The area referred to in the following summary of investigations includes the valley of the Tanana River, sections of the Central Yukon Valley above the mouth of the Tanana, and the upper Copper River Valley. This sub-arctic region, inhabited by bands of semi-nomadic Athapascan Indians, by white traders, trappers, miners, and only recently by a few farmers, presents unusual difficulties to an attempt to discover archaeological sites. This is due not only to the sparse population and limited cultivation but to the characteristic mantle of moss, brush and forest that obscures all evidence of ancient dwelling sites. No habitable caves or rock shelters have been found. Under these circumstances, investigations must depend primarily upon information obtained from the present natives and upon accidental discoveries made by white settlers in very limited cultivation and in placer mining operations.