Great Plains Cliff and Rock Outcrops
Global Name:
Great Plains Cliff, Scree & Rock Vegetation
Global Rank:
G4G5
State Rank:
S5
(see reason below)
External Links
State Rank Reason
These rocky and sparsely-vegetated habitats are widespread. They are not threatened nor intrinsically vulnerable.
General Description
This National Vegetation Classification Group is composed of cliffs, bluffs, and rock outcrops throughout the Great Plains Region in MT. Substrates are sedimentary, typically sandstones and limestones. It is characteristically dry and sparsely vegetated, typically having less than 10% plant cover. There may be small patches of dense vegetation, or scattered plants within these communities. Vegetation is restricted to shelves, cracks and crevices in the rock. This group differs from the Great Plains Badlands in that soil development is much more limited, exposed rock is generally much greater, and the Badlands group can have vegetation cover greater than 10 percent. This group is embedded within the mixed grass and sand prairie regions of eastern Montana and the fescue grasslands of the northwestern Great Plains region. The climate is typical of mid continental regions with long, severe winters and warm summers.
This group is equivalent to the Great Plains Cliff and Outcrop Ecological System.
Diagnostic Characteristics
Cliffs, Bluffs, Rock Outcrops, Bedrock, Sparsely-Vegetated; Shallow and/or Poorly Developed Soils; Sandstone or Limestone Parent Material; <10% Vascular Plant Cover; Great Plains Region
Similar Systems
Range
This group is scattered throughout the Great Plains region of eastern and central Montana.
In MT, G567 occurs in Level III Ecoregions 42 (Northwestern Glaciated Plains) and 43 (Northwestern Great Plains).
In MT, G567 occurs in these Major Land Resource Areas: 46 - Northern and Central Rocky Mountain Foothills, 52-Brown Glaciated Plains, 53A-Northern Dark Brown Glaciated Plains, 58A,B,C,D-Northern Rolling High Plains, and 60B - Pierre Shale Plains.
Density and Distribution
Based on 2025 land cover layer. Grid on map is based on USGS 7.5 minute quadrangle map boundaries.
Mapped Distribution by County
Big Horn, Blaine, Carbon, Carter, Cascade, Chouteau, Custer, Daniels, Dawson, Fallon, Fergus, Gallatin, Garfield, Glacier, Golden Valley, Hill, Judith Basin, Lewis and Clark, Liberty, Mccone, Meagher, Musselshell, Park, Petroleum, Phillips, Pondera, Powder River, Prairie, Richland, Roosevelt, Rosebud, Sheridan, Stillwater, Sweet Grass, Teton, Toole, Treasure, Valley, Wheatland, Wibaux, Yellowstone
Based on 2025 land cover layer.
Spatial Pattern
Small Patch
Environment
This group is composed of cliffs and rock outcrops derived from limestone and sandstone parent materials throughout the Great Plains region in Montana. Landforms such as buttes, mesas, and eroded cliff bands constitute the major landforms. It is found within an arid to semi-arid climate. Parent material and erosional forces are the primary factors influencing their development. Pockets of soil develop below the cliff faces and in cracks and crevices. Plants in the shallow soils 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 provide a unique environment for plants adapted to these conditions (Graham & Knight 2004). Precipitation ranges from 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.
Vegetation
Vegetation is this group is typically sparse. Trees and shrubs if any are typically short, and mixedgrass species dominate the herbaceous stratum. This group has scattered vascular species found in cracks, depressions, or ledges in the bedrock where some soil can accumulate. Dominant species vary greatly depending on geology of the bedrock, climate, aspect, slope, and slope position. Grass species such as sideoats grama (Bouteloua curtipendula), blue grama (Bouteloua gracilis), prairie sandreed (Calamovilfa longifolia), bluebunch wheatgrass (Elymus spicatus), and Indian ricegrass (Oryzopsis hymenoides) are frequent at some sites. Creeping Juniper (Juniperus horizontalis), Common Juniper (Juniperus communis) and Kinnikinnick (Arctostaphylos uva-ursi) are frequent shrubs and sub-shrubs. Forbs present at these sites are diverse but include Buckwheats (Eriogonum sp), Broom Snakeweed (Gutierrezia sarothrae), Sandworts (Arenaria sp), Bladderpods (Physaria sp), Evening-primrose (Oenothera cespitosa), Stemless Four-nerve-daisy (Tetraneuris acaulis) and Penstemons (Penstemon species). Nonvascular species, especially lichens, may be common on exposed rock.
In Montana, this primarily rock outcrop group includes 1 Alliance and 1 Association within the National Vegetation Classification.
National Vegetation Classification
Download the complete NVC hierarchy for Montana
TT4 B04 Temperate-Boreal Grassland and Shrubland
TT4.d S60 Temperate-Boreal Open Rock
TT4.d1 F120 Temperate-Boreal Cliff and Rock Outcrop
TT4.d1.Na D051 Eastern North American Temperate Cliff, Scree and Rock
TT4.d1.Na.2 M116 Great Plains Cliff, Scree and Rock
TT4.d1.Na.2.a G567 Great Plains Cliff, Scree and Rock
A3981 Great Plains Acidic Cliff Alliance
CEGL002290 Sandstone Great Plains Xeric Butte - Bluff Sparse Vegetation
*Disclaimer: Some Alliances and Associations are considered provisional. Some require further documentation to verify their occurrence in the state
and some may be modified or deleted in future revisions after collection of additional data and information.
Dynamic Processes
These rock-dominated and sparsely-vegetated communities are influenced by the type of parent rock, elevation, aspect, climate, and both physical and chemical weathering patterns. Erosional and depositional processes are locally important. All of these processes and characteristics can have a strong influence over which species occur within these habitats (Larson et al 2000).
Management
This type is generally not a focus for management or restoration activities. Avoiding or preventing impacts to areas within this type, particularly those that support rare taxa or Species of Concern is the primary means of management.
Restoration Considerations
See Management Section.
Species Associated with this Community
- How Lists Were Created and Suggested Uses and Limitations
Animal Species Associations
Please note that while all vertebrate species have been systematically associated with vegetation communities, only a handful of invertebrate species have been associated with vegetation communities and invertebrates lists for each vegetation community should be regarded as incomplete. Animal species associations with natural vegetation communities that they regularly breed or overwinter in or migrate through were made by:
- 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, Werner et al. 2004, Adams 2003, and Foresman 2012);
- Evaluating structural characteristics and distribution of each vegetation community relative to the species' range and habitat requirements;
- Examining the observation records for each species in the state-wide point observation database associated with each vegetation community;
- Calculating the percentage of observations associated with each vegetation community relative to the percent of Montana covered by each vegetation community 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. Species that only migrate through Montana were only evaluated for migratory habitat use. In general, species are listed as associated with a vegetation community if it contains structural characteristics known to be used by the species. However, species are not listed as associated with a vegetation community if we found no support in the literature for the species’ use of structural characteristics of the community even if point observations were associated with it. If you have any questions or comments on animal species associations with vegetation communities, please contact the Montana Natural Heritage Program's Senior Zoologist.
Plant Species Associations
Please note that while diagnostic, dominant, or codominant vascular plant species for a vegetation community have been systematically assigned to those communities and vascular plant Species of Concern were systematically evaluated for their associations with vegetation communities, the majority of Montana’s vascular plant species have not been evaluated for their associations with vegetation communities and no attempt has been made to associate non-vascular plants, fungi, or lichens with vegetation communities. Plant species associations with natural vegetation communities were made in a manner similar to that described above for animals, but with review of Lesica et al. (2022) and specimen collection data from the Consortium of Pacific Northwest Herbaria. If you have any questions or comments on plant species associations with vegetation communities, please contact the Montana Natural Heritage Program's Program Botanist.
Suggested Uses and Limitations
Species associations with vegetation communities 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 or predicted habitat suitability models (this information can be requested at: https://mtnhp.mt.gov/requests/), or systematic surveys for species and onsite evaluations of habitat by trained biologists. Users of this information should be aware that the land cover data used to generate species associations is based on satellite imagery from 2016 and was only intended to be used at broader landscape scales. Land cover mapping accuracy is particularly problematic when the vegetation communities 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 vegetation community within its known geographic range, portions of that vegetation community 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.
- Consortium of Pacific Northwest Herbaria. https://www.pnwherbaria.org/ Last accessed May 30, 2025.
- 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.
- Lesica P., M. Lavin, and P.F. Stickney. 2022. Manual of vascular plants, 2nd Edition. Brit Press. 779 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.
- Species of Concern Associated with this Community
Vascular Plants
Mammals
Birds
Reptiles
Invertebrates
Original Concept Authors
J. Drake 2015
Montana Version Authors
S. Mincemoyer, E. Luther, S.V. Cooper, T. Luna, L. Vance
Version Date
12/5/2024
References
- Literature Cited AboveLegend:
View Online Publication
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
- Larson, D. W., U. Matthes, J. A. Gerrath, N. W. K. Larson, J. M. Gerrath, J. C. Nekola, G. L. Walker, S. Porembski, and A. Charlton. 2000. "Evidence for the Widespread Occurrence of Ancient Forests on Cliffs". Journal of Biogeography. 27 (2): 319-331.
- Web Search Engines for Articles on "Great Plains Cliff, Scree & Rock Vegetation"
