📍
State soils

Northern Mariana Islands Soil Surveys

2 survey areas
The short version

The most common soil here is Chinen, on about 19% of the land. Luta and Takpochao come next.

About 93% of the land drains well.

USDA rates 97% of the land very limited for a standard septic drain field, and 90% very limited for homes with basements. That means extra cost or special design, not that it can't be done.

Worth knowing: bedrock lies within 40 inches under 78% 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 Northern Mariana Islands, each drawn five feet deep from its official USDA description, in its recorded colors.

Chinen
19% of the area
Well drained
Mollisols
Luta
11% of the area
Well drained
Entisols
Takpochao
6% of the area
Very cobbly loam topsoil · well drained
A balanced mix that crumbles in your hand. The gardener's ideal.
Mollisols
Dandan
6% of the area
Clay loam topsoil · well drained
Firm and a little sticky. Holds water and nutrients well.
Inceptisols
Saipan
4% of the area
Clay topsoil · well drained
Sticky when wet and rock-hard when dry. Drains slowly.
Oxisols

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.

Northern Mariana Islands has 2 USDA soil survey areas covering a wide range of landscapes and soil conditions. The most common soil order is Mollisols — grassland soils with a thick, dark, fertile topsoil rich in organic matter, making up roughly 22% of surveyed soils. Entisols — young soils with little profile development, often on floodplains or steep slopes account for another 21%.

In terms of drainage, 89% of Northern Mariana Islands soils are classified as well drained. Drainage class affects everything from septic system design to basement feasibility to garden planning. Use the survey area pages below to see drainage details for specific counties, or look up any address for an exact soil profile.

Soil Types

Mollisols
22% of surveyed soils
Fertile grassland soils with thick, dark topsoil. Among the best for agriculture, building, and gardening.
Entisols
21% of surveyed soils
Young soils with little development — found on floodplains, dunes, and steep slopes. Properties vary widely by setting.
Andisols
20% of surveyed soils
Volcanic ash soils — light, porous, and fertile. Excellent drainage, but low density can complicate foundations.
Alfisols
20% of surveyed soils
Moderately weathered forest soils with clay-enriched subsoil. Productive for agriculture, generally good for building and septic.
Inceptisols
7% of surveyed soils
Young but developing soils found in mountains and river terraces. Variable properties — check drainage and bedrock depth.
Oxisols
6% of surveyed soils
Deeply weathered tropical soils. Nutrient-poor despite appearing lush. Rare in the continental US.
Histosols
1% of surveyed soils
Organic peat and muck soils formed in wetlands. Very poor for building (compressible) and septic. Often in regulated wetlands.

Survey Areas

Islands of Agrigan, Alamagan, Anatahan, Pagan, and Sarigan, Commonwealth of the Northern Mariana IslandsIslands of Aguijan, Rota, Saipan and Tinian, Commonwealth of the Northern Mariana Islands

Look Up a Specific Address

📍