South River to Stonecliffe is tight for gas, depending on your sled and driving habits it may be possible but you might be on fumes or worse near Stonecliffe. To make it through, there is a gas station on D trail just past the junction of D trail and A101D called Chisholm Country Market. You can gas up or top up there and then the run to Stonecliffe is doable without going into Mattawa. As you travel north on D Trail, stay left when you meet the rail trail, the right turn would put you on A101D towards Mattawa. The gas station is about 4 or 5 clicks up D trail. They have limited opening hours so check ahead to make sure they are open when you plan to make the trip.