Natural Resources
Conservation Service
Major Land Resource Area 102B
Major Land Resource Area
Accessed: 04/16/2026
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1
Select an ecological site
Select an ecological site using the list, keys, photos, briefcase, or quick search option located on this page. -
2
Explore the ecological site description
Next, learn more about the selected ecological site and its characteristic dynamics by browsing the ecological site description and exploring alternative state and transition model formats.
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Zoom in to display soil survey map units for an area of interest, and zoom out to display MLRAs. Select a map unit polygon to view ecological sites correlated to that map unit. View a brief description of an ecological site by clicking on its name in the map popup. Soil survey correlations may not be accurate, and ecological site classification of a location should always be verified in the field. Each selection may require the transfer of several hundred KB of data.
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Add ecological sites and Major Land Resource Areas to your briefcase by clicking on the briefcase (
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Ecological sites
Major Land Resource Areas
Ecological site photos
Tools
Filter by
interactive key
precipitation
frost free days
more..
clear all
Type
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Filters
Interactive key
Precipitation
Frost free days
Elevation
Slope
Landform
Parent material kind
Soil texture
RUN-OFF LANDSCAPE POSITIONS
Normal Landscape Positions
RUN-IN LANDSCAPE POSITIONS
(Floodplain, Drainageways, etc., except depressions)
Observe the soil profile to a depth to 60 inches.
OTHER LANDSCAPE POSITIONS
(Basin, Depression, Run-off and/or Run-in)
Does the soil have a claypan (columnar structure) within 16 inches?
Dig hole to a depth of 20 inches
Is there a root restricting layer within 10 inches of soil surface?
Very Shallow
R102BY016SD – Very Shallow
R102BY016SD – Very Shallow
Is there a root restricting layer within 10-20 inches of soil surface?
Does the soil effervesce with acid (10% HCL) at or near (within 6 inches) the surface?
Gravel ?
(greater than 15%
by volume)
Thin Upland
R102BY012SD – Thin Upland
R102BY012SD – Thin Upland
See “Normal Landscape Positions”
Shallow To Gravel
R102BY014SD – Shallow To Gravel
R102BY014SD – Shallow To Gravel
Dig hole to a depth of 20 inches
Are there visible salts (including sodium & gypsum) within 16 inches or a claypan of the surface?
Is there a claypan (columnar structure) within 16 inches of the surface?
See "OTHER LANDSCAPE POSITIONS".
What is the surface and subsoil texture?
Clay, Silty Clay (>40% clay) or Loamy Surface with Clayey Subsoil?
Loam, Silt Loam, Silty
Clay Loam, Clay Loam, Sandy Clay Loam, Very Fine Sandy Loam
Sandy Loam, Fine Sandy Loam, Loamy Very Fine Sand.
Sand, Loamy Sand, Loamy Fine Sand.
[Criteria]
R102BY011SD – Clayey
R102BY011SD – Clayey
R102BY010SD – Loamy
[Criteria]
R102BY009SD – Sandy
R102BY009SD – Sandy
[Criteria]
R102BY008SD – Sands
R102BY008SD – Sands
Is there evidence of a permanent1 water table within 0-2 feet of the surface and the site dominated by hydrophytes?
Are there visible salts (including sodium & gypsum) within 16 inches of the surface?
Is there evidence of a permanent water table within 2 to 5 feet of the surface?
Saline lowland
R102BY007SD – Saline Lowland
R102BY007SD – Saline Lowland
[Criteria]
R102BY002SD – Linear Meadow
R102BY002SD – Linear Meadow
Does the soil effervesce with acid (10% HCL) at or near (within 6 inches) the surface?
Does water flow into and over/through the site?
Subirrigated
R102BY003SD – Subirrigated
R102BY003SD – Subirrigated
Are there visible salts (including sodium & gypsum) within 16 inches of the surface?
Saline Subirrigated
–
–
Limy Subirrigated
R102BY006SD – Limy Subirrigated
R102BY006SD – Limy Subirrigated
See “Other Landscape Positions”
Does it have a flooding frequency?
Loam, Silt Loam, Silty Clay Loam, Clay Loam, Sandy Clay Loam
R102BY040SD – Loamy Floodplain
R102BY040SD – Loamy Floodplain
Loam, Silt Loam, Silty Clay Loam, Clay Loam, Sandy Clay Loam, Very Fine Sandy Loam
R102BY020SD – Loamy Overflow
R102BY020SD – Loamy Overflow
Is it in a closed depression?
Is the area in a basin or closed depression with no outlet?
Closed Depression
R102BY019SD – Closed Depression
R102BY019SD – Closed Depression
Re-think your position and start again!
Does the site pond water for 4 to 8 weeks in the spring or after heavy rain and have high organic matter content?
Wet Meadow
R102BY004SD – Wet Meadow
R102BY004SD – Wet Meadow
Does the site pond water greater than 8 weeks or until early summer and have high organic matter content?
Shallow Marsh
R102BY001SD – Shallow Marsh
R102BY001SD – Shallow Marsh
Does the site pond water year round in most years and have high organic matter content?
Deep Marsh
R102BY037SD – Deep Marsh
R102BY037SD – Deep Marsh
All other closed depressions or basins that pond water briefly after snowmelt or heavy rain or during abnormally wet years.
R102BY019SD – Closed Depression
R102BY019SD – Closed Depression
Long term average mean annual precipitation
- No filter
- 60 – 80cm (24 – 31in)
—
cm
Long term average frost free days
- No filter
- 110 – 130days
—
days
- No filter
- 200 – 400m (700 – 1300ft)
- 400 – 600m (1300 – 2000ft)
—
m
- No filter
- 0 – 3%
- 3 – 5%
- 5 – 10%
- 10 – 15%
- 15 – 20%
- 20 – 25%
- 25 – 30%
- 30 – 35%
—
%
- No filter
- Depression
- Drainageway
- Flood plain
- Hill
- Knoll
- Moraine
- Outwash plain
- Outwash terrace
- Plain
- Pothole
- Rim
- Swale
- Terrace
- Till plain
- No filter
- Alluvium
Soil surface texture
- No filter
- Clay loam
- Fine sandy loam
- Loam
- Loamy fine sand
- Silty clay
- Silty clay loam
- Silt loam
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Ecological site keys
MLRA 102B Ecological Site Key
l.
RUN-OFF LANDSCAPE POSITIONS
A.
Dig hole to a depth of 20 inches
Is there a root restricting layer within 10 inches of soil surface?
No
Is there a root restricting layer within 10-20 inches of soil surface?
No
Does the soil effervesce with acid (10% HCL) at or near (within 6 inches) the surface?
No
See “Normal Landscape Positions”
yes
Gravel ?
(greater than 15%
by volume)
II.
Normal Landscape Positions
A.
Dig hole to a depth of 20 inches
Are there visible salts (including sodium & gypsum) within 16 inches or a claypan of the surface?
Yes
Is there a claypan (columnar structure) within 16 inches of the surface?
See "OTHER LANDSCAPE POSITIONS".
No
What is the surface and subsoil texture?
i.
Clay, Silty Clay (>40% clay) or Loamy Surface with Clayey Subsoil?
ii.
Loam, Silt Loam, Silty
Clay Loam, Clay Loam, Sandy Clay Loam, Very Fine Sandy Loam
iii.
Sandy Loam, Fine Sandy Loam, Loamy Very Fine Sand.
iv.
Sand, Loamy Sand, Loamy Fine Sand.
III.
RUN-IN LANDSCAPE POSITIONS
(Floodplain, Drainageways, etc., except depressions)
Observe the soil profile to a depth to 60 inches.
A.
Is there evidence of a permanent1 water table within 0-2 feet of the surface and the site dominated by hydrophytes?
Yes
Are there visible salts (including sodium & gypsum) within 16 inches of the surface?
No
Is there evidence of a permanent water table within 2 to 5 feet of the surface?
Yes
Does the soil effervesce with acid (10% HCL) at or near (within 6 inches) the surface?
Yes
Are there visible salts (including sodium & gypsum) within 16 inches of the surface?
NO
Does water flow into and over/through the site?
NO
See “Other Landscape Positions”
Yes
Does it have a flooding frequency?
NO
Loam, Silt Loam, Silty Clay Loam, Clay Loam, Sandy Clay Loam, Very Fine Sandy Loam
... R102BY020SD – Loamy Overflow
IV.
OTHER LANDSCAPE POSITIONS
(Basin, Depression, Run-off and/or Run-in)
Does the soil have a claypan (columnar structure) within 16 inches?
Yes
Is it in a closed depression?
NO
Is the area in a basin or closed depression with no outlet?
No
Re-think your position and start again!
Yes
Does the site pond water for 4 to 8 weeks in the spring or after heavy rain and have high organic matter content?
NO
Does the site pond water greater than 8 weeks or until early summer and have high organic matter content?
NO
Does the site pond water year round in most years and have high organic matter content?
No
All other closed depressions or basins that pond water briefly after snowmelt or heavy rain or during abnormally wet years.
... R102BY019SD – Closed Depression
The Ecosystem Dynamics Interpretive Tool is an information system framework developed by the USDA-ARS Jornada Experimental Range, USDA Natural Resources Conservation Service, and New Mexico State University.
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