Here I am again. Replying to yet another ancient thread. Just can't help myself I guess.
The White Stag (or White Hart) came to this country on the ships that brought emmigrants from the British Isles and Northern Europe. Unlike the other livestock, however, the White Stag made the trip in the heads of the human travelers. In Europe in general, and in Britain in particular, the White Stag was an important part of folk culture.
My grasp of Celtic gods and Arthurian romance isn't what it used to be so if you really want to look into the origins of this mythical beast you should go to this page:
http://www.everything2.com/index.pl?node=White Hart
Briefly, the white stag is always an indicator of the supernatural. Typically it is either a warning that you have crossed a boundary best left uncrossed or, annoyingly, a sign that you should follow. JRR Tolien uses the stag in the first way in The Hobbit. Bilbo Baggins and the Dwarves go after a white stag that is "property" of the elves in Mirkwood and end up lost and in trouble. On the other hamd, C.S. Lewis uses the White Stag as something to follow when it leads the four children, by then 20 and 30 something kings and queens of Narnia, back to the Lamp Post and the portal to the "real" world.
I'm told that the pines were a sort of crossroads where folk cultures from New England, The South and the Mid-Atlantic met and mixed. This, I think, helped out by the local deer population possibly producing piebald or albino individuals, make White Stag stories almost unavoidable in the region.
This may not have helped, but it was sort of fun.
Best
relayer