I have driven from Watson lake to Tok in the winter and all of the towns had gas stations open. If you are passing a town and your fuel tank is below 1/2 fill up. The gas stations that aren't at a town may or may not be open. The milepost helps some but there are visitor centers in most towns in the Yukon and they can help you with what is open. I expect you are coming up on the Alcan. The only place I would NOT get fuel is Muncho Lake area. I came through one year and they wanted $5.25 a liter. Stop at Toad River for food it is wonderful.