Forum Display Question

[husf]

Here's my situation. I have a message board that deals with a certain topic. This topic right now is geographically specific (California). I have forums that deal directly with the topic and I have forums that deal with general information that that isn't area specific.

I want to expand my board to other locations (Oregon and Washington) but I don't want the California, Oregon, and Washington specific forums to be visible at the same time unless someone wants to view the entire board.

What I'd like is to be able to have URLs like www.---.com/forum/California, www.----.com/forum/Oregon, and www.---.com/forum/Washington and have only the specific area topics visible on it's designated URL. In other words, I want the general topics to be displayed with all specific topics since users from all areas can benefit from the general topics, but not have all specific topics displayed at the same time on these URLs.

Is there something available that would allow me to do this? Any help would be greatly appreciated. I apologize if my explanation isn't clear. Thanks in advance!