Awesome hiking locations near Oklahoma?

I and three friends are looking for somewhere to go hiking and camping, and we are located near Tulsa, Oklahoma. We want to hike up a mountain somewhere and camp on it. Two of us are relatively new to hiking, but we've camped quite a bit, and the other two have hiked many times. We could probably drive and excess of 500 miles or so to a spot, and then hike, but we are just looking for some tips and possible location suggestions. Thanks a lot!