ok I should re-state that to 50% of the backcountry of the central wasatch. the area of the wasatch surrounding SLC and PC.
I'm also going to differ between backcountry and sidecountry because they are very different. sidecountry areas see much more traffic, so if adding a lift creates a new easier accessed sidecountry area, I consider that a lose of backcountry. I don't necessarily consider the experience of skiing rocky point or wolvy (sidecountry) the same as skiing the needle (backcountry) and i think this is fair.
let me show you.......
Canyons to Solitude: this knocks out bear trap fork, mill d north fork, usa bowl, etc...... that's all now sidecountry, but this will be skied even more than now because you don't have to hike out.
Snowbird mary ellen gulch expansion: obviously you lose mary ellen, not a super big deal as its difficult to get in there, but now that lift will probably make access super easy into white pine.
Now these two events will probably result in....
PCMR to brighton: loss of 10420, guardsman area.
Alta expands into grizzly (a sure bet regardless). bye bye chads.
solitude expands into silver fork and to the top of grizzly/fantasy ridge (probably a sure bet regardless). increasing ease of access into days fork and silver fork.
Alta also has shown interest in putting a lift up flagstaff. That would knock out emma ridge, days, cardiff, superior, monte cristo......
So that's a loss of bear trap, mill d north, usa bowl, 10420, guardsman, grizzly gulch, emma ridge, silver, days, cardiff forks, superior s. face, monte cristo south side, white pine, mary ellen gulch..... I'd estimate that's about 50% of the central wasatch. sure you'll still be able to walk up days/silver/cardiff from BCC but now you're competing with a lift and helicopters (remember that's a prime heli zone).
and before you tell me how awesome this will be, just remember that you can hike all these areas anywhere from 45 minutes to 3 hours as it currently is..... pretty amazing access already and these areas are already crowded with backcountry skiers and most of the land is PUBLIC, forest service land and serves as a protected watershed for a million+ people.