One More Island Post

If you've ever been out to the Island, you've seen initials and names carved in the building from everybody and their brother.  Some of them are actually pretty old, which is neat.  On the corner by the porch swing, though, there's another kind of graffiti of which, at this point, I know neither the origin or the meaning. 

Someone, at some point, nailed the numbers "194" and a symbol that looks vaguely like the Appalachian Trail logo into the log ends:

From the placement, it looks like the 194 should have been a date, with one more number at the end.  I don't know what the AT or TA might represent.

On the opposite corner of the porch, the initials C.A.D. were nailed into another log end.

Everyone loves a good mystery.  Once I figure this one out, I'll (of course!) let you know.