If you're coming from the south (Crowsnest Highway) start in Kaslo:Drive about 90 km north from Creston on the 3A (also an amazing ride) to the Balfour Ferry. Take the free crossing, and drive another 35 km on the 31 to Kaslo. Hwy 31A starts towards the north end of town.
If you're coming from the North (Trans Canada Highway) start in New Denver:
Follow Hwy 23 and the signs for the ferry south about 50 km from Revelstoke. Take the free ferry crossing and continue another 50 km on the 23 to Nakusp. Follow signs for Nelson/Castlegar to go west on Hwy 6. Continue 45 km to New Denver. Hwy 31A has signs for Kalso and Sandon.
This road is extremely twisty, through gorgeous untouched wilderness. You're mostly surrounded by forest, and will ride alongside a raging little creek (I don't think it is a named body of water, but it was really flowing when we came through), the stunning Bear Lake and Fish Lake, as well as a couple of other small bodies of water. You'll cross several quaint wooden bridges, which were in good repair. We didn't see a single man made structure other than the road.
Non-stop twists and turns and yellow signs telling you to slow down for the upcoming corners. Visibility is very good through many of the corners so if you are so inclined to consider those signs a suggestion you can do so safely in many cases. The road surface was typical of a secondary highway in B.C. - which is to say very good, but you never know what you might come across on these less traveled roads. We didn't encounter any major heaves, potholes or broken sections of pavement but this will change year to year. It appears that they maintain the road quite well though. Several wooden bridges as you exit corners can be slippery if it is wet, so be extra cautious and keep your eyes peeled for those. Traffic was non-existent. Literally, we did not encounter another car going in our direction, despite several stops for pictures, and saw only 2 vehicles heading the other way. This was on the Saturday of a long weekend. The road is mostly flat.
There is almost nothing at all on this road. There are a few campgrounds, but we didn't take advantage of any of those. You can detour 6 km to Sandon to see an extremely well preserved ghost town. We didn't have the chance so I can't comment on that. But Kalso and New Denver will have all the services you need.