When Masamune's territory changed to Iwadeyama-jo Castle in 1591, Sadatsuna was granted a territory of over 20 settlements (approx. 10,000 koku) in Isawa-gun, and became the castellan of the Maesawa-jo Castle.
1591年、政宗が岩出山城に転封されると、胆沢郡に20邑余（およそ10000石）の所領を与えられ、前沢城主となった。