It is supposed that, the Ando clan's territory during the late Kamakura period to the period of the Northern and Southern Courts consisted of the major part of the coastal regions except for the vicinity of current Hachinohe, Aomori Prefecture, according to the documents such as a letter of concession by Munenori ANDO (the widely-accepted theory is that it was the same person as the above mentioned Suehisa) and Akiie KITABATAKE's certificate for the land directed to Morosue ANDO, in which it is mentioned that the clan was in charge of Jitoondaikan (deputy military governor) in Kinuka-jima, Shirihiki-go and Ikunobe-go, Ezo no sata of Hanawa County, Mutsu Province and in Usori-go, Nakahama-mimaki and Minato Tsugaru-nishihama of Nukabe County, Mutsu Province, and others.
鎌倉末期から南北朝時代における安東氏の支配領域は、安藤宗季（上記の季久とする説が有力）による譲り状や安藤師季に対する北畠顕家安堵状によると、陸奥国鼻和郡絹家島、尻引郷、行野辺郷、蝦夷の沙汰、糠部郡宇曾利郷、中浜御牧、湊、津軽西浜以下の地頭御代官職となっており、現在の青森県地方のうち八戸近辺を除く沿岸部のほとんどと推定されている。