They last few trips we have made on the Cassiar Hwy have been in diesel powered vehicles. There are 4 or 5 stations that carry diesel. Northbound I usually fill up at the intersection at Kitwanga. Also a nice restaurant attached to the station. If you are going to take the side road into Stewart, BC, they also have diesel. Dease Lake has been a stop for us several times in the past. Several nice campgrounds in the area, plus the gas station - grocery store has an excellent deli. Bell II, roadhouse has diesel, as does Iskut and then at the far end where the Cassiar joins the Alaska Hwy about 13 miles north of Watson Lake.