The jurisdictional area corresponds to Oshima Province, eight counties of Shiribeshi Province (Kudo County, Okushiri County, Futoro County, Setana County, Suttsu County, Shimamaki County, Utasutsu County and Isoya County) and Yamagoe County of Iburi Province according to ryoseikoku (province).
管轄地域は令制国に従えば、渡島国と後志国の久遠郡・奥尻郡・太櫓郡・瀬棚郡・寿都郡・島牧郡・歌棄郡・磯谷郡の8郡、胆振国山越郡に相当する。