Boreal forest is the dominant vegetation in the subarctic zone; it accounts for 50% of the land area in Alaska. Black spruce (Picea mariana) dominated stands are considered the climax successional stage in the Alaska boreal forest. Commonly, black spruce is believed to occupy only cold and wet sites. However, soils studies associated with the UAF-AFES Forest Growth and Yield Program in interior Alaska, found black spruce forests growing on a wide variety of landscape positions from somewhat excessively drained sand dunes, well drained ridge tops, to poorly drained lowlands. Soils associated with black spruce were studied along both north-south and east-west transects. Their morphological, physical and chemical properties were characterized. Organic horizon thickness ranged from 4-18 cm. on well drained sites to > 30 cm. on poorly drained sites. Generally, soil pH increased with depth: from 4.0-6.0 in O horizons, 4.0-6.0 in A horizons, 5.0-7.0 in B horizons, and 7.0-8.0 in C horizons. Total soil carbon, generally, decreased sharply with depth from about 30-50% in O horizons to < 1.0% in BC and C horizons. Wildfire is a common and frequent disturbance feature in black spruce forests in the western boreal region; thus, charcoal was found throughout the soil profiles with a concentration in surface and subsurface horizons. This charred material often leads to an overestimation of soil organic matter and yields a wide C:N ratio.