 The city of Bainbridge Island has occupied the entire island since February 28, 1991, when the former city of Winslow (around 1.5 square miles (3.9 km2) of land on Eagle Harbor, incorporated August 9, 1947) annexed the rest of the island.Since the 1960s, Bainbridge Island has become an increasingly affluent bedroom community of Seattle, a 35-minute ride away on the Washington State Ferries.Bainbridge Island was formed during the last ice age—13,000 to 15,000 years ago—when the Vashon Glacier scraped out the Puget Sound and Hood Canal basins.