Etymology and distribution of 大沢.

Oosawa 【大沢】^{レベル6
About 78,500}  The Japanese surnames etymology dictionary.

Aomori-ken , Aichi-ken , Mie-ken .

① Mie-ken Tsu-shi birthplace of birth. A place name with a record since the Kamakura period.

② Aomori-ken Kamikita-gun Originated from the part of Touhoku-machi . It is distributed in the same place.

③ Iwate-ken birth of Morioka-shi Oboe. A place name with a record since the Kamakura period.

④ Ainu system . Personal name . Hokkaidou Kushiroshi-chou Shibecha-chou 's otto is renamed to Isobe Itsuke. Estimated in around 1875.

Oozawa 【大沢】^{レベル6
About 78,500}  The Japanese surnames etymology dictionary.

乙馬 Otsuma reference.