The topography of the Duwamish drainage system in the Puget Sound is dominated by the Pacific on one side and the Cascade Mountains on the other. These topographic features had two main effects on the Duwamish. Also due to the topography of the area, the soil of the area is very wet and very fertile, supporting lush vegetation and much wildlife. The natural resources of the area provided the Duwamish with plentiful food resources. The natural abundance of the area allowed the Duwamish to specialize in subsistence methods and develop appropriate technology for each trade.
Archeological evidence shows the high level of technology for each trade specialty.
Men's trades included hunting, fishing and woodcarving. Women did weaving and food gathering with children. Controlled burning was used to clear land for farming and grazing. Although fish were plentiful year round and the growing season was seven to eight months, much food was stored, probably to support the high population density. The Duwamish population density was 16.8 people per square kilometer, as compared to the Iroquois 9.6 people per square kilometer.