That area is considered Huntingtown and has a 20639 zip code.
It's true - I've never seen a more screwed up boundary line than the one between Huntingtown and Prince Frederick. If you come down Dares Beach Road (which is Prince Frederick) and hang a left onto Wilson Road, you only go about 1/4 mile and it suddenly becomes Huntingtown. But yet, if you continue to travel down Dares Beach Road into Dares Beach itself, it remains Prince Frederick. It's almost as if Dares Beach Road provides the boundary between Huntingtown to the left and Prince Frederick to the right. Very strange...
But if you look up Tom Clancy's house in the Assessments and Taxation database online, it is technically considered Huntingtown. It's just not the Huntingtown everyone pictures (as in Cox Road/Huntingtown High School).
Incidentally, he owns 80 +/- acres at the end of Camp Kaufmann road only. He may own other properties in the area (which you can find out easily enough but I'm not tellin' -

- not that anybody should care) but they aren't on that road.