Soil series profile

Gilpin soil series

Gilpin is a well drained soil with a silt loam surface, mapped on 5,833,859 acres in 229 counties across 9 states. Hydrologic group C.

#2 by mapped area fine-loamy Typic Hapludults (Ultisols)

Drainage class: Well drained
Hydrologic group: C
Typical topsoil pH: 4.7
Mapped area: 5.8M

Typical Gilpin profile

Texture and pH by depth

Depth to scale. More strongly shaded layers hold more clay. Horizon names are the soil survey's (A = topsoil, B = subsoil, C = parent material).

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Typical Gilpin horizons (representative values)
Depth	Texture	pH	Clay	Sand	Organic matter
0–2 in (Oi)	Slightly decomposed plant material	4.0	Not reported	Not reported	85%
2–6 in (A)	Silt loam	4.6	21%	25%	2.25%
6–28 in (BA + Bt)	Channery silty clay loam	4.6	35%	10%	0.4%
28–34 in (C)	Very channery silty clay loam	4.6	35%	10%	0.2%
34–38 in (R)	Unweathered bedrock	Not reported	Not reported	Not reported	Not reported

Representative values from the most extensive Gilpin map unit (Gilpin-Peabody complex, 35 to 70 percent slopes, severely eroded, survey area WV624). Other map units of this series vary within the series range.

Stock photo for illustration, not a sample of this soil series. Credit on the Sources & method page.

What this means

What Gilpin soil means for gardens, lawns and septic systems

For gardens

Typical topsoil in Gilpin soils is very strongly acidic: pH 4.7 (most land between 4.5 and 5.3). Most vegetables and lawn grasses do best around 6.0 to 7.0, so lime is often needed; blueberries, azaleas and rhododendrons like it as it is.

Loamy topsoil (loam, silt loam and similar) covers 98% of mapped Gilpin acres: generally the easiest soil to garden, holding moisture without staying waterlogged. The most common surface texture is silt loam (62% of mapped Gilpin acres).

>99% of mapped Gilpin acres is moderately well to excessively drained, which suits most garden plants.

For lawns and yards

On 98% of mapped acres, rain soaks in slowly (hydrologic groups C and D, including dual groups that are D until drained). Expect runoff and puddles after heavy rain: core-aerate compacted lawns and keep ground sloping away from foundations.

For a septic system

For conventional septic absorption fields, NRCS rates 98% of the acres in mapped Gilpin soils very limited, <1% somewhat limited and 0% not limited (2% not rated, such as urban land, pits or water).

Where the soil is very limited (slow permeability, a high water table, flooding, shallow bedrock or steep slopes), alternative systems such as mound or sand-filter designs are common and cost more.

Only a licensed site evaluation or perc test at the actual lot decides whether a system is allowed and which design.

Generated from the mapped numbers above using fixed rules, not a site visit. See how these notes are written.

Where Gilpin soil is found

Mapped acres

Gilpin is mapped in West Virginia, Pennsylvania, Kentucky, Ohio, Tennessee, Indiana, Virginia, Maryland and New York. The 60 counties with the most Gilpin acres:

Counties with the most mapped Gilpin soil
County	Acres	Share of county land
Indiana County, PA	156,122	29.5%
Westmoreland County, PA	144,822	22.1%
Braxton County, WV	135,020	52.9%
Armstrong County, PA	124,942	30.0%
Kanawha County, WV	122,318	26.5%
Preston County, WV	119,331	35.2%
Roane County, WV	117,888	46.1%
Jefferson County, PA	113,994	27.3%
Monroe County, OH	112,346	38.5%
Morgan County, TN	107,493	32.3%
Scott County, TN	102,583	30.2%
Gilmer County, WV	102,580	56.0%
Ritchie County, WV	96,466	42.8%
Wetzel County, WV	94,436	52.5%
Lewis County, WV	93,075	45.6%
Dubois County, IN	91,284	33.3%
Doddridge County, WV	91,280	54.6%
Butler County, PA	87,280	17.4%
Clearfield County, PA	87,097	12.0%
Barbour County, WV	86,266	48.7%
Cabell County, WV	80,263	52.7%
Mason County, WV	79,501	36.0%
Garrett County, MD	78,818	17.5%
Putnam County, WV	77,954	45.6%
Allegheny County, PA	76,989	16.5%
Meigs County, OH	72,205	26.3%
Somerset County, PA	70,775	10.5%
Jackson County, WV	69,336	29.3%
Washington County, OH	68,856	17.0%
Tyler County, WV	67,166	51.9%
Clay County, WV	67,108	38.1%
Beaver County, PA	66,017	23.9%
Upshur County, WV	65,306	37.5%
Calhoun County, WV	64,940	44.2%
Harrison County, WV	64,826	29.4%
Gallia County, OH	64,638	21.5%
Fayette County, PA	60,573	12.0%
Bledsoe County, TN	60,487	23.2%
Jackson County, KY	59,570	26.9%
Cambria County, PA	58,571	13.4%
Cumberland County, TN	53,790	12.4%
Wayne County, WV	52,579	21.3%
Clay County, KY	50,248	16.7%
Lincoln County, WV	49,574	21.8%
Breckinridge County, KY	46,447	12.8%
Morgan County, OH	46,355	17.4%
Morgan County, KY	46,187	18.9%
Mercer County, WV	45,435	20.9%
Wood County, WV	45,057	21.9%
Clarion County, PA	44,303	11.5%
Breathitt County, KY	40,687	12.9%
Lawrence County, OH	40,292	13.9%
Noble County, OH	39,402	15.4%
Warren County, PA	39,181	6.9%
Vinton County, OH	38,292	14.4%
Wirt County, WV	37,904	30.0%
Jefferson County, OH	37,148	14.3%
Nicholas County, WV	36,909	11.6%
Wolfe County, KY	35,987	25.3%
Lee County, KY	33,741	25.3%

Septic absorption fields

NRCS rating, share of Gilpin acres

Not limited 0%

Somewhat limited <1%

Very limited 98%

Not rated 2%

Septic tank absorption field rating across mapped Gilpin acres. Scale 0 to 100% of mapped land.

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Septic tank absorption field rating across mapped Gilpin acres.
Category	Share of acres
Not limited	0.0%
Somewhat limited	0.2%
Very limited	98.1%
Not rated	1.7%

Drainage, water table and flooding

Share of Gilpin acres

Depth to seasonal high water table: About 1.5 feet (18 in) (median where reported).
Flooding: Not mapped as flooding on most acres.
Slope: Typically 12–53% (median 30%).
Topsoil organic matter: Median 3%.

Drainage class

Excessively drained 0%

Somewhat excessively drained <1%

Well drained >99%

Moderately well drained 0%

Somewhat poorly drained 0%

Poorly drained 0%

Very poorly drained 0%

Not rated <1%

Drainage class across mapped Gilpin acres. Scale 0 to 100% of mapped land.

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Drainage class across mapped Gilpin acres.
Category	Share of acres
Excessively drained	0.0%
Somewhat excessively drained	0.1%
Well drained	99.3%
Moderately well drained	0.0%
Somewhat poorly drained	0.0%
Poorly drained	0.0%
Very poorly drained	0.0%
Not rated	0.6%

Hydrologic soil group

A: fast infiltration (mostly sandy or gravelly) 0%

B: moderate infiltration <1%

C: slow infiltration 98%

D: very slow infiltration (clayey, shallow or wet) 0%

A/D: D as is, A if drained 0%

B/D: D as is, B if drained 0%

C/D: D as is, C if drained 0%

Not rated 2%

Hydrologic soil group across mapped Gilpin acres. Scale 0 to 100% of mapped land.

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Hydrologic soil group across mapped Gilpin acres.
Category	Share of acres
A: fast infiltration (mostly sandy or gravelly)	0.0%
B: moderate infiltration	0.3%
C: slow infiltration	98.0%
D: very slow infiltration (clayey, shallow or wet)	0.0%
A/D: D as is, A if drained	0.0%
B/D: D as is, B if drained	0.0%
C/D: D as is, C if drained	0.0%
Not rated	1.7%

Sources & data dates

Source: USDA NRCS Soil Survey Geographic Database (SSURGO), queried through Soil Data Access. Public domain.
Data date: SSURGO as published on November 3, 2026 (most recent survey area update October 26, 2026). NRCS refreshes SSURGO each October.
Scope: All map unit components named Gilpin (component kind "Series") in SSURGO: 5,833,859 acres.
Method: Shares are by mapped acres of Gilpin components. The profile comes from the single largest Gilpin component. Full methodology.

Independent reference site. No government affiliation or endorsement.

Full narrative description: USDA Official Soil Series Description for Gilpin.