This cache is not at the posted coordinates. Please don't go there, you will get wet for nothing.
This bonus cache can be found by completing the "Historical Forestville" Adventure Lab. Clues to the final coordinates will be revealed at each lonation along the adventure.
N35 57.ABC W78 30.DEF
With these coordinates, you will find the physical cache.
The cache difficulty reflects the difficulty to uncover the coordinates, not the hide. The terrain reflects the hide.