Aug 23, 2018  · Bay City State Recreation Area: Address, Phone Number, Bay City State Recreation Area Reviews: 4/5 The Upper Peninsula (UP), also known as Upper Michigan, is the northern of the two major peninsulas that make up the U.S. state of Michigan.The peninsula is bounded on the north by Lake Superior, on the east by the St. Marys River, on the southeast by Lake Michigan and Lake Huron, and…