You should include Sugarloaf Mountain Natural Area to your list of things to do near Marquette MI.
One of the most well-known picturesque viewpoints on the central Upper Peninsula shoreline, it is only six miles north of downtown Marquette, and the view is well worth the climb. From Marquette, travel up Sugarloaf Mountain via Big Bay Road. There are two options. Choose one that suits you best from one that is brief and somewhat difficult to one that is longer but easier.