Near Lake Wisconsin, the highway turns east and then back north before sticking to an eastward course along a bend in the river. At the intersection with WIS 113 near the Merrimac Ferry, WIS 188 terminates.
In the vicinity of Lake Wisconsin, the highway makes an eastward turn followed by a northward one before following an eastward path along a bend in the river.  At the junction with WIS 113 near the Merrimac Ferry, WIS 188 terminates.