1. You will need to take the letters from the upper portion of the puzzle and place them into the lower answer grid.
2. The letters in each column will fall down into the same column in the answer grid, although not necessarily in the same order.
3. Each black square in the Answer Grid represents a space in the message. Punctuation marks in the puzzle will not be replaced by letters.
4. Each letter will be used once.
5. Words MAY carry over from one row to another. The only divider between words are black squares. Read left to right, the words reveal the correct coordinates of this mystery cache.
More information and puzzle-solving strategy can be found in on the "Related Web Page" link above.
You can validate your puzzle solution with certitude.
Thanks to Spotteddrafter for testing an earlier version of the puzzle.