It's really hard to find info on area trails. I guess the best thing is to contact a local atv club. With that said. If you want to ride trails in the Missoula area the closest is the trail on blue mountain. The trail starts about 13 or so miles up the mountain. It is a decent ride. Many miles of trail. Otherwise there is the overwhich trail in the Westfork west of Darby or the chain of lakes trail in the Eastfork East of Sula. Both are really fun - The Chain of lakes trail has lots of trails that are not on the map. More difficult than the other rides. If you use Google earth you can see most of the trails - you have to look closely though. Be careful on this ride. Most is easy enough, but there are a few spots you need to pay attention.