Surfing the web, I stumbled upon a story about Snowbird planning to trade land across the canyon for access into Mary Ellen Gulch, which is roughly south of Mineral Basin. The access is supposed to come via tram from Hidden Peak to West Twin. The exit is supposed to be via lift into Mineral Basin.
If they take it right down to the bottom of the gulch (7500ft), it'll be close to 4000ft vertical (albeit south facing). As well, it'll have plenty of beginner/intermediate terrain, as the overall slope is pretty low angle... finally we can take our wives and kids there. Should be interesting to see how it shakes down. Personally, I like the plan, especially if they build a lift (or lifts) as per my Google Earth shots below... though I could see how the backcountry folks would oppose it. Hopefully the "land trade" factor would win them over.