A section can be made with restricted access, however: how do you choose who gets access?
There are a lot of good people who lurk (lurk: read and don't post). Hi, people who lurk!
On the other hand, having a login is no indication of upstanding nature... since anyone can join (avowed interest in SMBs or not) a simple username is setting the bar too low.
I'm not talking about a technical issue, it's a social one... how and who decides. I can provide the tools, but I don't have time to manage things.
My second thought is the consistency of the information. Personally I want GPS coordinates. Coordinates of the spot I'm camping on, no more no less. Maybe the waypoint of a turn or two and that's it. I don't even care what's there, I'll go on coordinates alone. Others will want to know what makes a spot great, or better directions.
How to make the information consistent, s.t. complete information is provided for every spot and people don't get frustrated trying to interpret, or trying to find places relevant to their trip. And so that people providing secret spots know what to include. I recommend looking at GeoCaching sites for ideas on information organization.
The non-technical solution to the second part would be to have the section heavily moderated, probably by the same group who decides and grants access. The technical one would be to build a custom tool for storage and interpretation of the data.
I'd suggest those interested start a thread in Forum Problems Comments and Suggestions on how it should work, PM me with any technical questions and if it gathers enough interest we can put something together.
Or maybe I'm over thinking it as usual- those are the ways I would run it, and I don't want to run it (plus I'm insanely busy), so if someone wants to take on this project just let me know what I can do to help.