Natural Resources
Conservation Service
Ecological site R010XC068OR
SR Cool Mountain North
12-16 PZ
Last updated: 4/02/2025
Accessed: 04/20/2026
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Provisional. A provisional ecological site description has undergone quality control and quality assurance review. It contains a working state and transition model and enough information to identify the ecological site.
Associated sites
R010XC075OR SR Mountain Shallow North 12-16 PZ
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R010XC032OR SR Mountain 12-16 PZ
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SR Cool 12-16 PZ
R010XC037OR SR Mountain Shallow 12-16 PZ
SR Mountain Shallow 12-16 PZ
R010XC039OR SR Very Shallow 12-16 PZ
SR Very Shallow 12-16 PZ
R010XC047OR SR Mountain South 12-16 PZ
SR Mountain South 12-16 PZ
R010XC066OR SR Mountain North 12-16 PZ
SR Mountain North 12-16 PZ
Similar sites
R010XC075OR SR Mountain Shallow North 12-16 PZ
Mountain Shallow North 12-16" PZ (shallower soil, lower production)
R010XC066OR SR Mountain North 12-16 PZ
SR Mountain North 12-16 PZ (higher elevation, different composition -mountain big sagebrush strongly dominant big sagebrush)
Table 1. Dominant plant species
Tree Not specified
Shrub (1) Artemisia tridentata var. vaseyana
(2) Artemisia tridentata ssp. tridentataHerbaceous (1) Festuca idahoensis
Physiographic features
This site occurs on north aspects of terraces, tablelands and mountain plateaus. Slopes typically range from 12 to 60%. Elevations typically range from 3,500 to 4,500 feet.
Table 2. Representative physiographic features
Landforms (1) Terrace
(2) Plateau
Flooding frequency None Ponding frequency None Elevation 3500 – 4500 ft Slope 12 – 60 % Aspect N Climatic features
The annual precipitation ranges from 12 to 16 inches, most of which occurs in the form of snow during the months of November through March. Localized convection storms occasionally occur during the summer. The soil temperature regime is cool mesic to frigid with a mean air temperature of 45 degrees F.
Temperature extremes range from 90 to -30 degrees F. The frost free period ranges from less than 30 to 90 days. The optimum growth period for plant growth is May through July.
Table 3 Representative climatic features
Frost-free period (average) 90 days Freeze-free period (average) 100 days Precipitation total (average) 20 in BarLineFigure 1. Monthly precipitation range
BarLineFigure 2. Monthly average minimum and maximum temperature
">Influencing water features
Soil features
The soils of this site are typically moderately deep to deep and well drained. Typically, the surface layer is a silt loam to clay loam about 12 inches thick. The subsoil is a clay loam to clay about 22 inches. Depth to an indurated pan or bedrock ranges from 20 to 60 inches. Permeability is moderate. The available water holding capacity (AWC) is about 6 to 10 inches for the profile. The erosion potential is moderate to severe.
Table 4. Representative soil features
Surface texture (1) Silt loam
(2) Stony clay loam
Family particle size (1) Clayey
Drainage class Well drained Permeability class Moderate to slow Soil depth 20 – 60 in Surface fragment cover <=3" Not specified Surface fragment cover >3" 0 – 10 % Available water capacity
(0-40in)6 – 10 in Calcium carbonate equivalent
(0-40in)Not specified Electrical conductivity
(0-40in)Not specified Sodium adsorption ratio
(0-40in)Not specified Subsurface fragment volume <=3"
(Depth not specified)9 – 20 % Subsurface fragment volume >3"
(Depth not specified)0 – 20 % Ecological dynamics
The potential native plant community is strongly dominated by Idaho fescue. Mountain big sagebrush is common. Xeric big sagebrush and basin big sagebrush are common. Wild crab apple and antelope bitterbrush occur sporadically. Bluebunch wheatgrass, Sandberg bluegrass and a variety of forbs are present. Vegetative composition of the community is approximately 80 percent grasses, 10 percent forbs and 10 percent shrubs. Approximate ground cover is 80 to 90 percent (basal and crown).
Range in Characteristics:
Idaho fescue is strongly dominant on north facing aspects. Bluebunch wheatgrass increases as the aspect changes to the east or northwest. Mountain big sagebrush increases in relationship to xeric and basin big sagebrush with elevation. Deciduous shrubs increase at the upper end of the precipitation zone and over gravelly and fractured substratums. Production increases with soil depth and precipitation.
Disturbance Response:
If the condition of the site deteriorates as a result of overgrazing, Idaho fescue decreases while bluebunch wheatgrass increases. Big sagebrush (mountain, basin & xeric) rapidly increases and juniper invades from higher elevation rock outcrops. With continued overgrazing big sagebrush and juniper dominate the overstory and Sandberg bluegrass, a shallow rooted perennial dominates the understory. Annual invasion is limited unless ground disturbance occurs. With further deterioration and lack of fire juniper invasion continues, shrubs decrease and bare ground increases. With fire and heavy use or ground disturbance, annuals and Sandberg or bulbous bluegrass increase. Bare ground increases and excessive erosion contributes to downstream sedimentation.
States: ARTRV-X-T/POSE-Bare Ground;JUOC/ARTRV-X-T/POSE-Bare Ground;POSE-POBU-Annuals-Bare Ground
Juniper Response:
Fine fuel reduction from improper grazing and fire suppression has led to an increase in the historical fire return interval on many western rangelands. A reduction in fire frequency on this site leads to an invasion of juniper, a decrease in sagebrush cover followed by a decrease in herbaceous cover and understory diversity. As juniper invades, sagebrush declines with a subsequent decrease in forbs, bluebunch wheatgrass and needlegrass. Idaho fescue becomes the primary herbaceous species occurring under the canopy of the juniper trees. Sandberg’s bluegrass increases in the plant community on lower elevation sites while bare ground increases in the interspaces between trees. Bitterbrush is more resistant to juniper encroachment than sagebrush and maintains its presence in the community, however vigor and fitness (seed production) may be thwarted.
The potential for soil erosion increases as the juniper woodland matures and the understory plant community cover declines. Excessive erosion in the bare soil interspaces markedly reduces the site productivity and contributes to downstream sedimentation. The combined effect of overgrazing and juniper invasion increases the rate of decline in ecological function and the probability of crossing a threshold is high.
Treatment Response:
This site responds positively to juniper removal if soil erosion is not significant. Seeding may be necessary if there are less than 1-2 bunchgrass plants per meter square in the understory.State and transition model
More interactive model formats are also available. View Interactive Models
Click on state and transition labels to scroll to the respective textEcosystem states
State 1 submodel, plant communities
State 1
ReferenceCommunity 1.1
Historical Climax Plant CommunityThe potential native plant community is strongly dominated by Idaho fescue. Mountain big sagebrush is common. Xeric big sagebrush and basin big sagebrush are common. Wild crab apple and antelope bitterbrush occur sporadically. Bluebunch wheatgrass, Sandberg bluegrass and a variety of forbs are present. Vegetative composition of the community is approximately 80 percent grasses, 10 percent forbs and 10 percent shrubs. Approximate ground cover is 80 to 90 percent (basal and crown).
Figure 3. Annual production by plant type (representative values) or group (midpoint values)
Table 5. Annual production by plant type
Plant type Low
(lb/acre)Representative value
(lb/acre)High
(lb/acre)Grass/Grasslike 960 1280 1760 Shrub/Vine 120 160 220 Forb 120 160 220 Total 1200 1600 2200 Additional community tables
Table 6. Community 1.1 plant community composition
Group Common name Symbol Scientific name Annual production () Foliar cover (%) Grass/Grasslike1 Dominant, perennial deep-rooted bunchgrass 960–1120 Idaho fescue FEID Festuca idahoensis 960–1120 – 2 Sub-dominant, perennial deep-rooted grass 160–320 bluebunch wheatgrass PSSPS Pseudoroegneria spicata ssp. spicata 160–320 – 5 Other perennial grasses 36–240 basin wildrye LECI4 Leymus cinereus 16–48 – Cusick's bluegrass POCU3 Poa cusickii 0–32 – western needlegrass ACOC3 Achnatherum occidentale 0–32 – threadleaf sedge CAFI Carex filifolia 0–32 – needle and thread HECO26 Hesperostipa comata 0–32 – prairie Junegrass KOMA Koeleria macrantha 10–32 – squirreltail ELEL5 Elymus elymoides 5–16 – Sandberg bluegrass POSE Poa secunda 5–16 – Forb7 Dominant, perennial forbs 80–160 arrowleaf balsamroot BASA3 Balsamorhiza sagittata 32–64 – parsnipflower buckwheat ERHE2 Eriogonum heracleoides 16–32 – lupine LUPIN Lupinus 16–32 – common yarrow ACMI2 Achillea millefolium 16–32 – 9 Other forbs 56–191 hawksbeard CREPI Crepis 5–16 – fleabane ERIGE2 Erigeron 5–16 – Scouler's woollyweed HISC2 Hieracium scouleri 5–16 – stoneseed LITHO3 Lithospermum 5–16 – desertparsley LOMAT Lomatium 5–16 – ragwort SENEC Senecio 5–16 – phlox PHLOX Phlox 5–10 – woodland-star LITHO2 Lithophragma 5–10 – Indian paintbrush CASTI2 Castilleja 5–10 – bastard toadflax COMAN Comandra 0–10 – agoseris AGOSE Agoseris 5–10 – onion ALLIU Allium 2–5 – brodiaea BRODI Brodiaea 2–5 – mariposa lily CALOC Calochortus 0–5 – bushy bird's beak CORA5 Cordylanthus ramosus 2–5 – larkspur DELPH Delphinium 2–5 – owl's-clover ORTHO Orthocarpus 0–5 – sagebrush buttercup RAGL Ranunculus glaberrimus 2–5 – stonecrop SEDUM Sedum 2–5 – deathcamas ZIGAD Zigadenus 2–5 – Shrub/Vine11 Dominant, evergreen shrubs 50–240 mountain big sagebrush ARTRV Artemisia tridentata ssp. vaseyana 48–128 – big sagebrush ARTRX Artemisia tridentata ssp. xericensis 32–80 – basin big sagebrush ARTRT Artemisia tridentata ssp. tridentata 32–80 – 13 Other shrubs 42–304 Saskatoon serviceberry AMAL2 Amelanchier alnifolia 0–32 – threetip sagebrush ARTR4 Artemisia tripartita 0–32 – yellow rabbitbrush CHVI8 Chrysothamnus viscidiflorus 16–32 – wild crab apple PERA4 Peraphyllum ramosissimum 0–32 – chokecherry PRVI Prunus virginiana 0–32 – antelope bitterbrush PUTR2 Purshia tridentata 0–32 – wax currant RICE Ribes cereum 16–32 – Woods' rose ROWO Rosa woodsii 10–32 – common snowberry SYAL Symphoricarpos albus 0–32 – littleleaf horsebrush TEGL Tetradymia glabrata 0–16 – Tree16 Dominant, evergreen trees 0–32 ponderosa pine PIPO Pinus ponderosa 0–16 – Interpretations
Animal community
Livestock Grazing:
This site is suitable for livestock grazing use in the late spring, summer, and fall under a planned grazing system. Use should be postponed until the soils are firm enough to prevent trampling damage and soil compaction. Grazing management should be keyed for Idaho fescue. Deferred grazing or rest is recommended at least once every three years.
Native Wildlife Associated with the Potential Climax Community:
This site is commonly used by mule deer, elk, antelope, rabbits, rodents, upland birds and various predators. It is a preferred site for upland bird nesting and rearing areas. Mule deer and elk make excellent use of the site for summer and late fall forage.
Hydrological functions
The soils of this site are typically in an upland topographic position. They have moderate high runoff potential and medium infiltration rates when the hydrologic cover is good. Under frozen ground conditions runoff potential is significantly increased. This occurs for extended periods when deep rooted perennial bunchgrass cover is negligible. Hydrologic cover is good when the Idaho fescue deep rooted bunchgrass component is >70 percent of potential.
Other information
Juniper invasion is a major risk on this site. Control measures include prescribed burning and/or cutting followed by rest to improve vigor, density and seed production of existing deep rooted perennial bunchgrasses. Consider seeding following control measures if an inadequate stand of bunchgrass is present.
Green rabbitbrush, when present, should be targeted in a herbicide brush control program. It can increase markedly.Supporting information
Contributors
A Bahn, G Kuehl, H Barrett
T.Bloomer, B.Gillaspy, E.Petersen, A.BahnApproval
Kirt Walstad, 4/02/2025
Rangeland health reference sheet
Interpreting Indicators of Rangeland Health is a qualitative assessment protocol used to determine ecosystem condition based on benchmark characteristics described in the Reference Sheet. A suite of 17 (or more) indicators are typically considered in an assessment. The ecological site(s) representative of an assessment location must be known prior to applying the protocol and must be verified based on soils and climate. Current plant community cannot be used to identify the ecological site.
Author(s)/participant(s) Jeff Repp and Bruce Frannsen Contact for lead author NRCS Oregon State Rangeland Management Specialist Date 04/24/2003 Approved by Approval date Composition (Indicators 10 and 12) based on Annual Production Indicators
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Number and extent of rills:
None to some -
Presence of water flow patterns:
None to some -
Number and height of erosional pedestals or terracettes:
None to very few (some frost heaving) -
Bare ground from Ecological Site Description or other studies (rock, litter, lichen, moss, plant canopy are not bare ground):
0-5% -
Number of gullies and erosion associated with gullies:
None -
Extent of wind scoured, blowouts and/or depositional areas:
None -
Amount of litter movement (describe size and distance expected to travel):
Fine - limited movement -
Soil surface (top few mm) resistance to erosion (stability values are averages - most sites will show a range of values):
Significantly resistant to erosion: aggregate stability = 5-6 -
Soil surface structure and SOM content (include type of structure and A-horizon color and thickness):
Weak fine granular to platy, to very fine subangular blocky structure, dry color value 4-5, 4-20 inches thick; Moderate OM (2-4%) -
Effect of community phase composition (relative proportion of different functional groups) and spatial distribution on infiltration and runoff:
Significant ground cover (80-90%) moderately to significnatly limit rainfall impact and overland flow on these gentle to steep slopes (12-80%) -
Presence and thickness of compaction layer (usually none; describe soil profile features which may be mistaken for compaction on this site):
None -
Functional/Structural Groups (list in order of descending dominance by above-ground annual-production or live foliar cover using symbols: >>, >, = to indicate much greater than, greater than, and equal to):
Dominant:
Deep-rooted, perennial, cool-season bunch-grassesSub-dominant:
Evergreen shrubs > deciduous shrubsOther:
Forbs >= other perennial grassesAdditional:
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Amount of plant mortality and decadence (include which functional groups are expected to show mortality or decadence):
Normal decadence and mortality expected -
Average percent litter cover (%) and depth ( in):
-
Expected annual annual-production (this is TOTAL above-ground annual-production, not just forage annual-production):
Favorable: 2200, Normal: 1600, Unfavorable: 1000 lbs/acre/year at high RSI -
Potential invasive (including noxious) species (native and non-native). List species which BOTH characterize degraded states and have the potential to become a dominant or co-dominant species on the ecological site if their future establishment and growth is not actively controlled by management interventions. Species that become dominant for only one to several years (e.g., short-term response to drought or wildfire) are not invasive plants. Note that unlike other indicators, we are describing what is NOT expected in the reference state for the ecological site:
Western Juniper readily invades the site. Cheatgrass and Medusahead invade sites that have lost deep rooted perennial grass functional groups -
Perennial plant reproductive capability:
All species should be capable of reproducing annually
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