The Rosie's came to South Manitou Island from Macatawa (Holland, Michigan) in 1935. Ronald Rosie Sr. had been appointed 1st Assistant Lightkeeper on south Manitou as his first assignment, joining Keeper John Tobin and 2nd Assistant Ray Robinette. The family - Ronald, Johanna, and their two young boys Ronny and his two-year old brother Roger - came to the island aboard the lighthouse tender Marigold and moved into the keepers' quarters. They were the last family to occupy the house.
Ronald Jr. was 11-years old at the time. The boys were entrolled in the island's little school, under teacher Lenore Plowman. A love affair with Willie Beck's handyman Johnny Tucker culminated in a quick marriage, with Miss Plowman being replaced by Iola Tobin. Ronald graduated from the eighth grade three years later. He was fourteen.
In the winter of 1941, the tender returned to take the Rosie family to their next assignment, Ronald Sr. having been transferred to one of South Manitou's sister lights, the Seul Choix Point Light at Gulliver, Michigan on the southern coast of the Upper Penninsula, almost due north from the island. Four years later he was promoted to Keeper, and he served in that capacity until retiring in 1946.