rookalunds: It's time to retire this one. It never was in a great spot, but the puzzle dictated that it be there. At first it was in a pine tree in a bison tube that was nearly impossible to find. Then Reston cut down the tree and I had to hide it in the ivy at the base of the former tree...even more impossible to find. Originally I intended it to be a hard puzzle and easy find. It turned out to be both.
For those who are still on the watch list who haven't solved it yet, the secret was in the last line of the last fact. The date 15-Dec-1791 is also the hexadecimal 15dec1791, which converts to decimal 5870720913. With the statement that N38 and W77 are assumed, that means the coordinates are N38 58.707 W 77 20.913 If you put it into Google Maps you'll see it was right on one of Reston's bike paths, right next to Reston Parkway and about 20 feet from the old Burger King drive through...not ideal but necessary given the puzzle.
Thanks to all finders, hunters and those who tried to solve. Cache on!