Nulato Hills - Continental Divide and Blackburn Hills Area, Alaska

Survey Area AK728• Alaska

The dominant drainage class is Well drained and the dominant hydrologic group is B (moderate infiltration). The most common soil order is Inceptisols — young soils with minimal horizon development but more than Entisols. 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 Nulato Hills - Continental Divide and Blackburn Hills Area, Alaska. Search your address to find the exact soil composition, drainage, and series details at your specific location.

Soil Map Unit	Acres	Drainage	Hydro Group	Dwellings	Septic
Yukon-Kuskokwim Highlands-Boreal Upland and Alpine-Rounded Mountains	1.1M	Well drained	B	Very limited	Very limited
Seward Peninsula Highlands-Arctic Upland-Loess Plains	829K	Very poorly drained	B/D	Very limited	Very limited
Yukon-Kuskokwim Highlands-Boreal Upland-Rounded Mountains	692K	Well drained	B	Very limited	Very limited
Yukon-Kuskokwim Highlands-Boreal Alpine and Subalpine-Rounded Mountains	291K	Well drained	B	Very limited	Very limited
Seward Peninsula Highlands-Arctic Upland-Rounded Mountains, Acid	257K	Moderately well drained	C	Very limited	Very limited
Northern Seward Peninsula-Selawik Lowlands-Arctic Upland-Plains, Gravelly	214K	Very poorly drained	D	Very limited	Very limited
Arctic Coastal Plain-Arctic Lowland-Coastal Plains, Low	177K	Very poorly drained	D	Very limited	Very limited
Seward Peninsula Highlands-Arctic Upland-Hills and Plains, Gravelly	156K	Very poorly drained	D	Very limited	Very limited
Ungalik-Tenmileriver complex, 10 to 35 percent slopes	144K	Well drained	B	Very limited	Very limited
Igniq-Tikigak-Uvluutit complex, 6 to 20 percent slopes	139K	Well drained	B/D	Very limited	Very limited
Urgiilik-Silagiksaak association, 5 to 50 percent slopes	124K	Well drained	C	Very limited	Very limited
Yukon-Kuskokwim Highlands-Boreal Upland-Valleys	118K	Poorly drained	D	Very limited	Very limited
Yukon-Kuskokwim Highlands, Boreal Hills	113K	Well drained	D	Very limited	Very limited
Nulato Hills-Southern Seward Peninsula Highlands-Boreal Upland and Maritime Upland-Rounded Mountains	111K	Well drained	B	Very limited	Very limited
Seward Peninsula Highlands-Arctic Upland-Rounded Mountains	103K	Well drained	B	Very limited	Very limited
Urgiilik-Nunanjiak complex, 15 to 45 percent slopes	100K	Well drained	B	Very limited	Very limited
Interior Alaska Lowlands-Boreal Lowland-Flood Plains and Terraces	97K	Poorly drained	B	Very limited	Very limited
Tikigak-Ungalik complex, 10 to 45 percent slopes	86K	Well drained	B	Very limited	Very limited
Kikku-Nagruk complex, 0 to 20 percent slopes	86K	Very poorly drained	A/D	Very limited	Very limited
Tui-Tumi-Iyyagrik complex, 15 to 70 percent slopes	83K	Well drained	B	Very limited	Very 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.

Inceptisols

Young but developing soils found in mountains and river terraces. Variable properties — check drainage and bedrock depth.

Gelisols

Permafrost soils. Extremely challenging for construction and septic. Found almost exclusively in Alaska.

Mollisols

Fertile grassland soils with thick, dark topsoil. Among the best for agriculture, building, and gardening.

Entisols

Young soils with little development — found on floodplains, dunes, and steep slopes. Properties vary widely by setting.

What This Means

Building & Foundations

About 100% of soils are rated "very limited" for dwellings with basements. Specific challenges include steep slopes, poor drainage in some areas, flood-prone areas. A geotechnical assessment is recommended before building.

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.