This might just be a regional thing. In the Pacific NW where I was skiing ~100 days/year in my teens and early 20s in the 90s, "Backcountry" was the term used

This might just be a regional thing. In the Pacific NW where I was skiing ~100 days/year in my teens and early 20s in the 90s, "Backcountry" was the term used to describe any skiing out of ski area boundaries. Touring or Randonee, where you skin uphill and then lock your heels to ski down, inbounds or out of bounds, were called Randonee and weren't particularly associated with the term Backcountry at all except that is typically where you would go to do Randonee.