Data from the Jomon period (ca. 16,000–2,500 cal. B.P.) of the Japanese archipelago offer a unique opportunity to examine both short- and long-term changes in human-environment interaction. Scientists have suggested that climate changes, which affected vegetation and the availability of both terrestrial and marine resources, must have been closely linked with the changes in the Jomon culture. Scholars have also investigated the importance of human impacts on the Jomon landscape at the local or regional levels. Chronological resolution of these analyses has become a key issue in examining both climatic and archaeological data. Using data from Sannai Maruyama and its neighboring sites in Aomori, northern Japan, this paper examines three factors that seem to have been closely related to the growth and decline of large Middle Jomon sites in this region: 1) climate change, 2) human impacts on the landscape, and 3) subsistence specialization. In particular, we hypothesize that subsistence specialization was a key factor in allowing settlement growth but at the same time it increased vulnerability to environmental changes. Through these discussions, it is suggested that the examination of the interrelation of these factors is indispensable to our understanding of the mechanisms of long-term culture change.