Last month, he was doing a bit of digging when he found, of all things, a keyring from Radio Kerry dating from the 1990s.
Henningfield has never been to Ireland and had never heard of the station but after a bit of digging (pun intended) online, found their Tralee address and posted the keyring over with a note explaining how he found it.
Jeff bought the farm 11 years ago and says he has no idea how it came to be on his land as he says it’s not an area of the US where many Irish people have settled over the years.
"How a keyring from the country of Ireland ended up buried in one of my out buildings is the mystery that we’re not gonna solve," he told the station.
BUT if you have any theories, we would love to hear them. Let us know in the comments.