Would it be easier to float in the great salt lake or Lake Michigan?
The Great Salt Lake. The Great Salt Lake has such a high salt concentration that it is easy to float. In fact, the old slogan of the Saltair Resort (a tourist spot at the Great Salt Lake) was "Try to Sink!!"
Michigan (MI) has land borders with Ohio, Indiana, and Wisconsin. The closest state without physically touching Michigan is Illinois. However, Michigan also shares water borders with Minnesota and Illinois across the Great Lakes. Taking this into account, the closest state without bordering Michigan would be Pennsylvania.