Funny you mention on OU - we visited. At the time, my son was leaning toward atmospheric sciences as a major and OU is tops.
Their visit day - the set up, the individualization is tops - they are really good at marketing and following through. I wanted to be a Sooner after our visit 
He’s got a lot of great choices ahead.
Good luck to him.
The main thing is - just to ensure you have a back up - wherever it is. Purdue is not a back up for engineering. It’s almost a peer. So like a Pitt.
btw - last time I checked Michigan is West of Cleveland.