In 1897, the Michigan State legislature enabled the formation of corporations in order to build resorts. In 1902, the Sunnyside Assembly purchased the land on the northwest side of Portage Lake that had formerly belonged to the Marvins. They changed the name of their organization to the Portage Point Assembly and incorporated it on 31 January 1902 under the special 1897 act of the Michigan legislature for building a resort, and immediately began to build the Portage Point Inn on 12 July 1902.
The following year, the building first opened for guests on 20 June 1903. By 1914, the Portage Point Inn was served by the steamships of the Northern Michigan Transportation Company, providing direct service from Chicago, Illinois and Milwaukee, Wisconsin. At this time and for the next 50 years, Portage Point Inn was a go-to destination for anyone looking for a Northern Michigan vacation.
Today the resort still entertains visitors throughout the season, and new development plans are in place to fully restore and enhance many of the amenities onsite.