I was sent this article about Leslie, Timothy and Julie Guthrie, a mother and her two young children who dropped off the face of the earth in Katonah, New York in 1977. It reveals some more info on their disappearances. Among other items of note, it seems they disappeared on February 5, not February 6 as their NCMEC poster says. February 6 was the date they were reported missing.
It’s a strange case, with the lack of any evidence at all. Since Timothy Sr.’s been ruled out as a suspect, and there are no indications of foul play but no indications of a voluntary disappearance either, and since the car is missing, I wonder if it wasn’t a simple vehicular accident. I have no idea what the terrain is like in the Katonah area but wonder if Leslie possibly drove into a lake or river and their car is still submerged with them inside.
Fun fact: the “Detective DiBiase” quoted in the article is actually the younger brother of Tad DiBiase, aka the “No Body” guy.