Natural Resources
Conservation Service
Ecological site R058BY128WY
Lowland (LL) 10-14” PZ
Last updated: 9/15/2024
Accessed: 11/21/2024
General information
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.
Figure 1. Mapped extent
Areas shown in blue indicate the maximum mapped extent of this ecological site. Other ecological sites likely occur within the highlighted areas. It is also possible for this ecological site to occur outside of highlighted areas if detailed soil survey has not been completed or recently updated.
MLRA notes
Major Land Resource Area (MLRA): 058B–Northern Rolling High Plains, Southern Part
MLRA 58B is located in northeastern Wyoming (95 percent) and extreme southeastern Montana (5 percent). It is comprised of sedimentary plains, scoria hills, and river valleys. The major rivers include the Powder, Tongue, Belle Fourche, Cheyenne, and North Platte. Tributaries include the Little Powder River, Little Missouri River, Clear Creek, Crazy Woman Creek, and others. This MLRA is traversed by Interstates 25 and 90, and U.S. Highways 14 and 16. The extent of MLRA 58B covers approximately 12.3 million acres. Major land uses include rangeland (approximately 93 percent), cropland, pasture, and hayland (approximately 2 percent), and forest, urban, and miscellaneous uses (approximately 5 percent). Cities include Buffalo, Casper, Sheridan, and Gillette, WY. Land ownership is mostly private. Federal lands include the Thunder Basin National Grassland (U.S. Forest Service) and lands administered by the Bureau of Land Management. Areas of interest in MLRA 58B in Wyoming include Fort Phil Kearny State Historic Site, Glendo State Park, and Lake DeSmet. The elevations in MLRA 58B increase gradually from north to south and range from approximately 2,900 to 5,900 feet. A few buttes are higher than 6,800 feet. The average annual precipitation in this area ranges from 10 to 17 inches per year. Precipitation occurs mostly during the growing season, often during rapidly developing thunderstorms. Mean annual air temperature is 46 degrees Fahrenheit. Summer temperatures may exceed 100 degrees Fahrenheit. Winter temperatures may drop to below zero. Snowfall averages 45 inches per year, but varies from 25 to over 70 inches in some locales.
Classification relationships
USDA Natural Resources Conservation Service (NRCS):
Land Resource Region – G Western Great Plains Range and Irrigation; Major Land Resource Area (MLRA) – 58B Northern Rolling High Plains, Southern Part (USDA, 2006)
Relationship to Other Classifications:
USDA Forest Service (FS) Classification Hierarchy:
Province – 331 Great Plains-Palouse Dry Steppe; Section – 331G-Powder River Basin; Subsections – 331Gb Montana Shale Plains, 331Ge Powder River Basin, 331Gf South Powder River Basin-Scoria Hills (Cleland et al, 1997)
Environmental Protection Agency (EPA) Classification Hierarchy:
Level III Ecoregion – 43 Northwestern Great Plains; Level IV Ecoregion – 43p Scoria Hills, 43q Mesic-Dissected Plains, 43w Powder River Basin (EPA, 2013)
https://www.epa.gov/eco-research/ecoregions
Ecological site concept
This ecological site occurs on nearly level to gently sloping drainageways, floodplains, and stream terraces at elevations ranging from 2,900 to 5,900 feet. Slopes range from 0 to 6 percent. This site occurs on all aspects, although aspect is not a significant factor. The soils of this ecological site are deep to very deep and are well drained. The soil surface textures are typically fine sandy loam, sandy loam, or loam, but may include very fine sandy loam, silt loam, loamy fine sand, or clay loam.
Associated sites
R058BY104WY |
Clayey (Cy) 10-14” PZ The Clayey 10-14 ecological site occurs on slopes ranging from 0 to 15 percent and has soils with 35 percent or greater clay content. The Clayey 10-14 ecological site has lower total annual production and is positioned above the Lowland 10-14 ecological site. |
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R058BY122WY |
Loamy (Ly) 10-14” PZ The Loamy 10-14 ecological site occurs on slopes ranging from 0 to 15 percent. The Loamy 10-14 ecological site has lower total annual production and is positioned above the Lowland 10-14 ecological site. |
R058BY130WY |
Overflow (Ov) 10-14” PZ The Overflow 10-14 ecological site occurs on slopes ranging from 0 to 5 percent. The Overflow 10-14 ecological site is located on similar landform positions and has lower total annual production than the Lowland 10-14 ecological site. |
R058BY174WY |
Subirrigated (Sb) 10-17” PZ The Sub-Irrigated 10-17 ecological site occurs on slopes ranging from 0 to 6 percent. The Sub-Irrigated 10-17 ecological site is located on similar landform positions and has higher total annual production than the Lowland 10-14 ecological site. |
Similar sites
R058BY130WY |
Overflow (Ov) 10-14” PZ The Overflow 10-14 ecological site occurs on slopes ranging from 0 to 5 percent. The Overflow 10-14 ecological site is located on similar landform positions and has lower total annual production than the Lowland 10-14 ecological site. |
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R058BY138WY |
Saline Lowland (SL) 10-14” PZ Saline Lowland 10-14 ecological site occurs on slopes ranging from 0 to 6 percent. The Saline Lowland 10-14 ecological site is located on similar landform positions, has a greater composition of salt tolerant species, and has lower total annual production than the Lowland 10-14 ecological site. |
R058BY142WY |
Saline Subirrigated (SS) 10-14” PZ Saline Sub-Irrigated 10-14 ecological site occurs on slopes ranging from 0 to 6 percent. The Saline Sub-Irrigated 10-14 ecological site is located on similar landform positions, has a greater composition of salt tolerant species, and has higher total annual production than the Lowland 10-14 ecological site. |
R058BY174WY |
Subirrigated (Sb) 10-17” PZ The Sub-Irrigated 10-17 ecological site occurs on slopes ranging from 0 to 6 percent. The Sub-Irrigated 10-17 ecological site is located on similar landform positions and has higher total annual production than the Lowland 10-14 ecological site. |
Table 1. Dominant plant species
Tree |
(1) Populus deltoides |
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Shrub |
(1) Artemisia cana |
Herbaceous |
(1) Leymus cinereus |
Click on box and path labels to scroll to the respective text.
Ecosystem states
T1A | - | Prolonged drought, improper grazing, or a combination of these factors |
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R2A | - | Proper grazing management in combination with rangeland seeding, grazing land mechanical treatment, and timely moisture (management intensive and costly) |
T2A | - | Introduction of non-native, invasive species (annual bromes, crested wheatgrass, noxious weeds) |
State 1 submodel, plant communities
1.1A | - | Drought, improper grazing management |
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1.2A | - | Normal or above average precipitation; proper grazing management |