Boyce was a multi-millionaire by the early 1900s and by 1909 became more interested in civic affairs and less in finance. He also began to travel, often as part of hunting expeditions. He leased hunting lodges at Fort Sisseton, South Dakota, where he had hunted as a young man. He often hosted friends and relatives, especially his son, for activities such as hunting, fishing, dinner, poker, and plentiful liquor. These changes may have been in part caused by the destruction of his Ottawa mansion by fire in early 1908, which was soon rebuilt, followed three months later by the sale of his Marseilles paper mill due to a new law that prevented railroads from negotiating with shippers, and his September 1908 announcement that he and his wife, Mary Jane, were separating.