An hour's drive north into Ilinois past Alton and up to Grafton, Pierre Marquette State Park on state highway 100
Grafton, Illinois is a rivertown just a half hour's drive from downtown St. Louis. It sits on the Mississippi river, just like St. Louis and hundreds of smaller towns, most noteworthy being New Orleans which sits at the mouth of the Mississippi. The pictures here of Aries wine bar and Grafton's Landing marina are just a taste of Grafton, which has remade itself from a very sleepy rivertown to one of new condominiums, marina, restaurants and a small subdivision right on the river! The great river road, as highway 100 is called, is a treat all too itself on a sunny day as all the sailboats and boaters will be in the river.
While not the tourist find of the decade, don't expect too much, but if you can get around to the rivertowns near St. Louis like Grafton and Alton you can find river casinos, restaurants, craft shops galore. Not commercialized like so many strip malls, these are real towns with real locals. In Grafton, if you want to sample river fish, there are a few restaurants that cater to these exotic species, just ask, the town is not that big.
Take Interstate I-270 north to the newly refurbished McKinley bridge at the exit that has a small sign "McKinley bridge" and a reference to Illinois highway 3. The exit isn't far from the Gateway Arch, so if you have driven awhile and haven't seen the Salsbury exit you have to turn back and restart (no bike allowed on the interstate, but the McKineley bridge has a protected path on either side of the bridge for cyclists, walkers).
About a flat, straight north with no stops and 20 miles or so, you will come to Alton, Illinois. You will pass Fast Eddies bar and grill in Alton. Stop for that for sure unless you take a pass on biker bars, but it really has all sorts of folks that go there, even older folks with walkers have been seen there!
Keep the river in sight, Alton is the historic rivertown and one of the famous Lincoln-Douglas debates has a park devoted to the event. Try to get over to Illinois state highway 100 by the grain towers. A riverboat casino is nearby that too. Alton has its own new marina as well. Continue north to the small quaint town of Elsa and soon you will be to Grafton. If you want to go a little further north, you can catch the Brussels Ferry, a free one that will take you to Kinder's Restaurant on the river as well. You will need a detailed map of the area or just follow the signs to Kinders. The locals know all about it most likely.
Even further north of the ferry, is Pierre Marquette State Part which has lodging in the huge CCC depression era lodge on the river. Cabins exist too on the grounds. Rooms in the lodge go for about $80 a night but book fast so call ahead or just walk in and check on availability. I have gone to Yellowstone and CCC made lodges in Glacier Park and Pierre Marquette Lodge is as big as any of those you will see in the U.S.