USDA SSURGO COUNTY SOIL REFERENCE

Anchorage Municipality, Alaska Soil Summary

This page summarizes USDA SSURGO mapped soil information for Anchorage Municipality, Alaska.

Mapped Land Coverage
99.52%1,238,550.07 mapped acres of 1,244,480.67 Census land acres

Coverage measures mapped SSURGO intersection with Census land geometry. It does not mean that every parcel or point has complete soil information.

Soil at a Glance

Largest mapped soil unit
Cook Inlet Mountains-Boreal Alpine-Mountains
Symbol: E23M4 • 18.52% of mapped area
Largest estimated component
E23-boreal rock outcrop and rubbleland
340,855.95 acres (27.52% of mapped area)
Mapped units & components
146 mapped soil units
Top 15 shown below · 108 component series
Dominant drainage class
Unknown / Unmapped
Highest acreage drainage class
Dominant hydrologic group
Group Unknown / Unmapped
Runoff potential classification
Weighted average slope
37.6%
Terrain slope analysis
Looking at a specific U.S. address?

Check soil and other available public land data for a U.S. address

County summaries provide regional context across mapped soil units. Address lookup combines available public datasets for the Census-matched location.

Top Mapped Soil Units

Showing the 15 largest mapped units, representing 73.95% of mapped soil area.
SymbolMap Unit NameMapped Acres% of Mapped Area
E23M4Cook Inlet Mountains-Boreal Alpine-Mountains229,319.8118.52%
E23M7Cook Inlet Mountains-Boreal Alpine-Barren Mountains118,708.39.58%
464Water, saline93,518.217.55%
E23M4Cook Inlet Mountains-Boreal Alpine-Mountains75,193.876.07%
E28RCInterior Alaska Mountains-Boreal Alpine-Barren Mountains54,547.074.4%
E23M4Cook Inlet Mountains-Boreal Alpine-Mountains48,287.363.9%
E22M5Southern Alaska Coastal Mountains-Maritime Alpine-Barren Mountains46,208.233.73%
E23M7Cook Inlet Mountains-Boreal Alpine-Barren Mountains42,094.493.4%
E23M7Cook Inlet Mountains-Boreal Alpine-Barren Mountains37,331.183.01%
E23VCook Inlet Mountains-Boreal Upland and Lowland-Valleys32,548.422.63%
E23VCook Inlet Mountains-Boreal Upland and Lowland-Valleys31,112.582.51%
E23M7Cook Inlet Mountains-Boreal Alpine-Barren Mountains29,066.812.35%
E24WCook Inlet Lowlands-Boreal Water, Saline28,646.342.31%
439Nakochna-Rock outcrop association, 20 to 85 percent slopes26,464.312.14%
406Cryorthents and Urban land, 0 to 5 percent slopes22,852.291.85%
E23M418.52% of mapped area

Cook Inlet Mountains-Boreal Alpine-Mountains

Mapped Area229,319.81 acres
Rank#1 of 146 in county
E23M79.58% of mapped area

Cook Inlet Mountains-Boreal Alpine-Barren Mountains

Mapped Area118,708.3 acres
Rank#2 of 146 in county
4647.55% of mapped area

Water, saline

Mapped Area93,518.21 acres
Rank#3 of 146 in county
E23M46.07% of mapped area

Cook Inlet Mountains-Boreal Alpine-Mountains

Mapped Area75,193.87 acres
Rank#4 of 146 in county
E28RC4.4% of mapped area

Interior Alaska Mountains-Boreal Alpine-Barren Mountains

Mapped Area54,547.07 acres
Rank#5 of 146 in county
E23M43.9% of mapped area

Cook Inlet Mountains-Boreal Alpine-Mountains

Mapped Area48,287.36 acres
Rank#6 of 146 in county
E22M53.73% of mapped area

Southern Alaska Coastal Mountains-Maritime Alpine-Barren Mountains

Mapped Area46,208.23 acres
Rank#7 of 146 in county
E23M73.4% of mapped area

Cook Inlet Mountains-Boreal Alpine-Barren Mountains

Mapped Area42,094.49 acres
Rank#8 of 146 in county
E23M73.01% of mapped area

Cook Inlet Mountains-Boreal Alpine-Barren Mountains

Mapped Area37,331.18 acres
Rank#9 of 146 in county
E23V2.63% of mapped area

Cook Inlet Mountains-Boreal Upland and Lowland-Valleys

Mapped Area32,548.42 acres
Rank#10 of 146 in county
E23V2.51% of mapped area

Cook Inlet Mountains-Boreal Upland and Lowland-Valleys

Mapped Area31,112.58 acres
Rank#11 of 146 in county
E23M72.35% of mapped area

Cook Inlet Mountains-Boreal Alpine-Barren Mountains

Mapped Area29,066.81 acres
Rank#12 of 146 in county
E24W2.31% of mapped area

Cook Inlet Lowlands-Boreal Water, Saline

Mapped Area28,646.34 acres
Rank#13 of 146 in county
4392.14% of mapped area

Nakochna-Rock outcrop association, 20 to 85 percent slopes

Mapped Area26,464.31 acres
Rank#14 of 146 in county
4061.85% of mapped area

Cryorthents and Urban land, 0 to 5 percent slopes

Mapped Area22,852.29 acres
Rank#15 of 146 in county

Estimated Soil Components

Showing the 15 largest estimated component series. Component acreages are estimated from SSURGO map-unit component percentages (comppct_r) applied to spatially measured map-unit acreage.
ComponentDrainage ClassHydrologic GroupEstimated Acres% of Mapped Area
E23-boreal rock outcrop and rubblelandUnspecifiedUnspecified340,855.9527.52%
WaterUnspecifiedUnspecified93,761.337.57%
E23-boreal alpine scrub-gravelly colluvial slopesWell drainedA92,334.567.46%
E23-boreal subalpine scrub/meadow mosaic-silty till slopesWell drainedA72,065.745.82%
E28-boreal alpine rock outcrop and rubblelandUnspecifiedUnspecified52,365.194.23%
E23-boreal alpine scrub-silty hummocksWell drainedB48,013.973.88%
E22-maritime glaciers and permanent snowfieldsUnspecifiedUnspecified36,310.362.93%
E24-boreal water, salineUnspecifiedUnspecified34,372.72.78%
E23-boreal alpine dwarf scrub-gravelly colluvial slopesWell drainedB34,091.072.75%
E23-boreal forest-silty till slopesWell drainedB30,946.482.5%
E23-boreal permanent snow and iceUnspecifiedUnspecified29,536.12.38%
DeceptionWell drainedB24,067.671.94%
KichatnaWell drainedB19,446.141.57%
TalkeetnaWell drainedB19,302.91.56%
CryorthentsSomewhat excessively drained, Well drainedB18,525.251.5%
Component acreage is estimated from SSURGO map-unit component percentages. Component values are not independently mapped polygon boundaries.

E23-boreal rock outcrop and rubbleland

27.52%
Estimated Acres340,855.95
Drainage ClassUnspecified
Hydrologic GroupUnspecified

Water

7.57%
Estimated Acres93,761.33
Drainage ClassUnspecified
Hydrologic GroupUnspecified

E23-boreal alpine scrub-gravelly colluvial slopes

7.46%
Estimated Acres92,334.56
Drainage ClassWell drained
Hydrologic GroupA

E23-boreal subalpine scrub/meadow mosaic-silty till slopes

5.82%
Estimated Acres72,065.74
Drainage ClassWell drained
Hydrologic GroupA

E28-boreal alpine rock outcrop and rubbleland

4.23%
Estimated Acres52,365.19
Drainage ClassUnspecified
Hydrologic GroupUnspecified

E23-boreal alpine scrub-silty hummocks

3.88%
Estimated Acres48,013.97
Drainage ClassWell drained
Hydrologic GroupB

E22-maritime glaciers and permanent snowfields

2.93%
Estimated Acres36,310.36
Drainage ClassUnspecified
Hydrologic GroupUnspecified

E24-boreal water, saline

2.78%
Estimated Acres34,372.7
Drainage ClassUnspecified
Hydrologic GroupUnspecified

E23-boreal alpine dwarf scrub-gravelly colluvial slopes

2.75%
Estimated Acres34,091.07
Drainage ClassWell drained
Hydrologic GroupB

E23-boreal forest-silty till slopes

2.5%
Estimated Acres30,946.48
Drainage ClassWell drained
Hydrologic GroupB

E23-boreal permanent snow and ice

2.38%
Estimated Acres29,536.1
Drainage ClassUnspecified
Hydrologic GroupUnspecified

Deception

1.94%
Estimated Acres24,067.67
Drainage ClassWell drained
Hydrologic GroupB

Kichatna

1.57%
Estimated Acres19,446.14
Drainage ClassWell drained
Hydrologic GroupB

Talkeetna

1.56%
Estimated Acres19,302.9
Drainage ClassWell drained
Hydrologic GroupB

Cryorthents

1.5%
Estimated Acres18,525.25
Drainage ClassSomewhat excessively drained, Well drained
Hydrologic GroupB
Component acreage is estimated from SSURGO map-unit component percentages. Component values are not independently mapped polygon boundaries.

Drainage Class Distribution

Unknown / Unmapped51.88%
642,544 acres
Well drained36.56%
452,820.14 acres
Very poorly drained5.3%
65,645.14 acres
Poorly drained2.92%
36,182.84 acres
Somewhat excessively drained1.71%
21,236.99 acres
Somewhat poorly drained0.94%
11,694.36 acres
Moderately well drained0.5%
6,209.34 acres
Excessively drained0.18%
2,217.31 acres

Hydrologic Soil Group Distribution

Group Unknown / Unmapped51.92%
643,049.71 acres
Group B22.14%
274,269.5 acres
Group A14.52%
179,785.67 acres
Group D6.01%
74,459.53 acres
Group A/D2.75%
34,026.47 acres
Group C1.41%
17,412.57 acres
Group B/D1.2%
14,910.88 acres
Group C/D0.05%
635.79 acres

Hydrologic soil groups are USDA/NRCS classifications related to runoff potential under specified soil conditions. They are not a property-level flood-risk rating.

Slope Characteristics

Weighted Average Slope: 37.6%
Nearly Level (0-2%)17.29%
214,143.3 acres
Gently Sloping (2-8%)4.21%
52,194.55 acres
Moderately Sloping (8-15%)6.42%
79,569.8 acres
Steep (15-30%)14.57%
180,504.93 acres
Very Steep (>30%)57.46%
711,646.47 acres
Unspecified Slope0.04%
491.07 acres

Sources & Methodology

USDA NRCS SSURGO

Mapped soil units, components, drainage classes, hydrologic groups, and slope ratings derived from official Soil Data Access REST services.

U.S. Census Bureau TIGER/Line

County land geometry used for county-level coverage calculation.

Coverage Method

Mapped acreage is calculated from true spatial vector intersection of county land geometry and SSURGO mapped soil polygons using NAD83 / CONUS Albers Equal Area projection (EPSG:5070).