The northern section of the US state of Michigan that is separated from the southern part of the state by Lake Michigan, the Straits of Mackinac, and Lake Huron. Lake Superior is to the north.
Definition of Upper Peninsula in US English:
Upper Peninsula
proper noun
The northern section of Michigan that is separated from the southern part of the state by Lake Michigan, the Straits of Mackinac, and Lake Huron. Lake Superior is to the north.