I have talked to his family quite a bit with the idea that I wanted to find out more about the relationship with his dad. From what I can see the relationship was pretty violate though the significance of it is really unknown even to the family. His family did a DNA test not too long ago which found no other unknown family members.
As for Mary's family. I did ancestry research on them and I can see that she has a sister that may still be alive. Her sister would be in her 60s and she has grandchildren as well. As for Mary herself, I really could not find anything on her at all, I know her birthdate and when she married Raymond, but thats about it. Someone on another forum mentioned that she had a SSN issued in 1973? I get the feeling that she was not close with her family at all.
On the whereaboutsunknown page, someone pointed out that a Raymond D Harris married a Floy Marie Shull on November 26, 1971 in Las Vegas, Nevada. Out of sheer curiosity, I looked into this angle, but not enough to go down an unnecessary rabbit hole. The fact is that theirs probably tons of Raymond Dale Harris's in the US. If the missing date is November 26, 1971, then theirs no way that he would have got married on that date, especially since Las Vegas is about a 20 hour drive from Nebraska. This would change the last seen date to about...idk 2 or 3 days prior?
In my opinion, the key to really unlocking this case goes back to the car. If my memory is right, he basically had a brand new car when he went missing, so it would be imperative to know the vinn number and perhaps see if the car was ever de-registered. Obviously historical DMV records only go back so far, so I think law enforcement would have to dig through any sort of records if they still exist.
My thoughts are that he had an argument with his father that night and then drove to Iowa. Their no doubt would have been moisture on the ground so him hitting a stretch of black ice is a very real possibility. Combined with the fact that he could have had other things on his mind. I think some of the creeks on 80 would have been there though I am not from Nebraska lol.
Also we did do an FOIA in his case and heard back from Omaha the same day. They declined it basically because they did not want to send it to me. lol!