The coordinates above will take you to a circle of rock pillars, some of them are reasonably whole, while others barely can be seen. From here, you need to follow the clue below:
You stand with your feet where they could get burns,
Face the twin tree with yellow making no turns.
You put your arm out at 'bout 2 o'clock,
Your next destination is a small rock.
Right now you can't see it, but it's still there,
It's blocked by fallen tree with arm in the air.
Stand on the rock with your back to the arm,
Just 90 more feet, you're getting quite warm.
Look a bit to your left, you prob'ly see it,
From the bottom of a tree you must free it.
It's hidden very well, put it back w' care
Please make sure it seems no one's been there.
WARNING: The cheater hint is really a spoiler -- it gives the actual coordinates -- it will really ruin your fun if you use it. Those who did this at the picnic agreed that it could and should be done without it. (Believe me, when you're there, this isn't nearly as hard as it may sound).