Once at the posted coords, youll notice a couple signs next to the doors. Youll need to know what time the doors automatically lock to find the coords to the final.
If its 9pm use these coords N 43 46.901, W 71 42.801
If its 10pm use these coords N 43 46.902, W 71 42.802
If its 11pm use these coords N 43 46.148, W 71 42.846
If its 12pm use these coords N 43 46.903, W 71 42.804
Cache is less than a mile away in a light pole in a parking lot