There is one place named Northumberland County Airport in America.
All places in the world called "Northumberland County Airport".
Riverside (46)
Centerville (43)
Fairview (40)
Midway (39)
Franklin (39)
Union (37)
Greenwood (37)
Glendale (36)
Salem (36)
Marion (36)
Lincoln (35)
Fairfield (35)
Pleasant Valley (35)
Georgetown (35)
Oakland (35)
Liberty (35)
Greenville (34)
Bethel (34)
Springfield (34)
Clinton (34)
Arlington (34)
Florence (34)
Clifton (33)
Milton (33)
Hamilton (33)
Newport (33)
Farmington (33)
Chester (33)
Kingston (33)
Lakeview (32)