As you will hopefully see for yourself when you visit the cache, the inscription on the engraved plaque at the site of the cache reads the following:
"One hundred twenty-two rods west by north from this stone lived the famous Indian fighter Colonel Benjamin Church."
In terms of who Benjamin Church is, he is considered to be the father of American ranging and captain of the first Ranger force in America. His war tactics were essential in wars about Indians, specifically during King Phillip's War, and he was later employed to fight in more wars later on.
You shouldn't have much trouble finding the cache, but be careful of the road. It's busy, so make sure to pull all the way off. Take some time to appreciate the area while you're here too. Hope you enjoy!