Where did the Clampetts come from?

I just saw the pilot film, where Mr. Brewster, the head of the oil company that made the Clampetts rich, had his headquarters in Tulsa, which should be Tulsa, Oklahoma.

And Cousin Pearl reminds Jed of the time his pa took them to Eureka Springs to see a motion picture. Thee is a real Eureka Springs in the Ozark Mountains of northwest Arkansas, and about 110 miles east of Tulsa, Oklahima. So in the pilot episode the Clampetts should have come from someplace close to Eureka Springs.

Eureka Springs is about 20 miles east of several larger towns like Bella Vista, Bentonville, Rogers, Spingdale, Fayetteville, etc. which have grown together into a single ubanized area. So the Clampett homestead would probably be east of Eureka Springs instead of west of it.

Of course that doesn't guarantee that other Beverly Hillbillies episodes didn't indicate that the Clampetts came from somewher else.

The Beveraly Hillbillies had characters in common with Petticoat Junction and Green Acres, and maybe the Clampetts from the same region those shows were set in. So some of the hundreds of episodes of those three series should have had clues to the Clampetts home region.