wind erosion are the most common natural dynamics affecting this system (Colorado Natural Heritage Program 2005). Communities can be tolerant of managed grazing practices or light-intensity fires, but are not tolerant of heavy use on the landscape due to easily erodible conditions. Soils can also be strongly influenced by infrequent, but often torrential, rains. Invasive species can become established where there is frequent disturbance.

This system is usually not subjected to heavy grazing or human disturbances. However, invasive species can out-compete existing herbaceous native vegetation within this system.

Restoration Considerations
Eliminating grazing or implementing light grazing regimes may allow the sparse vegetation to recover.

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, S.V. Cooper, T. Luna, and L.K.Vance

Version Date

  • Classification and Map Identifiers

    Cowardin Wetland Classification: Not applicable

    NatureServe Identifiers:
    Element Global ID 28522
    System Code CES303.665, Western Great Plains Cliff and Outcrop

    National Land Cover Dataset:
    31: Barren Land

    3142: Western Great Plains Cliff and Outcrop

  • 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.
    • Crow, S.E. and S. Ware. 2007. Soil Type Tolerance in Rocky Outcrop Plants: Species of Non-Calcareous Substrates. The Southwest Naturalist 52(1): 120-125
    • Graham, L. and R.L. Knight. 2004. Multi-Scale Comparisons of Cliff Vegetation in Colorado. Plant Ecology 170(2): 223-234

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Citation for data on this website:
Great Plains Cliff and Outcrop — Western Great Plains Cliff and Outcrop.  Montana Field Guide.  Retrieved on , from