The soils occur under cold continental and cold maritime climates. Mean annual air temperatures range from 18x to 28xF, and mean annual precipitation ranges from 12 to 25 inches. These include the Kuslina, Nome, and Tupuknuk series, the Inmachuk, Lemeta, Sus tna, and Takotna series, and a wide range of well drained soils of uplands, including Cryorthents, Cryochrepts, Kuskokwim SerieS Page 3 Cryumbrepts, and Cryorthods. The Inmachuk and Lemeta soils are deep Fibrists. The Susitna and Takotna soils are well drained stratified sandy and silty soils of floodplains.
Internal drainage is blocked by permafrost.
In places, the soils support a forest of black spruce. The series is very extensive in the zones of continuous and discontinuous permafrost.