The "Far West" as you are refering to is actually in the ski area, and when it has enough snow (which is rare, and some years not at all) the resort opens it up. I would reccomend not going in until they open it, since they are very good at opening their runs when most resorts would say that there is still too little snow. The enitre west end area and lift offer most of the best riding on the mountain, but if you snowboard the catwalks can be very rough. The tree skiing is great and there are numerous boulder fields that need less snow that you can pretty easily find.
You can go beyond the Far West area, but it rarely has enough snow as well, and the amount of traversing you end up having to do isn't really worth it.