There are a few rural roads that don't get plowed. They have big "Enter at your own risk" signs, often in the best of conditions you need 4 wheel drive (all wheel drive will work, but if you don't understand the difference don't attempt it) to get through them at best.

The vast majority of rural roads get plowed. Everyone who lives in a rural area has at least one plowed route from their driveway to the rest of the world.