Roadless Areas
Home/Ecosystems/ Great Basin & Intermountain Introduced Perennial Grassland and Forbland

Great Basin & Intermountain Introduced Perennial Grassland and Forbland

EVT 9309
HerbExotic herbaceous
Roadless Areas (60)

Inventoried Roadless Areas where this ecosystem is present, identified from LANDFIRE 2024 Existing Vegetation Type spatial analysis. Coverage indicates the proportion of each area occupied by this ecosystem type.

California (1)

AreaForestCoverageHectares
Iceberg - SlinkardHumboldt-Toiyabe National Forest2.6%16.2

Nevada (23)

AreaForestCoverageHectares
Humboldt - RockwallHumboldt-Toiyabe National Forest28.6%21.6
Humboldt - LizziesHumboldt-Toiyabe National Forest13.5%3.78
Humboldt - WinchellHumboldt-Toiyabe National Forest10.5%54.18
Humboldt - North Fk.Humboldt-Toiyabe National Forest10.2%5.76
Humboldt - WisemanHumboldt-Toiyabe National Forest9.6%17.91
Humboldt - 2nd BoulderHumboldt-Toiyabe National Forest5.8%5.4
Humboldt - Hall CrHumboldt-Toiyabe National Forest4.2%7.29
Ruby - MarshHumboldt-Toiyabe National Forest3.7%152.73
Ruby - ThompsonHumboldt-Toiyabe National Forest3.3%71.1
Santa RosaHumboldt-Toiyabe National Forest2.5%546.93
Ruby - SouthHumboldt-Toiyabe National Forest2.5%130.95
Cabin CreekHumboldt-Toiyabe National Forest2.2%96.03
Ruby - Secret Pk.Humboldt-Toiyabe National Forest2.2%59.94
Pearl PeakHumboldt-Toiyabe National Forest2.1%616.41
Hot Springs ButteHumboldt-Toiyabe National Forest1.9%59.04
Pine Mtn.Humboldt-Toiyabe National Forest1.6%83.61
Ruby - SegundaHumboldt-Toiyabe National Forest1.1%56.34
Staunton RidgeHumboldt-Toiyabe National Forest1.0%42.21
ButtermilkHumboldt-Toiyabe National Forest1.0%78.3
Pennsylvania HillHumboldt-Toiyabe National Forest0.9%30.24
Humboldt - SouthHumboldt-Toiyabe National Forest0.9%42.66
Copper Mtns.Humboldt-Toiyabe National Forest0.8%105.03
Ruby - Lamoille CynHumboldt-Toiyabe National Forest0.7%92.88

Oregon (4)

AreaForestCoverageHectares
Horseshoe RidgeUmatilla National Forest2.2%53.01
North Fork MalheurMalheur National Forest1.1%83.79
HellholeUmatilla National Forest0.4%94.86
Lord Flat Somers PointWallowa-Whitman National Forest0.3%84.69

Utah (29)

AreaForestCoverageHectares
CopleysFishlake National Forest2.8%134.1
Stansbury MountainsWasatch-Cache National Forest1.7%267.57
0401023Ashley National Forest1.4%46.89
Upper South ForkWasatch-Cache National Forest1.4%94.32
Boulder MountainWasatch-Cache National Forest1.3%47.43
418029Uinta National Forest1.3%83.07
418022Uinta National Forest1.2%87.12
418012Uinta National Forest1.2%125.82
Mt. Logan SouthWasatch-Cache National Forest1.2%82.62
White KnollManti-Lasal National Forest1.1%62.28
418019Uinta National Forest1.1%29.97
418013Uinta National Forest1.0%58.95
Right Hand Fork LoganWasatch-Cache National Forest1.0%60.21
PavantFishlake National Forest0.9%151.92
418027Uinta National Forest0.8%43.29
Mahogany RangeWasatch-Cache National Forest0.8%35.19
418016Uinta National Forest0.7%103.95
Big Bear CreekManti-Lasal National Forest0.7%80.37
Oak CreekFishlake National Forest0.6%135.18
418015Uinta National Forest0.6%42.12
Mt. NaomiWasatch-Cache National Forest0.6%101.52
White MountainFishlake National Forest0.6%56.79
Circleville MountainFishlake National Forest0.6%55.62
SanpitchManti-Lasal National Forest0.6%65.97
North PavantFishlake National Forest0.5%117
Levan PeakManti-Lasal National Forest0.5%48.24
418028Uinta National Forest0.5%73.44
Dairy ForkManti-Lasal National Forest0.5%62.19
Moody WashDixie National Forest0.5%63.54

Wyoming (3)

AreaForestCoverageHectares
Illinois CreekMedicine Bow-Routt National Forest6.2%169.56
Platte River AdditionMedicine Bow-Routt National Forest3.4%110.25
Bear MountainMedicine Bow-Routt National Forest0.8%31.5
Methodology and Data Sources

Ecosystem classification: Ecosystems are classified using the LANDFIRE 2024 Existing Vegetation Type (EVT) layer, mapped to NatureServe Terrestrial Ecological Systems via a curated crosswalk. Each EVT is linked to the USNVC (U.S. National Vegetation Classification) hierarchy through pixel-level co-occurrence analysis of LANDFIRE EVT and NatureServe IVC Group rasters across all roadless areas.

Vegetation coverage: Coverage percentages and hectares are derived from zonal statistics of the LANDFIRE 2024 EVT raster intersected with roadless area boundaries.

Ecosystem narratives and community species: Sourced from the NatureServe Explorer API, representing professional ecological assessments of vegetation composition, environmental setting, dynamics, threats, and characteristic species assemblages.

IVC hierarchy: The International Vegetation Classification hierarchy is sourced from the USNVC v3.0 Catalog, providing the full classification from Biome through Association levels.

Component associations: Plant community associations listed as components of each NatureServe Ecological System. Association data from the NatureServe Explorer API.

State ranks: Conservation status ranks assigned by NatureServe member programs in each state where the ecosystem occurs.