Soil survey area

Montgomery County, Missouri

Survey Area MO139• Missouri
The short version

The most common soil here is Mexico, on about 24% of the land: a silt loam, smooth, like flour. Keswick and Armster come next.

About 24% of the land drains well, and 54% stays wet for long stretches; groundwater comes within two feet of the surface under 47% of it.

USDA rates 99% of the land very limited for a standard septic drain field, and 93% very limited for homes with basements. That means extra cost or special design, not that it can't be done.

Worth knowing: 15% of the land floods occasionally or more, and bedrock lies within 40 inches under 11% of it.

Soils change over short distances, so look up an address below for the soil at that exact spot and the reasons behind each rating.

The ground underfoot

The soils you're most likely standing on

The biggest named soils in Montgomery County, Missouri, each drawn five feet deep from its official USDA description, in its recorded colors.

Mexico
24% of the area
Silt loam topsoil · poorly drained
Smooth, like flour. Fertile and holds water well.
Alfisols
Keswick
10% of the area
Loam topsoil · somewhat poorly drained
A balanced mix that crumbles in your hand. The gardener's ideal.
Alfisols
Armster
9% of the area
Loam topsoil · moderately well drained
A balanced mix that crumbles in your hand. The gardener's ideal.
Alfisols
Belknap
4% of the area
Silt loam topsoil · somewhat poorly drained
Smooth, like flour. Fertile and holds water well.
Inceptisols
Gasconade
4% of the area
Flaggy clay loam topsoil · somewhat excessively drained
Firm and a little sticky. Holds water and nutrients well.
Mollisols
Putnam
4% of the area
Silt loam topsoil · poorly drained
Smooth, like flour. Fertile and holds water well.
Alfisols

Dots mark gravel; white flecks mark lime. Shares are by acres across the survey area, and each mapped patch usually mixes several of these soils.

The biggest mapped areas

The dominant drainage class is Poorly drained and the dominant hydrologic group is D (very slow infiltration, high runoff). The most common soil order is Alfisols — moderately leached forest soils with a clay-enriched subsoil. This report summarizes the major soil map units across the survey area to help you understand what to expect when buying, building, or gardening in Montgomery County, Missouri. Search your address to find the exact soil composition, drainage, and series details at your specific location.

Soil Map UnitAcresDrainageHydro GroupDwellingsSeptic
Mexico silt loam, 1 to 4 percent slopes, eroded 73K Poorly drainedDVery limitedVery limited
Armster silt loam, 2 to 7 percent slopes 35K Moderately well drainedDVery limitedVery limited
Keswick silt loam, 5 to 9 percent slopes, eroded 23K Somewhat poorly drainedDVery limitedVery limited
Mexico silt loam, 0 to 2 percent slopes 20K Poorly drainedDVery limitedVery limited
Gasconade-Rock outcrop complex, 14 to 50 percent slopes, rubbly 17K Somewhat excessively drainedDVery limitedVery limited
Keswick silt loam, 9 to 14 percent slopes, eroded 12K Somewhat poorly drainedC/DVery limitedVery limited
Chilhowie, Gasconade, and Crider soils, 14 to 35 percent slopes 11K Well drainedDVery limitedVery limited
Lindley loam, 14 to 40 percent slopes 11K Well drainedCVery limitedVery limited
Goss very gravelly silt loam, 14 to 45 percent slopes 9K Well drainedCVery limitedVery limited
Hatton silt loam, 3 to 9 percent slopes 9K Moderately well drainedDVery limitedVery limited
Putnam silt loam, 0 to 1 percent slopes 8K Poorly drainedDVery limitedVery limited
Belknap silt loam, 1 to 3 percent slopes, frequently flooded 8K Somewhat poorly drainedB/DVery limitedVery limited
Belknap silt loam, 0 to 2 percent slopes, frequently flooded 7K Somewhat poorly drainedB/DVery limitedVery limited
Nodaway silt loam, 0 to 2 percent slopes, frequently flooded 7K Moderately well drainedBVery limitedVery limited
Holstein-Rock outcrop complex, 14 to 35 percent slopes 7K Well drainedCVery limitedVery limited
Armster clay loam, 5 to 9 percent slopes, severely eroded 4K Moderately well drainedDVery limitedVery limited
Twomile silt loam, 0 to 2 percent slopes, rarely flooded 4K Poorly drainedDVery limitedVery limited
Cedargap gravelly silt loam, 1 to 3 percent slopes, frequently flooded, cool 4K Well drainedBVery limitedVery limited
Winfield silt loam, 20 to 30 percent slopes, eroded 4K Moderately well drainedCVery limitedVery limited
Moniteau silt loam, 0 to 2 percent slopes, occasionally flooded 4K Poorly drainedC/DVery limitedVery limited

Soil Orders in This Area

The USDA classifies every soil into one of 12 soil orders. Here are the dominant orders found in this survey area.

Alfisols
Moderately weathered forest soils with clay-enriched subsoil. Productive for agriculture, generally good for building and septic.
Mollisols
Fertile grassland soils with thick, dark topsoil. Among the best for agriculture, building, and gardening.
Inceptisols
Young but developing soils found in mountains and river terraces. Variable properties — check drainage and bedrock depth.
Entisols
Young soils with little development — found on floodplains, dunes, and steep slopes. Properties vary widely by setting.

What This Means

Building & Foundations

About 93% of soils are rated "very limited" for dwellings with basements. Specific challenges include shallow bedrock, steep slopes, poor drainage in some areas, flood-prone areas. A geotechnical assessment is recommended before building.

Septic Systems

About 99% of soils are rated "very limited" for septic absorption fields. Poorly drained soils can't absorb septic effluent effectively. Engineered or alternative systems are frequently required. Always get a professional perc test before purchasing land that needs septic.

Gardening & Agriculture

Many soils hold water for extended periods. Raised beds are highly recommended to improve drainage for vegetables. Well-adapted native plants and water-loving species will do best in natural conditions.

Look Up a Specific Address

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