The coordinates listed are for the first stage and at the
first stage you are looking for last date on this historic marker,
then to find stage 2 you will need to do the following:
N 36 18.( last three numbers of the last date on the board then
add 106)
W 082 21.( last three numbers of the last date on the board
and then subtract 429.)
Once at Stage Two you will again come to another historic marker
and you take the very top date and do the following:
N 36 18.( the last three numbers on the board and add
53)
W 082 22.( the last three numbers on the board and subtract
823.)
The final is a bag under a brick.
You can check your answers for this puzzle on
Geochecker.com.