Tri-Cities 2021 Geocoin Challenge
History of the Tri-Cities

Land of the Three Rivers Bonus Cache

This is a Bonus Cache for the Land of the Three Rivers Adventure Lab, our 2020 Adventure Lab that took you around the Mid-Columbia. Once you have visited all the locations and collected all the clues, reconstruct the coordinates to the final location using the puzzle below. You can use the checker to verify the coordinates before heading out to find the cache.

Coordinates for the Bonus Cache:
N 46° 1A.BCD' W 119° 1E.FGH'

North	West
ABCD	EFGH

In order to calculate ABCD and EFGH color (unless otherwise indicated) the symbols or letters that correspond to the hints collected during the Adventure Labs. Math is required for both parts of the puzzle. You will need to identify the two historical numbering systems used for the two parts of the puzzle, looking towards Europe for the one, and towards Central America for the other.