@PalmerLakeAnon you have a strength that is rarely seen!!! I'm amazed and impressed. And I know.inside you must be crumbling, but your ability to stay focused and be honest with the information is rare. And mom..... just hugs. I simply cannot imagine.
Now, to the helpful part. A few things. Anytime you are dealing with terrain issues, I always think that a more professional team might be needed. Has anyone contacted Tim Miller with Texas Equusearch yet? He might be a huge help or at least have resources.
I also know sometimes, there are local sar teams who will go above and beyond, help grid the area. If it is wooded area, drone searches might not be helpful, but there is also a huge surge in amateur drone operators who are so helpful! We have someone in our community helping us with an issue on the river. I had no idea how clearly they can see!
Also, look for a Facebook page for the hiking area (everything has a Facebook page now, right? Lol). First, let them know he's missing, so they can keep good eyes out for anything on hikes. Second, ask them for info on any caves or hidden areas around there. That should be ruled out first. No need to scour the world if he's right there. Third.... I am so so so sorry in advance to say this. I really am. Did anyone notice any rope missing? Be sure to look not only down, but up during searches.
Also, any recent bank transactions or purchased might be helpful.
I also have concerns that there could be a mental health breakdown here. But from working in mental health for 16 years, I know that often, drug episodes and mental health can mimic each other.
I really have more to say, but I know it's hard to read so much, so I will leave with those ideas and thoights, for now. Just know we are hwre! We are good behind the scenes workers! So if there is something we can help with, we will!! Just give us the word.