Soil series profile

Begay soil series

Begay is a well drained soil with a very fine sandy loam surface, mapped on 556,750 acres in 19 counties across 5 states. Hydrologic group A.

#474 by mapped area coarse-loamy Ustic Haplocambids (Aridisols)

Drainage class: Well drained
Hydrologic group: A
Typical topsoil pH: 8.1
Mapped area: 557k

Typical Begay 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 Begay horizons (representative values)
Depth	Texture	pH	Clay	Sand	Organic matter
0–4 in (H1)	Very fine sandy loam	7.9	10%	64%	1.5%
4–57 in (H2)	Very fine sandy loam	7.9	10%	64%	0.75%
57–84 in (H3)	Loamy fine sand	7.9	8%	83%	0.25%

Representative values from the most extensive Begay map unit (Penistaja-Begay complex, 1 to 8 percent slopes, survey area AZ714). 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 Begay soil means for gardens, lawns and septic systems

For gardens

Typical topsoil in Begay soils is moderately alkaline: pH 8.1 (most land between 7.9 and 8.2). Acid-loving plants such as blueberries and azaleas struggle without amended beds, and some trees and shrubs show iron chlorosis (yellow leaves with green veins).

Loamy topsoil (loam, silt loam and similar) covers 63% of mapped Begay acres: generally the easiest soil to garden, holding moisture without staying waterlogged. The most common surface texture is fine sandy loam (46% of mapped Begay acres).

94% of mapped Begay acres is moderately well to excessively drained, which suits most garden plants.

For lawns and yards

71% 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 15% of the acres in mapped Begay soils very limited, 11% somewhat limited and 68% not limited (6% not rated, such as urban land, pits or water).

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 Begay soil is found

Mapped acres

Begay is mapped in Arizona, Utah, Colorado, Wyoming and New Mexico.

Counties with the most mapped Begay soil
County	Acres	Share of county land
Navajo County, AZ	147,295	2.6%
San Juan County, UT	101,248	2.1%
Apache County, AZ	100,317	1.5%
Wayne County, UT	67,615	4.6%
Grand County, UT	51,161	2.4%
Uintah County, UT	25,493	1.1%
Coconino County, AZ	16,817	0.1%
Garfield County, UT	15,734	0.8%
Mohave County, AZ	8,389	0.1%
Kane County, UT	8,169	0.3%
Hot Springs County, WY	2,036	0.2%
Park County, WY	1,569	0.1%
Garfield County, CO	1,350	0.1%
Mesa County, CO	1,251	0.1%
Rio Blanco County, CO	477	0.0%
Piute County, UT	448	0.2%
Moffat County, CO	422	0.0%
Sevier County, UT	311	0.1%
McKinley County, NM	148	0.0%

Septic absorption fields

NRCS rating, share of Begay acres

Not limited 68%

Somewhat limited 11%

Very limited 15%

Not rated 6%

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

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Septic tank absorption field rating across mapped Begay acres.
Category	Share of acres
Not limited	67.8%
Somewhat limited	11.3%
Very limited	14.7%
Not rated	6.2%

Drainage, water table and flooding

Share of Begay 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 3–15% (median 5%).
Topsoil organic matter: Median 1.5%.

Drainage class

Excessively drained 0%

Somewhat excessively drained 6%

Well drained 88%

Moderately well drained 0%

Somewhat poorly drained 0%

Poorly drained 0%

Very poorly drained 0%

Not rated 6%

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

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Drainage class across mapped Begay acres.
Category	Share of acres
Excessively drained	0.0%
Somewhat excessively drained	6.3%
Well drained	87.8%
Moderately well drained	0.0%
Somewhat poorly drained	0.0%
Poorly drained	0.0%
Very poorly drained	0.0%
Not rated	5.9%

Hydrologic soil group

A: fast infiltration (mostly sandy or gravelly) 71%

B: moderate infiltration 23%

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%

Not rated 6%

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

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Hydrologic soil group across mapped Begay acres.
Category	Share of acres
A: fast infiltration (mostly sandy or gravelly)	70.8%
B: moderate infiltration	23.0%
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%
Not rated	6.2%

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 Begay (component kind "Series") in SSURGO: 556,750 acres.
Method: Shares are by mapped acres of Begay components. The profile comes from the single largest Begay component. Full methodology.

Independent reference site. No government affiliation or endorsement.

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