This river's widest point, 3 1/2 miles, is just north of Clinton, Iowa
[DOC] [TLE] Mississippi River - Iowa Department of Natural Resources [PAR] Located between Clinton and Davenport, starts at River Mile 522.5, 10291.00 ... 
From north to south along our entire border, the river becomes systematically 
wider ... of a huge pearl button industry, the largest in the world, centered at 
Muscatine.