Interesting John.
I fished the "way upper" Ruby two summers ago. I drove past all the great looking water due to the frequent postings of "No Tresspassing" and "Private Property".

I went way up to near the top where it was public.

The stream, at that point, was tiny and so were the fish!

It really hurt to drive back down the road into Enis and not be able to fish the good looking water which was marked "private".

It's all an age-old problem.

And, if one thinks water access is complicated, water rights tend to be even more complicated. Historically, I would say the case law tended to lean to property owners in both cases.