“There was and is such a thing as a ‘footstone’ that marks the bottom of a burial site away from the head and main tombstone. Could be one of those.”
The original poster u/Jeromiewhalen then contacted the state’s Head Archaeologist and reported back, “It’s a gravestone for a child. They said, ‘This object appears to be a mid-late 19th-century headstone marking a child’s grave or some sort of cenotaph children’s memorial.
This general area of Conway State Forest is part of a former agricultural homestead landscape, so a poorly marked cemetery and/or cenotaph memorial near the former home site is not especially surprising. DCR staff have not yet systematically archaeologically surveyed this portion of Conway State Forest.’
I’m scheduling a time to go with the archeologist to return it.”
Later, they posted an update to the same comment: “The gravestone has been returned! Thank you to the Conway Historical Society and the Massachusetts State Archeologist team for meeting us to record its location and provide some historical background on the area.”