USA Soil Map: Interactive SSURGO Soil Explorer

Explore soil types across the United States with this interactive map, powered by the USDA NRCS SSURGO database — the most detailed national soil survey dataset available. Zoom in to any location to view official soil map unit boundaries, then click to instantly retrieve soil classification, drainage characteristics, farmland designation, and taxonomic classification for that spot.

 

How to Use This Map

Getting Started

The map opens at a national view of the continental United States. SSURGO soil data only renders at zoom level 12 and above — zoom into any area to see the orange polygon boundaries appear. A prompt in the centre of the map will guide you when more zoom is needed.

Reading Map Unit Symbols

Each polygon carries a map unit symbol such as 377C or 11B2. The format encodes key information at a glance:

• Number prefix (e.g. 377) — local soil series identifier used in the county soil survey
• Letter suffix (e.g. C) — slope phase: A = 0-2%, B = 2-6%, C = 6-12%, D = 12-18%, E = 18-25%, F = 25%+
• Trailing number (e.g. 2) — erosion phase: 1 = slightly eroded, 2 = moderately eroded, 3 = severely eroded

Click to Query Soil Data

At zoom level 12 or higher, click any point on the map to query the USDA Soil Data Access API. The bar below the map will display:

• Map Unit Name — the full soil series name and slope description
• Unit Type — whether the unit is a consociation, complex, or association
• Soil Taxonomy — USDA Order and Suborder classification
• Drainage Class — from excessively drained to very poorly drained
• Farmland Classification — prime farmland, unique farmland, or not prime

Other Controls

• Opacity slider — adjust the transparency of the soil overlay to see the basemap beneath
• Basemap buttons — switch between Streets, Topographic, and Satellite imagery
• ? Legend — opens a reference panel explaining symbols and field definitions
• Copy link — shares a URL that preserves your current location, zoom, and opacity

About SSURGO and the US Soil Survey

The Soil Survey Geographic Database (SSURGO) is the most detailed soil survey database produced by the USDA Natural Resources Conservation Service (NRCS). It was compiled from field surveys conducted at county and regional levels since the 1950s, with ongoing updates as new data becomes available.

SSURGO captures soil properties at scales of 1:12,000 to 1:63,360 — detailed enough to guide decisions at the individual field level. Each soil map unit delineated in the database represents a distinct combination of soil type, slope, and surface condition, mapped by trained soil scientists conducting on-the-ground surveys.

The database contains information on hundreds of soil properties including texture, pH, organic matter content, hydraulic conductivity, available water capacity, and depth to restrictive layers. These attributes underpin decisions in agriculture, land use planning, engineering, and environmental management across the United States.

US Soil Taxonomy Orders

USDA Soil Taxonomy classifies soils into 12 Orders at the broadest level. When you click the map, the taxonomy order shown in the results indicates the broad pedogenic environment of that soil:

• Mollisols — dark, organically rich soils of grasslands; some of the world’s most productive farmland, dominant across the Great Plains
• Alfisols — moderately leached forest soils with a subsurface clay-rich layer; common in the Midwest and Southeast
• Ultisols — strongly weathered, acidic soils of humid subtropical regions, widespread in the Southeast US
• Entisols — recently formed soils with little profile development; found on floodplains and sandy deposits
• Inceptisols — young soils showing early development; widespread in humid mountain and valley regions
• Spodosols — acidic, sandy soils with a distinctive bleached layer; common in northern forests and the Atlantic coastal plain
• Aridisols — dry desert soils with low organic matter; dominant across the Southwest and Great Basin
• Vertisols — clay-rich shrink-swell soils that crack when dry; found in Texas blackland prairies and the Mississippi Valley
• Histosols — organic peat and muck soils formed in wetlands; found in the Everglades, Pacific Northwest bogs, and northern peatlands

Frequently Asked Questions

Why does the soil data only appear when I zoom in?

SSURGO is a large-scale dataset mapped at county resolution, typically at 1:12,000 to 1:24,000 scale. The polygons are too small to render meaningfully at a national or regional view. The data becomes visible at zoom level 12 and above, equivalent to viewing an area roughly 10-20 km across.

What is the difference between a consociation, complex, and association?

A consociation is dominated by a single soil series (typically 50% or more of the area). A complex contains two or more soil types that are too intermingled to separate at the mapping scale. An association also contains two or more soils, but they could theoretically be mapped separately at a larger scale.

What does the Farmland Classification mean?

Prime farmland has the best combination of physical and chemical characteristics for producing food, feed, and fibre with minimum inputs. Farmland of statewide importance and farmland of local importance are secondary categories. Land classified as not prime includes steeply sloped, rocky, wet, or otherwise limited soils.

Can I download the soil data?

This map visualises the USDA NRCS SSURGO dataset. To download the full dataset with all 173 attribute fields, visit the USDA Web Soil Survey, which allows custom area-of-interest downloads in GIS formats. The Soil Data Access API used by this tool also supports direct SQL-style queries for programmatic access.

How current is the data?

SSURGO is continuously updated by NRCS staff. Individual survey areas may have been originally mapped decades ago, though many have been updated with modern field methods. The Web Soil Survey notes the survey date for each county area.

Data Sources and Limitations

Soil map unit polygons are served via the USDA NRCS Soil Data Mart WMS. Attribute data on click is queried from the Soil Data Access API. Both services are operated by the USDA Natural Resources Conservation Service. Coverage is limited to areas with completed soil surveys; some remote or tribal lands may have incomplete or no coverage. Attribute values represent dominant condition aggregations from the SSURGO muaggatt table.

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