Soil survey area

North Ogilvie Mountains - Step Mountains Area, Alaska

Survey Area AK792• Alaska
The short version

The most common soil here is E31-Boreal forest-loamy eolian slopes, on about 31% of the land. E31-Boreal taiga-silty frozen slopes and E31-Boreal taiga-silty frozen loess slopes come next.

About 74% of the land drains well, and 26% stays wet for long stretches; groundwater comes within two feet of the surface under 98% of it.

USDA rates all of the land very limited for a standard septic drain field, and 33% very limited for homes with basements. That means extra cost or special design, not that it can't be done.

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 biggest mapped areas

The dominant drainage class is Well drained and the dominant hydrologic group is B (moderate infiltration). The most common soil order is Gelisols — permafrost soils found in very cold climates. This report summarizes the major soil map units across the survey area to help you understand what to expect when buying, building, or gardening in North Ogilvie Mountains - Step Mountains Area, Alaska. Search your address to find the exact soil composition, drainage, and series details at your specific location.

Soil Map UnitAcresDrainageHydro GroupDwellingsSeptic
Interior Alaska Highlands-Boreal Upland and Subalpine-Rounded Mountains 157K Well drainedBNot limitedVery limited
Interior Alaska Highlands-Boreal Upland-Hills and Plains 45K Poorly drainedDVery limitedVery limited
Interior Alaska Highlands-Boreal Lowland-Flood Plains and Terraces 16K Poorly drainedDVery limitedVery limited
Interior Alaska Highlands-Boreal Upland-Rounded Mountains, Acid 11K Well drainedAVery limitedVery limited
Interior Alaska Highlands-Boreal Alpine and Upland-Rugged Mountains 5K Well drainedBVery limitedVery limited

Soil Orders in This Area

The USDA classifies every soil into one of 12 soil orders. Here are the dominant orders found in this survey area.

Gelisols
Permafrost soils. Extremely challenging for construction and septic. Found almost exclusively in Alaska.
Inceptisols
Young but developing soils found in mountains and river terraces. Variable properties — check drainage and bedrock depth.
Spodosols
Acidic forest soils with a leached layer. Common under conifers. Often have drainage issues from a compacted subsoil layer.
Entisols
Young soils with little development — found on floodplains, dunes, and steep slopes. Properties vary widely by setting.

What This Means

Building & Foundations

About 33% of soils have significant building limitations, while the rest are generally suitable. Check specific sites carefully — conditions vary across the area.

Septic Systems

About 100% of soils are rated "very limited" for septic absorption fields. Despite good drainage overall, limitations may stem from shallow bedrock, steep slopes, or seasonal conditions. Engineered or alternative systems are frequently required. Always get a professional perc test before purchasing land that needs septic.

Gardening & Agriculture

Well-drained soils on sloped terrain — good for most plants but watch for erosion. Terracing, contour planting, and mulching help retain moisture and topsoil. Drip irrigation is more effective than sprinklers on slopes.

Look Up a Specific Address

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