6 miles South of I-40 and just at the edge of Hinton, OK is a small canyon with red and ochre colored walls. Stayed here on a week day so just a few campers here. Well spaced parking pads, 30 amp, water, cooking grill, large fire ring and picnic table for $30. Shower and restroom building adequately clean, but could use a new coat of white paint. Staff were very helpful on phone and in person. It appears to be a well run place. Worth the 6 mile drive from i-40 and a respite from wall to wall sites at some RV parks.
Ducking off i-40 to the North, Foss State Park was a great place to stay the night. Larger town of Clinton, just SE of the park.
Concrete pads, water, 50 amp, picnic table and a great (grate) fireplace. Small trees shade the pads. Dark night sky, except for small city lights to the North. The communication from the Park station was pleasant and responsive to inquiry. A little windy, but typical for OK. Worth the short drive from i-40.