They're a resource for trails and maps in your area. I checked on caltopo.com and gaiagps.com, there is the Mark Twain NF, and the Ozark National Scenic Waterway. Nat Geo has published several maps for MO and they are you're best bet for current trails.
Also caltop show a pretty good network in small parts of the Mark Twain NF. National Forests are the best because, you just go in....and camp...and have a nice campfire.* Lots of private land in that NF so you'll need a good map, also always good to check with the local NF website for any restrictions that might be in effect.
Here's a wide screen shot of the Nat Geo Map coverage in MO:
and here's zoomed in a bit:
looks like the current river trail could keep a person happy for a while.