Woodlawn, Virgina
The halfway point between Gulfport, Mississippi and Tulsa, Oklahoma is Varner, Arkansas. There is approximately 564 miles between Tulsa and Gulfport.
Greenfield, IN
Millington, Michigan.
The halfway point between Tulsa, OK and Fort Campbell, KY falls in or around Mountain View, MO.
Edwardsville, IL
Des Monien Iowa
Galena, OH
Tulsa, Oklahoma is close to the halfway point and is certainly worthy of a visit.
Urbana, Illinois.
There are no major cities between Akron and Parma via I77 S/N. The halfway point would be 20 miles, as the total trip is 40 miles.
The halfway point between Tulsa, Oklahoma, and Vicksburg, Mississippi, is Conway, Arkansas, if you're going via Fort Smith, Little Rock, and Pine Bluff.