I live in Tulsa, but I've never ridden around Bartlesville. Around here, most people go to Appalachia Bay or Whitewater, both of which are off of Keystone Lake (near Tulsa). They say Disney, OK, has some pretty gnarly stuff (rock crawlers usually go there, but there are some quads around). I went with some friends of mine down to Scipio, OK, and had a blast. I still haven't made it out to anywhere in AR, but there are several supposedly awesome spots there.
And I just got back from a trip to Red River, NM. What a great riding spot that is. I know it's a long ways, but you probably won't have any trouble finding OK locals willing to make the trip. In fact, that trip is what convinced me to start looking at buying a 700XX--my Outlander gets downright spooky when you get it very far off the ground.