If you want to farm this achievement quick, what I did was take the drone (press up on the d-pad to use) and fly it straight up in the air and focus on "?" by the smoke and the drone will scan the location and unlock it on your map. Open the map and fast travel to the Bivouacs you scan and rinse and repeat with the drone. I was able to get across the entire map and all the providence's without ever having to take a vehicle or run/walk.