Coordinates will take you to the Mullan Road informational sign at the EAST bound Drummond Area Rest Stop. From this sign you should be able to answer the following questions:
What year did construction begin?
What was the length of the road? [3 digits]
How many workmen constructed the road?
Having those answers you can determine:
A=last digit of length of road
B=second digit of number of workmen
C=first digit of year construction started
D=first digit of length of road
E=last digit of the Interstate that the Mullan Road follows
F=B+D
N46 AB.CDE W113 CF.CED