New to PQ Riding... confused

Hello
I have been on a couple rides out on the PQ canyon/Del Mar Mesa after moving back to San Diego (gone for about 8 years).
I never really rode up here before since I lived down south last time but now I live right on the canyon so it seems perfect but I have no idea what is legal and not.
I went out today and rode sepcifically looking for trails that had signs indicating that they are closed. I saw the entrances to tunnels 5 and 3 and the exit from 4 (as you guys have on the maps here) and none of these areas have signs indicating that they are off limits. I saw one sign hanging on a fence post where it was obvious you should not go (but some have recently!).
So... what is deal on the tunnels? If they are closed, where does it indicate that?
Thanks for the clarity and also for all the work you have done to keep them open!
Tom

[Robo]

It is confusing as nothing is signed very well. Everything in Del Mar Mesa Preserve is closed right now except the SDG&E service road.

Once the trail plan gets through all its official hoops, signage will be installed...and unfortunately probably fencing.

Without the addition of Mesa Loop and Tunnel 3 to the trail plan, I think it will be unmanageable and I will not support it.