The geocache is not at the posted coordinates.  

In order to find this Bonus Cache you must have finished the Witt's Safari Adventure.

https://labs.geocaching.com/goto/ranger  You need to have the Geocaching Adventures App on your smartphone to play.  Once you've finished the adventure, write about your experience in the Witt's Safari Adventure Logbook. 

Welcome to Witt's Swamp Trail system. This is actually Witt's End Trail. Visit https://www.wfltmaine.org/witt-swamp to read the Western Maine Land Trust website and see trail map. The trail map is on the official geocaching app. Great place for a hike, snow shoe, or mountain biking.I hope you enjoyed your walk on the trails today. 

I hope you come back.