Take Mississippi River Road north out of Keokuk and just follow the road until you get to Montrose. For a longer ride you can follow Mississippi River Road through Montrose to Hwy 61, ride 61 to the town of Ft. Madison. On the east end of Ft. Madison take the bridge and take 96 South back down the Illinois side of the river (not marked).
Much of this ride runs along side the Mississippi River. You will see barges, trains, and an old school house just to mention a few things. a few miles take you just west of the river through a very small town (Sandusky) and past farm fields and a coal terminal.
This road has many curves and hills. I cannot speak for the road quality right now becuase it is under some construction but as soon as the construction is finished I will update.
Some restaurants in Keokuk. Montrose has a meat market and tattoo shop. Keokuk has Honda and Kawasaki stores. The closest Harley store is 30 miles away in Burlington IA.