One big city that is halfway between California and Ohio is Amarillo, TX.
Another is Oklahoma City, Oklahoma.
Not as big but almost exactly halfway is Elk City, Oklahoma.
Sugar Grove, Ohio is the halfway point.
The halfway point is Eastcleft, Ohio.
Altoona, Pennsylvania is halfway between Hartford and Columbus
Johnson city.
The halfway point between Pelham Drive, Fort Wayne Indiana, and Toledo, Ohio falls in or around Defiance, Ohio. There is no city of Pelham.
The city of Berea, Kentucky is halfway between Atlanta, Georgia and Columbus, Ohio.
The city that is the halfway point between Downey, California and San Francisco, California is Acebedo, California. It is the exact geographical halfway point.
The halfway point between Grandville and Hershey is Breakman, Ohio
Hudsonburg, TN.
Approximately Toledo, Ohio.
Terre Haute, IN
Charleston, wv