This cache is not at the listed coordinates but it is nearby.
There's 2 ways to find this 'rock hard' cache.
1. Navigate to the listed coordinates and then search thousands of rocks within a 70m radius.
2. Solve the 3 step puzzle to obtain the final coordinates to reduce your search radius.
Either way it's going to take a while and mess with your head.
Please note the cache is not on the road as that would be dangerous. Use the listed access waypoint or if you choose to park by the highway be sure to pull well off to the side of the road.
Congratulations to BenM70 for 12 hours on the jigsaw plus more on the next steps and in the field to claim the FTF.
