Turns out, Spark was found by a local family about 3 miles away last night at 8 PM.  The wife immediately logged him on NextDoor as a Found Pet.  Well, in addition to walking the woods for hours, we had knocked on neighborhood doors in neighborhoods adjacent to the property.  One kind woman had her husband post on NextDoor about a lost pet. This morning, the link was established and we got the call.  We had created the poster from PetLink, had posted it on social media, and were about to post on our road and around other businesses when we got the call.  Use every resource you have – PetLink is a great tool, but don’t rely on just one.