 From 1947 to 1949, he also served as Apostolic Administrator of Okinawa and the Southern Islands, Japan, in addition to his work in Guam.Almost immediately after arriving on Guam, Baumgartner set to work reestablishing Catholic schools on the island, all of which had been destroyed in the war.He quickly arranged for nuns to set up houses on the island to staff his schools, while also hiring Chamorro lay teachers.