As pointed out by others, the route you asked about is a scenic and interesting route to follow. It is probably the route that will take the most time. As for the ferry crossings, depending on how you decide to go, there will be either one or two crossings. If you go from Creston to Salmo, you will miss the Kootenay Lake ferry. If you have the time, I would suggest you go north from Creston along Kootenay Lake and take the ferry. This is a route that requires time, as it is quite winding and slow. You will end up coming off the ferry at Balfour, and then turn north to Kaslo. Again if you have time, a side trip into Nelson would be worthwhile. Kaslo has a decent town campsite if you want to spend time there. Also, there is a city campsite in Nelson, and a great Provincial Park and campsite at Kokanee Creek between Balfour and Nelson. Reservations recommended there from June 15 to Sept. From Kaslo to Nakusp is an easy drive. Great campsite at Summit Lake between New Denver and Nakusp. Choice of either a Provincial Park, or a full-service private campsite.
At Nakusp, the best choice is to continue north along the Arrow Lakes to Galena Bay for the second ferry crossing, then north to the Trans Canada at Revelstoke. Another alternative at Nakusp is to go south a bit along Arrow Lake and cross at Needles and then into Vernon in the Okanagan Valley. Then continue north until you link up with the Trans Canada highway. The rest of the route to Prince George is pretty straight-forward. The Trans Canada can be very busy at times.
A second choice that is also very scenic is to go through Kootenay Park, Banff Park and Jasper then on to Prince George. Instead of going into Creston, head for Cranbrook, then north to Radium Hot Springs. From there go through Kootenay Park into Banff Park, then north through Banff Park and Jasper Park to Jasper townsite. From there you go west to Prince George.
