Last fall the mine was operating but I'm pretty sure they don't provide any services for the public. If you were desperate perhaps, they might sell you some fuel but I wouldn't count on it. I also heard several months ago that the mine was closing again. I have no idea if that was true or not.
I wouldn't worry too much about going it alone down these roads. They are in pretty decent shape. As long as you plan your fuel carefully and drive sensibly you should have no problems.
I always thought Tungsten was a town and people lived there...which meant services were provided.
I guess what I'm concerned about is the unforeseen breakdown one might have on one of these roads. You can't be sure when you might see someone else on the road who might come to your rescue.