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Montana Field Guides

Great Plains Sand Prairie

Provisional State Rank: S4
(see reason below)

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State Rank Reason
The land cover classification may overstate the range of true sand prairie, as silver sagebrush communities, which are widespread, are currently included in this system. If they were to be classified separately, the area of occupancy would decrease dramatically

General Description

The sand prairies constitute a very unique system within the western Great Plains. The unifying and controlling feature for this system is that coarse-textured soils predominate and the dominant grasses are well-adapted to this condition. In the northwestern portion of the system’s range, stand size corresponds to the area of exposed caprock sandstone, and small patches predominate, but larger patches are found embedded in the encompassing Great Plains Mixed Grass Prairie, and usually occupy higher positions in local landscapes where former caprock formations have eroded into more subdued and planar topography. In most of eastern Montana, substrates supporting this system have weathered in place from sandstone caprock. Soils can be relatively thin or deep due to varying amounts of downslope movement of weathered sands. Needle and thread (Hesperostipa comata) is the dominant grass species. Other frequent species include little bluestem (Schizachyrium scoparium), often occurring with threadleaf sedge (Carex filifolia) and dominating both sandy sites and actively eroding sites. Prairie sandreed (Calamovilfa longifolia), sand bluestem (Andropogon hallii) and big bluestem (Andropogon gerardii) are sporadically distributed and found generally on the coarsest-textured sands. Other graminoids include bluebunch wheatgrass (Pseudoroegneria spicata), sun sedge (Carex inops ssp. heliophila), and purple threeawn (Aristida purpurea). Characteristic forbs differ by occurrence, but species of scurf pea (Psoralidium species) and Indian breadroot (Pediomelum) species are common. Communities of silver sage (Artemisia cana ssp. cana) or skunkbush sumac (Rhus trilobata) can occur within this system. Wind erosion, fire and grazing constitute the other major dynamic processes that can influence this system.

Diagnostic Characteristics

herbaceous, lowland, sand soil texture, Calamovilfa longifolia, Hesperostipa comata

Similar Systems

This system is found throughout the Western Great Plains. The largest and most intact example of this system is found within the Sandhills region of Nebraska and South Dakota. However, it is also common (though occurring in predominantly small patches) farther west into central and eastern Montana. Small occurrences of this system are found even further west along the Rocky Mountain Front.

Ecological System Distribution
Approximately 10,305 square kilometers are classified as Great Plains Sand Prairie 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, Daniels, 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, Sheridan, Stillwater, Sweet Grass, Teton, Toole, Treasure, Valley, Wheatland, Wibaux, Yellowstone

Spatial Pattern
Large or Small Patch


The distribution, species richness and productivity of plant species within the sand prairie ecological system are controlled primarily by environmental conditions, in particular the temporal and spatial distribution of soil moisture and topography. Soils in the sand prairies can be relatively undeveloped and are highly permeable. Soil texture and drainage, along with a species' rooting morphology, photosynthetic physiology, and mechanisms to avoid transpiration loss, determine the composition and distribution of communities/associations within the sand prairies. Soils are also susceptible to wind erosion. Blowouts and sand draws are some of the unique wind-driven disturbances in the sand prairies, which can profoundly impact vegetation composition and succession within this system. In most of eastern Montana, substrates supporting this system have weathered in place from sandstone caprock; thus the solum is relatively thin, and the wind-sculpted features that are present further east, particularly in Nebraska, do not develop. Graminoid species dominate the sand prairies, although relative dominance can change due to impacts of wind disturbance.

This system is found primarily on sandy and sandy loam soils, generally in areas with a rolling topography, although it can occur on ridges, midslopes and/or lowland areas within a region. In Montana, occurrences are associated with the Great Plains Mixed Grass Prairie, usually occupying higher positions in local landscapes, because sandy members of predominantly marine shale formations constitute the highest and most weathering-resistant points in the landscape.


Needle and thread is the dominant graminoid within this system, regardless of disturbance, and is found on sands and, to a lesser extent. on sandy loams. This species increases in cover with disturbance relative to other graminoids. Prairie sandreed is the only other robust graminoid occurring in abundance and is usually associated with the coarse-textured substrates, becoming nearly a monospecific dominant on sands. Other graminoids such as sun sedge, threadleaf sedge, sand bluestem, little bluestem and big bluestem may be present. Big bluestem and sand bluestem are found only as small patch occurrences in easternmost Montana. Little bluestem occurs preferentially on sites derived from sandstone or porcellanite.

Many of the warm-season graminoids such as western wheatgrass (Pascopyrum smithii), blue grama (Bouteloua gracilis), Sandberg’s bluegrass (Poa secunda), prairie junegrass (Koeleria macrantha) and threadleaf sedge extend to the Rocky Mountain Front occurrences as dominant components on appropriate sites or as a response to disturbance (Kudray and Cooper 2006).

Characteristic forbs differ by region, but species of scurf pea and Indian breadroot are common. Narrowleaf purple coneflower (Echinacea angustifolia) can occur on sandy sites. Very diffuse patches of skunkbush sumac andhorizontal juniper (Juniperus horizontalis) are found on shallow sandy soils, often associated with breaklands. Other shrubs occasionally found within this system include silver sage. Soapweed yucca (Yucca glauca) occurs on sandy upland sites and bottomlands, but usually with less than 15 % cover. In some cases, Wyoming big sagebrush (Artemisia tridentata ssp. wyomingensis) occurs within or adjacent to this system.

National Vegetation Classification Switch to Full NVC View

Adapted from US National Vegetation Classification

A1193 Andropogon hallii Sand Prairie Alliance
CEGL001466 Andropogon hallii / Carex inops ssp. Heliophila Grassland
CEGL001467 Andropogon hallii / Calamovilfa longifolia Grassland
A1201 Calamovilfa longifolia Sand Prairie Alliance
CEGL001457 Rhus trilobata / Calamovilfa longifolia Shrub Grassland
CEGL001471 Calamovilfa longifolia / Carex inops ssp. Heliophila Grassland
CEGL001473 Calamovilfa longifolia / Hesperostipa comata Grassland
A1262 Achnatherum hymenoides - Pseudoroegneria spicata - Muhlenbergia pungens Grassland Alliance
CEGL001674 Pseudoroegneria spicata / Achnatherum hymenoides Grassland
A1540 Yucca glauca Prairie Scrub Alliance
CEGL002675 Yucca glauca - Calamovilfa longifolia Shrub Grassland
A3586 Artemisia cana ssp. Cana Wet Shrubland Alliance
CEGL001553 Artemisia cana ssp. cana - Hesperostipa comata Shrub Wet Meadow
A3964 Rhus glabra - Rhus trilobata Central Rocky Mountain Montane-Foothill Shrubland Alliance
CEGL001120 Rhus trilobata - Pseudoroegneria spicata Shrub Grassland
A3987 Festuca idahoensis - Pseudoroegneria spicata - Poa secunda Dry Grassland Alliance
CEGL001679 Pseudoroegneria spicata / Hesperostipa comata Grassland
A4028 Andropogon gerardii - Sorghastrum nutans Mixedgrass Western Plains Grassland Alliance
A4033 Hesperostipa comata Northwestern Great Plains Grassland Alliance
CEGL001700 Hesperostipa comata / Carex filifolia Grassland
CEGL002037 Hesperostipa comata / Bouteloua gracilis / Carex filifolia Grassland
*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
The distribution, species richness and productivity of plant species within the sand prairie ecological system are controlled primarily by environmental conditions, in particular the temporal and spatial distribution of soil moisture and topography. Another important aspect of this system is its susceptibility to wind erosion. Blowouts and sand draws can impact vegetation composition and succession within this system; fire and grazing constitute the other major disturbances. Overgrazing, fire and trampling that leads to the removal of vegetation in areas susceptible to blowouts can either instigate a blowout or perpetuate blowouts occurring within the system. Overgrazing can also lead to significant erosion.

Grazing should be managed to avoid instigation and perpetuation of blowouts and vegetation loss within this system. Prescribed fires can also be used to enhance, maintain and restore this system.

Restoration Considerations
In addition to reestablishing ecological processes such as prescribed fire, some restoration sites may require the reintroduction of native dominant grass species such as prairie sandreed, sand bluestem and needle and thread. Restoration efforts should utilize seed sources collected from nearby sand prairie remnants to augment and maintain genetic diversity of isolated, remnant plant populations.

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
T. Luna and L.K. Vance

Version Date

  • Classification and Map Identifiers

    Cowardin Wetland Classification: Not applicable

    NatureServe Identifiers:
    Element Global ID 28527
    System Code CES303.670, Western Great Plains Sand Prairie

    National Land Cover Dataset:
    71: Grassland/Herbaceous

    7121: Western Great Plains Sand Prairie

  • Additional ReferencesLegend:   View Online Publication
    Do you know of a citation we're missing?
    • Erickson, Albert W., and D. B. Siniff. 1963. A statistical evaluation of factors influencing aerial survey results on brown bears. Anchorage, Alaska: Alaska Department of Fish and Game.

    • Breckenridge, W. J. 1944. Reptiles and Amphibians of Minnesota. Univ. Minnesota Press, Minneapolis. 202 pp.
    • Comer, P. (editor), L. Allen, S. Cooper, D. Faber-Langendoen, and G. Jones. 1999. Selected shrubland and grassland communities of the northern Great Plains. Report to the Nebraska National Forest. The Nature Conservancy.
    • Kudray, G.M. and S.V. Cooper. 2006. Montana's Rocky Mountain Front: Vegetation Map and Type Descriptions. Report to the United States Fish and Wildlife Service. Montana Natural Heritage Program, Helena, Montana. 26 pp. plus appendices.

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Citation for data on this website:
Great Plains Sand Prairie — Western Great Plains Sand Prairie.  Montana Field Guide.  Retrieved on , from