Soil series profile

Olney soil series

Olney is a well drained soil with a fine sandy loam surface, mapped on 675,006 acres in 26 counties across 4 states. Hydrologic group B.

#361 by mapped area fine-loamy Ustic Haplargids (Aridisols)

Drainage class: Well drained
Hydrologic group: B
Typical topsoil pH: 7.2
Mapped area: 675k

Typical Olney 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 Olney horizons (representative values)
Depth	Texture	pH	Clay	Sand	Organic matter
0–6 in (H1)	Fine sandy loam	7.2	15%	65%	0.75%
6–18 in (H2)	Sandy clay loam	7.2	27%	56%	0.75%
18–60 in (H3)	Sandy loam	8.2	19%	63%	0.25%
60–64 in (H4)	Sandy loam	8.5	10%	64%	0.25%

Representative values from the most extensive Olney map unit (Olney fine sandy loam, 0 to 6 percent slopes, survey area CO617). 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 Olney soil means for gardens, lawns and septic systems

For gardens

Typical topsoil in Olney soils is neutral: pH 7.2 (most land between 6.8 and 7.2), the range most vegetables, flowers and lawn grasses prefer.

Loamy topsoil (loam, silt loam and similar) covers 87% of mapped Olney acres: generally the easiest soil to garden, holding moisture without staying waterlogged. The most common surface texture is sandy loam (50% of mapped Olney acres).

100% of mapped Olney acres is moderately well to excessively drained, which suits most garden plants.

For lawns and yards

Most land is in hydrologic groups B and C, where rain soaks in at a moderate pace.

For a septic system

For conventional septic absorption fields, NRCS rates 7% of the acres in mapped Olney soils very limited, 43% somewhat limited and 50% not limited.

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 Olney soil is found

Mapped acres

Olney is mapped in Colorado, Wyoming, Montana and Nebraska.

Counties with the most mapped Olney soil
County	Acres	Share of county land
Weld County, CO	248,617	9.7%
Pueblo County, CO	65,631	4.4%
El Paso County, CO	62,948	4.3%
Lincoln County, CO	57,457	3.5%
Crowley County, CO	53,014	10.4%
Kiowa County, CO	46,478	4.0%
Bent County, CO	42,172	4.3%
Otero County, CO	22,161	2.8%
Huerfano County, CO	13,123	1.3%
Las Animas County, CO	9,215	0.3%
Arapahoe County, CO	7,948	1.5%
Garfield County, CO	7,830	0.4%
Cheyenne County, CO	6,824	0.6%
Washakie County, WY	6,099	0.4%
Logan County, CO	5,231	0.4%
Park County, WY	3,797	0.2%
Hot Springs County, WY	3,272	0.3%
Sioux County, NE	2,940	0.2%
Carbon County, MT	2,819	0.2%
Baca County, CO	2,675	0.2%
Prowers County, CO	1,904	0.2%
Morgan County, CO	1,660	0.2%
Big Horn County, MT	704	0.0%
Big Horn County, WY	284	0.0%
Fremont County, CO	115	0.0%
Boulder County, CO	90	0.0%

Septic absorption fields

NRCS rating, share of Olney acres

Not limited 50%

Somewhat limited 43%

Very limited 7%

Not rated <1%

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

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Septic tank absorption field rating across mapped Olney acres.
Category	Share of acres
Not limited	49.8%
Somewhat limited	43.3%
Very limited	6.7%
Not rated	0.1%

Drainage, water table and flooding

Share of Olney acres

Depth to seasonal high water table: About 4.9 feet (59 in) (median where reported).
Flooding: Not mapped as flooding on most acres.
Slope: Typically 1–8% (median 2%).
Topsoil organic matter: Median 1.2%.

Drainage class

Excessively drained 0%

Somewhat excessively drained 0%

Well drained >99%

Moderately well drained <1%

Somewhat poorly drained 0%

Poorly drained 0%

Very poorly drained 0%

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

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Drainage class across mapped Olney acres.
Category	Share of acres
Excessively drained	0.0%
Somewhat excessively drained	0.0%
Well drained	99.9%
Moderately well drained	0.1%
Somewhat poorly drained	0.0%
Poorly drained	0.0%
Very poorly drained	0.0%

Hydrologic soil group

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

B: moderate infiltration 99%

C: slow infiltration 1%

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 <1%

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

Show as a table

Hydrologic soil group across mapped Olney acres.
Category	Share of acres
A: fast infiltration (mostly sandy or gravelly)	0.0%
B: moderate infiltration	98.9%
C: slow infiltration	1.0%
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	0.1%

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 Olney (component kind "Series") in SSURGO: 675,006 acres.
Method: Shares are by mapped acres of Olney components. The profile comes from the single largest Olney component. Full methodology.

Independent reference site. No government affiliation or endorsement.

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