Soil series profile

Shanahan soil series

Shanahan is a somewhat excessively drained soil with a ashy loamy coarse sand surface, mapped on 149,752 acres in 3 counties in OR. Hydrologic group A.

#2468 by mapped area ashy over loamy Xeric Vitricryands (Andisols)

Drainage class: Somewhat excessively drained
Hydrologic group: A
Typical topsoil pH: 6.3
Mapped area: 150k

Typical Shanahan 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).

Show as a table

Typical Shanahan horizons (representative values)
Depth	Texture	pH	Clay	Sand	Organic matter
0–6 in (A)	Ashy loamy coarse sand	6.3	3%	78%	3%
6–13 in (Bw1)	Ashy loamy coarse sand	6.4	2%	80%	1.5%
13–20 in (Bw2)	Paragravelly ashy loamy coarse sand	6.5	2%	81%	0.5%
20–28 in (C1)	Paragravelly ashy coarse sand	6.5	1%	92%	0.2%
28–34 in (C2)	Ashy coarse sand	6.6	1%	93%	0.15%
34–49 in (2Ab)	Sandy loam	6.6	4%	65%	0.35%
49–60 in (2Bwb)	Sandy loam	6.9	5%	68%	0.18%

Representative values from the most extensive Shanahan map unit (Shanahan ashy loamy coarse sand, 0 to 15 percent slopes, survey area OR605). 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 Shanahan soil means for gardens, lawns and septic systems

For gardens

Typical topsoil in Shanahan soils is slightly acidic: pH 6.3 (most land between 6.3 and 6.7), the range most vegetables, flowers and lawn grasses prefer.

Sandy topsoil covers 100% of mapped Shanahan acres. It drains fast and warms early in spring, but dries out and loses nutrients quickly: mulch, compost and steady watering help. The most common surface texture is loamy coarse sand (35% of mapped Shanahan acres).

100% of mapped Shanahan acres is excessively or somewhat excessively drained: water moves through fast, so gardens need more frequent watering in dry spells.

For lawns and yards

93% of mapped acres is in hydrologic group A, where water soaks in fast. Lawns there dry out quickly; deeper, less frequent watering and organic matter help.

For a septic system

For conventional septic absorption fields, NRCS rates 100% of the acres in mapped Shanahan soils very limited, 0% somewhat limited and 0% not limited.

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 Shanahan soil is found

Mapped acres

Shanahan is mapped in Oregon.

Counties with the most mapped Shanahan soil
County	Acres	Share of county land
Deschutes County, OR	114,643	5.9%
Klamath County, OR	20,622	0.7%
Lake County, OR	14,311	0.3%

Septic absorption fields

NRCS rating, share of Shanahan acres

Not limited 0%

Somewhat limited 0%

Very limited 100%

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

Show as a table

Septic tank absorption field rating across mapped Shanahan acres.
Category	Share of acres
Not limited	0.0%
Somewhat limited	0.0%
Very limited	100.0%

Drainage, water table and flooding

Share of Shanahan acres

Depth to seasonal high water table: None reported within about 6.5 feet (median where reported).
Flooding: Not mapped as flooding on most acres.
Slope: Typically 2–8% (median 7%).
Topsoil organic matter: Median 3%.

Drainage class

Excessively drained 0%

Somewhat excessively drained 100%

Well drained 0%

Moderately well drained 0%

Somewhat poorly drained 0%

Poorly drained 0%

Very poorly drained 0%

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

Show as a table

Drainage class across mapped Shanahan acres.
Category	Share of acres
Excessively drained	0.0%
Somewhat excessively drained	100.0%
Well drained	0.0%
Moderately well drained	0.0%
Somewhat poorly drained	0.0%
Poorly drained	0.0%
Very poorly drained	0.0%

Hydrologic soil group

A: fast infiltration (mostly sandy or gravelly) 93%

B: moderate infiltration 7%

C: slow infiltration 0%

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%

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

Show as a table

Hydrologic soil group across mapped Shanahan acres.
Category	Share of acres
A: fast infiltration (mostly sandy or gravelly)	92.7%
B: moderate infiltration	7.3%
C: slow infiltration	0.0%
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%

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 Shanahan (component kind "Series") in SSURGO: 149,752 acres.
Method: Shares are by mapped acres of Shanahan components. The profile comes from the single largest Shanahan component. Full methodology.

Independent reference site. No government affiliation or endorsement.

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