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Montana Field Guide

Montana Field Guides

Rocky Mountain Lower Montane, Foothill, and Valley Grassland

Provisional State Rank: S4

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General Description

This grassland system of the northern Rocky Mountains is found at lower montane to foothill elevations in mountains and valleys throughout Montana. These grasslands are floristically similar to Big Sagebrush Steppe but are defined by shorter summers, colder winters, and young soils derived from recent glacial and alluvial material. They are found at elevations from 548 - 1,650 meters (1,800-5,413 feet). In the lower montane zone, they range from small meadows to large open parks surrounded by conifers; below the lower treeline, they occur as extensive foothill and valley grasslands. Soils are relatively deep, fine-textured, often with coarse fragments, and non-saline. Microphytic crust may be present in high-quality occurrences. This system is typified by cool-season perennial bunch grasses and forbs (>25%) cover, with a sparse shrub cover (<10%). Rough fescue (Festuca campestris) is dominant in the northwestern portion of the state and Idaho fescue (Festuca idahoensis) is dominant or co-dominant throughout the range of the system. Bluebunch wheatgrass (Pseudoroegneria spicata) occurs as a co-dominant throughout the range as well, especially on xeric sites. Western wheatgrass (Pascopyrum smithii) is consistently present, often with appreciable coverage (>10%) in lower elevation occurrences in western Montana and virtually always present, with relatively high coverages (>25%), on the edge of the Northwestern Great Plains region. Species diversity ranges from a high of more than 50 per 400 square meter plot on mesic sites to 15 (or fewer) on xeric and disturbed sites. Most occurrences have at least 25 vascular species present. Farmland conversion, noxious species invasion, fire suppression, heavy grazing and oil and gas development are major threats to this system.

Diagnostic Characteristics
Cool season bunchgrasses, foothill and montane elevations, ustic, loam to silt soils, herbaceous cover greater than 25%, shrub cover less than 10%, graminoid cover greater than 25%

Similar Systems

In Montana, this system is found in the Bitterroot, Missoula, Mission, and Flathead valleys of western Montana, the North Fork of the Flathead River in Glacier National Park and the Tobacco Plains north of Eureka in northwestern Montana. East of the Continental Divide, this system in well represented on the Blackfeet Indian Reservation from the Alberta border and at lower elevations along the eastern edge of Glacier National Park south along the Rocky Mountain Front to west-central Montana and east to island mountain ranges. It also occurs in the Northwestern Great Plains of Montana at the highest elevations, generally above 1280 meters (4,200 feet) on mesas, buttes and high plateaus. In its broader geographic range, it occurs throughout the southern interior and southern portion of the Fraser Plateau, as well as the valleys around the Fraser River in the Pavilion Ranges, the Nicola River, and the Similkameen River in British Columbia, northwestern Wyoming, and west through Idaho into the Blue Mountains of northeastern Oregon.

Ecological System Distribution
Approximately 20,315 square kilometers are classified as Rocky Mountain Lower Montane, Foothill, and Valley Grassland in the 2017 Montana Land Cover layers.  Grid on map is based on USGS 7.5 minute quadrangle map boundaries.

Montana Counties of Occurrence
Beaverhead, Big Horn, Blaine, Broadwater, Carbon, Cascade, Chouteau, Deer Lodge, Fergus, Flathead, Gallatin, Glacier, Golden Valley, Granite, Hill, Jefferson, Judith Basin, Lake, Lewis and Clark, Liberty, Lincoln, Madison, Meagher, Mineral, Missoula, Musselshell, Park, Phillips, Pondera, Powder River, Powell, Ravalli, Rosebud, Sanders, Silver Bow, Stillwater, Sweet Grass, Teton, Toole, Valley, Wheatland, Yellowstone

Spatial Pattern
Large patch


This fescue-dominated grassland is transitional between the mixed grass prairie and montane/subalpine grasslands occurring adjacent to or within forested habitats. In northern Montana, it is often associated with aspen parkland. Rough fescue (Festuca campestris) and Idaho fescue (Festuca idahoensis) are the dominants in northwestern Montana. To the west, this system grades into Palouse prairie in northern Idaho and contains many of the same species. Average precipitation ranges from 292-406 millimeters (11.5 to 16.5 inches). Mean temperatures increase on the eastern edge of this system. Where it occurs within glaciated landscapes, numerous pothole wetlands and other wetland systems are found, often characterized by a perimeter of willow (Salix species).

In northwestern and west-central Montana, this ecosystem forms in openings in Douglas-fir (Pseudotsuga menziesii) and ponderosa pine (Pinus ponderosa) forests, and in intermountain and mountain valleys and big sagebrush (Artemisia tridentata) shrublands. East of the Continental Divide, this system is found along valley bottoms and steep canyon slopes at montane elevations along the Rocky Mountain Front to west-central Montana. Rolling uplands and undulating plains are typical topography east of the Continental Divide, from the Alberta border south along the Rocky Mountain Front and east where this system merges with mixed prairie grassland. Much of this area is cultivated. Black Chernozems are the dominant soils, reflecting moister, cooler conditions and the incorporation of relatively high amounts of organic matter.


In Montana, two plant communities dominate this system: 1) Rough Fescue - Idaho Fescue, found on moister sites such as the north- and east-facing slopes in foothills and swales in the northwestern edge of the Great Plains and valley bottoms with deeper soils; and 2) Bluebunch Wheatgrass - Idaho Fescue, found on drier sites such as ridges, hilltops, and south- and west-facing slopes in the foothills and on level sites with sharply drained glacial-till soils.

On pristine, moist sites, rough fescue can form a nearly continuous cover, interspersed with Idaho fescue and the rhizomatous ecotype of bluebunch wheatgrass. Other graminoids include western needlegrass (Achnatherum occidentale), Richardson’s needlegrass (Achnatherum richardsonii), oatgrass (Danthonia species), prairie junegrass (Koeleria macrantha), Sandberg’s bluegrass (Poa secunda), western wheatgrass (Pascopyrum smithii), thickspike wheatgrass (Elymus lanceolatus), basin wildrye (Leymus cinereus), and Liddon sedge (Carex petasata). These moister sites support a forb- rich community that includes species such as arrowleaf balsamroot (Balsamorhiza sagittata), yarrow (Achillea millefolium), silky lupine (Lupinus sericeus), sticky geranium (Geranium viscossisimum), nine-leaf biscuitroot (Lomatium triternatum), sticky cinquefoil (Potentilla glandulosa), prairie cinquefoil (Potentilla gracilis), sulphur penstemon (Penstemon confertus), little larkspur (Delphinium bicolor), crazyweed (Oxytropis species), prairie gentian (Gentiana affinis), wild strawberry (Fragaria virginiana), and Indian paintbrush (Castilleja species).

Shrub cover is usually less than 10 percent and includes species such as shrubby cinquefoil (Dasiphora fruticosa), Woods’ rose (Rosa woodsii), snowberry (Symphoricarpos species), and common juniper (Juniperus communis). Serviceberry (Amelanchier alnifolia), Douglas hawthorn (Crataegus douglasii), and common chokecherry (Prunus virginiana) often occur as patches on north-facing slopes of foothills where snow persists longer into the growing season.

On drier sites dominated by Idaho fescue and the bunchgrass ecotype of bluebunch wheatgrass, common forbs include yarrow, Indian blanketflower (Gaillardia aristata), boreal bedstraw (Galium boreale), prairie smoke (Geum triflorum), prairie arnica (Arnica sororia), rosy pussytoes (Antennaria microphylla), prairie cinquefoil, silver lupine (Lupinus argenteus), silky lupine,early biscuitroot (Lomatium macrocarpum), alyssum leaf phlox (Phlox alyssifolia), Hood’s phlox (Phlox hoodii), gayfeather (Liatris punctata), stoneseed (Lithospermum ruderale), buckwheat (Eriogonum species), fuzzytongue penstemon (Penstemon eriantherus), Missouri goldenrod (Solidago missouriensis), crazyweed (Oxytropis species), alumroot (Huechera species), prairie crocus (Pulsatilla patens), brittle prickly pear (Opuntia fragilis), western sagewort (Artemisia ludoviciana), boreal sagewort (Artemisia frigida), and daisy (Erigeron species). Endemic species are common in drier, rocky sites along the northwestern edge of the Great Plains, e.g., Rocky Mountain douglasia (Douglasia montana), shining penstemon (Penstemon nitidus), and Alberta penstemon (Penstemon albertinus). Other graminoids present within this drier community includetimber oatgrass (Danthonia intermedia), prairie junegrass (Koeleria macrantha), Sandberg’s bluegrass (Poa secunda), Indian ricegrass (Achnatherum hymenoides), Geyer’s sedge (Carex geyeri), andthreadleaf sedge (Carex filifolia). Lesser spikemoss (Selaginella densa) may be present in high cover on some sites. Lichen cover can be high on ungrazed occurrences (Antos et al,1983) or where fire has been suppressed. Moss can be variable, depending on level of disturbance.

National Vegetation Classification Switch to Full NVC View

Adapted from US National Vegetation Classification

A2658 Elymus repens Ruderal Grassland Alliance
CEGL005868 Elymus repens Ruderal Grassland
A3965 Festuca idahoensis - Carex scirpoidea - Danthonia intermedia Central Rocky Mountain Subalpine Dry Grassland Alliance
CEGL001897 Festuca idahoensis Grassland
A3966 Festuca idahoensis - Calamagrostis rubescens - Achnatherum nelsonii Central Rocky Mountain Montane Mesic Grassland Alliance
CEGL001625 Festuca idahoensis / Achnatherum richardsonii Grassland
CEGL001898 Festuca idahoensis / Carex filifolia Grassland
CEGL005860 Achnatherum nelsonii / Lupinus sericeus Grassland
CEGL005862 Calamagrostis rubescens Grassland
A3986 Festuca campestris - Festuca idahoensis Mesic Grassland Alliance
CEGL001629 Festuca campestris / Pseudoroegneria spicata Grassland
CEGL005869 Festuca campestris / (Festuca idahoensis) / Achnatherum richardsonii Grassland
CEGL005870 Festuca campestris / Festuca idahoensis / Geranium viscosissimum Grassland
CEGL005875 Festuca campestris / Festuca idahoensis Grassland
A3987 Festuca idahoensis - Pseudoroegneria spicata - Poa secunda Dry Grassland Alliance
CEGL001624 Festuca idahoensis / Pseudoroegneria spicata Grassland
CEGL001665 Pseudoroegneria spicata / Carex filifolia Grassland
A3988 Festuca idahoensis - Pseudoroegneria spicata - Pascopyrum smithii Mesic Grassland Alliance
CEGL001621 Festuca idahoensis / Pascopyrum smithii Grassland
A4052 Ephedra spp. - Leymus salinus - Eriogonum corymbosum Badlands Cold Desert Sparse Vegetation Alliance
CEGL005874 Phleum pratense / Poa pratensis / Bromus inermis Ruderal 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

Shrubs may increase following heavy grazing and/or with fire suppression. Rough fescue is highly palatable throughout the grazing season. Summer overgrazing for 2 to 3 years can result in rough fescue loss. In one study, although a light stocking rate for 32 years did not affect range condition, a modest increase in stocking rate led to a marked decline in range condition (Willms and Rhode, 1998). Oatgrass tends to replace rough fescue under moderate or heavy grazing pressure. Long-term heavy grazing on moister sites can result in a shift to a Kentucky bluegrass (Poa pratensis)/timothy(Phleum pratense)/ smooth brome (Bromus inermis) type.

In Montana, many exotic species invaded these grasslands, and in some cases have completely replaced native species. On disturbed, drier sites, Japanese brome (Bromus japonicus), sulfur cinquefoil (Potentilla recta), leafy spurge (Euphorbia esula), spotted knapweed (Centaurea biebersteinii), Saint John’s wort (Hypericum perforatum), and whitetop (Cardaria draba) are common. Mesic sites are threatened by meadow hawkweed complex (Hieracium pratense, H.floribundum, H.piloselliodes), orange hawkweed (Hieracium aurantiacum), ox-eye daisy (Leucanthemum vulgare), tall buttercup (Ranunculus acris) and Canada thistle (Cirsium arvense).

In the absence of natural fire, periodic prescribed burns can be used to maintain this system.

Restoration Considerations

Restoration strategies will depend largely on disturbance severity.Modified grazing practices can allow this system to recover without additional restoration needs. Antos and others (1983) have suggested prescribed fires at intervals of every 5 to 10 years for sites in western Montana. Following burning and depending on fire intensity, rough fescue may recover at much slower rates than Idaho fescue (Antos et al., 1983). Short-term conditions after burning, e.g., precipitation and cold-stress days, appear important in controlling species responses and composition of plant communities (Gross and Romo, 2009).

On some sites, site preparation will require noxious species eradication and control for at least two seasons before and after restoration. On reclamation sites where soil preparation is required, soil disking techniques that discourage uniform soils and seed beds should be used. Feathering and smoothing topsoil may benefit invasive species such as Kentucky bluegrass (Poa pratensis) and smooth brome (Bromus inermis), while rough conditions may inhibit their growth, allowing rough fescue (Festuca campestris) and its associated grasses to establish more readily (Desserud, 2006).

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
R. Crawford, mod. M.S. Reid and G. Kittel

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

Version Date

  • Classification and Map Identifiers

    Cowardin Wetland Classification: Not applicable

    NatureServe Identifiers:
    Element Global ID
    System Code CES306.040, Northern Rocky Mountain Lower Montane, Foothill and Valley Grassland

    National Land Cover Dataset:
    71: Grassland/Herbaceous

    7112: Northern Rocky Mountain Lower Montane, Foothill and Valley Grassland

  • Additional ReferencesLegend:   View Online Publication
    Do you know of a citation we're missing?
    • Desserud, Peggy Ann. 2006. Restoration of rough fescue grassland on pipelines in southwestern Alberta. Lethbridge, Alta: Alberta Sustainable Resource Development, Rangeland Management Branch, Public Lands and Forests Division.

    • Antos, J. A., B. McCune, and C. Bara. 1983. The effect of fire on an ungrazed Western Montana grassland. American Midland Naturalist 110:354-364.
    • Gross, D. V., and J. T. Romo. 2010. "Temporal changes in species composition in Fescue Prairie: relationships with burning history, time of burning, and environmental conditions". Plant Ecology. 208 (1): 137-153.
    • Willms, Walter D., and Lyle M. Rode. 1998. "Forage Selection by Cattle on Fescue Prairie in Summer or Winter". Journal of Range Management. 51 (5).

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Citation for data on this website:
Rocky Mountain Lower Montane, Foothill, and Valley Grassland — Northern Rocky Mountain Lower Montane, Foothill and Valley Grassland.  Montana Field Guide.  Retrieved on , from