What exactly are the rules for the St Helens area? Can we go anywhere we want? ATV trails? Can we plow over small trees and make new trails?

I was up there this weekend and since I only had 4 jeeps in my group I was able to explore some and it seems that there are large areas on St. Helens area with no trails. I saw a few places that might be worthy of exploration and was wondering just what is legal. It seems like theres lots of room for more trails there.