The posted coordinates bring you to a sign. This sign and the next one on the trail to the west give the clues to the final cache.
1) Basket Sign - A = the number of items on the sign made from plant material
2) Adena Village (N39 07.156 W84 48.897)
A = the number of houses shown on the sign
Villages often contained X - 4 round huts .... Houses were GH' to B0' in diameter.
Y=H-G
The final is at:
N 39° 07.1AB W 084° 48.9XY
Sum check A+B=9 X+Y=9
The cache is a pelican box.