Thank you for your question, Dave.  I can't see the mature trees in your photos, so can't provide much feedback about them.  I believe what you are observing here is a condition called "flagging", which is becoming common in evergreens in these hot, dry times.  Here is a diagnostic resource describing the causes, with a couple of recommendations:  https://pnwhandbooks.org/plantdisease/host-disease/cedar-cedrus-spp-cedar-flagging
I hope this is helpful.  Good luck!

Here are pics of the mature tree.

Thanks!  Exactly as you can see here:  https://extension.oregonstate.edu/ask-expert/featured/my-cedar-dying

Thanks for the quick follow up.



Happy to help!  And that last post was written by our best forestry expert!