The settlement specializing in iron products was found in Odate City from the settlements that had escaped the flood caused by the eruption of the volcano in Lake Towada-ko, thus demonstrating that the Emishi didn't need to obtain even iron from the Imperial Court.
十和田湖火山噴火に伴う洪水から高台に逃げ出した集落からは、専門に鉄製品を作っていた集落も発掘されており(大館市)蝦夷は鉄を朝廷側から得る必要も無かった。