It has been about 2 years since I have last been through Mena, and 3 years since I was last at Queen Wilhelmina State Park in our coach, so some of this may have changed. When I was last there Hwy 71 for a few miles south of Mena was in what I would call fair to poor condition with some road construction signs, but no real construction activity. Getting from Mena to Queen Wilhelmina State Park, take Hwy 88 it is a twisty somewhat narrow scenic highway popular with motor cycle riders, but is better than the Hwy 59 / 272 option, as 272 is couple of miles of a narrow steep country road that you should not drive a 30 ft coach on (I know followed my GPS and that is the way it took me, not a good place to run into oncoming traffic, and I was worried about tail dragging). As to Oklahoma, I can't help other than to say that in general it seems Oklahoma has the worst roads in the region.
Attached is a picture of my coach at Queen Wilhelmina State park in the summer of 2017.
2002 Safari Trek 2830 on P32 Chassis with 8.1L w/ 400 watts solar
2017 Jeep Cherokee Overland TOAD with Even Brake,
Demco Commander tow bar and Blue Ox base plate