"Entertaining" would be one way to put it. While I've led a few stock JK's through the park, none of them made it through completely unscathed. At a minimum, we tell folks to have skids, tow points, and something more aggressive than street tires.
It's possible to run the 'tourist' loop through the park, but there are quite a few places that'll get you in trouble. Here is the most recent map of the park:
http://www.aaronhull.com/misc/jeep/WashitaTrailMap.pdf
The tourist loop for a stocker would be Ground Pounder, Hamburger hill, to Brain Fart or Charlie Mike, up to the over watch (the knob/view). Come back down your choice of trail and going north to The Devils Playground and working your way back to the entrance from there. That loop will likely take you all day depending on how things go