Mark Hansen wrote:

There's an
airport near me that is charted as "Yuba County", but is called
"Marysville". When I was flying practice approaches into it (during
training) I called it Yuba County, and the controller just came back
with Marysville, so I started calling it Marysville as well.

73J, Beaufort, SC, is listed as "Beaufort County" but invariably referred to by
ATC as "Frogmore".