The Animal Fence, Tigger
This is nothing sinister. It's can be very difficult to find farms out our way, there's nothing to mark the roads into the majority of farms. Mailboxes are clustered at intervals, not by the turnoff into a particular farm.
One household found this imaginative way to mark their turnoff, by wiring stuffed animals to their fence next to their turnoff road. (They have to be wired, winds in North Dakota are much too strong for anything else.)