MHSST is a diocesan School owned by th Roman Catholic Church of the Diocese of Tagum. It was founded in 1961 by Rev. Fr. Walter Maxcy, M.M., a Maryknoll Missionary. Fr. Maxcy served as the first school administrator at the same time parish priest of Sto. Tomas. In 1962 the Maryknoll Sisters arrived, direct administration of the school was turned over to them with the parish priest serving as the director of the school. Sr. Rose Karen, M.M. served as principal from 1962 to 1967, followed by Sr. Marie Eugenie, M.M. who served until SY: 1968-69. The following school year Sr. Irene Mahoney, M.M. succeeded. In SY: 1970-71 Sr. Dolores Mitch, M.M. took over as principal and remained till SY: 1973-74. It was during her administration that the Maryknoll Sisters began a program of preparing lay teachers to take over the administration of the school. In SY: 1973-74 Mr. Numeriano Evasco took over the principalship of the school with Sr. Dolores Mitch as directress. The following year Mr. Evasco assumed the directorship of the school. It was during this year that the Maryknoll Sisters left the school to concentrate on other apostolates. Mr Evasco however, resigned at the end of the school year hence, his assistant principal, Mr. Eulogio Piala was named director-principal. He remained in his position till 1976-77, but at the end of the school year he also resigned. In SY: 1977-78 the administration of the school was turned over to the Domincan Sisters of the Most Holy Rosary of the Philippines with Sr. Ma. Laurencia Camayudo, O.P. as directress/principal. It was during her administration that the school expanded to include the Grade School Department, which was successfully opened on June 1983.