I've never personally camped up there but if you go a few km's passed the gun range you will come to a bridge you can go in there and get behind the river I've seen people camp there and you can also stay along the main road and you will see a little dirt track and I've seen people camp along the river across from that. If you do go up there be sure to check out Matheson falls
Just got back from holidays. Camping up Coal Creek is good to go. Lots of places just past the first bridge. The first bridge past Matheson is also cool. A left turn following Coal Creek down to some wicked pools for bathing and swimming is neat. I don't know if you can get all the way through as there was a bridge that was out further down the trail.
The burning coal seem is still burning and it is an easy hike. I forget the km marker but it should be around 37 km right at Aldridge Creek. Yes, you can drive very close along the power line. They may be active logging, so a VHF radio would be advised.
Fernie RV Resort has plenty of open sites left for the weekend according to their online availability calendar. They just opened this summer. Can visit their webpage at Fernie RV Resort - Western Canada's newest RV resort.
The Fernie Provincial Park campground also holds a number of spots for first come first serve (non-reservables).