Where is this? Mystery Cache

You are looking for a green bison tube.  Just find this old Highway Survey Marker, and you will find the cache.  Cache is not at the posted coordinates, parking coordinates have been provided. Photo attached.

Now for the puzzle?

North 43 and West 79 assumed?

North

1.1 km = A

100.8 km = B

480 km = C

145.1 km - 1,780.2 km = ______ = D

100.8 km = E

N 4 3 A B . C D E

West

100.8 km = F

100.8 km = G

12.7 km = H

480 km = I

W 0 7 9   F G . H I 1

Good Luck and Happy Caching! 

You can check your answers for this puzzle on GeoChecker.com.