Hate to say it, but this decision sounds relatively reasonable. Granted you're losing the evening skiing opportunity, but it's a classic case of a couple of idiots ruining it for everyone. In our litigious society, I can't blame WMR or the USFS:
This season, resort staff have reported several near-miss incidents with winch cats [...] [recently] a grooming operator watched an after-hours hiker ski beneath his winch cable, encountering aggressive resistance when the skier was asked to vacate the area for his safety...
"Our grooming operators are constantly worried that they're going to inadvertently injure or kill someone who makes a bad decision out there..."
Sounds like someone's going to lose their head, literally.
The policy [...] will restrict uphill traffic [...] to a single route on the mountain, as well as limiting the hours[...]. Uphill traffic will be allowed on the route during ski season from 6:30 a.m. until the resort closes... [and] between 8:00 a.m. and 5:00 p.m. for the first 14 days after ski season ends, with no active restrictions outside those hours and dates.
This policy is a heck of a lot better then other policies I'm aware of, including Bridger Bowl's which prohibits all uphill traffic
all the time within the ski area boundary. I'd kill to have a designated route at Bridger for early morning runs (or even mid-morning), but that will probably never happen. So, IMO, enjoy what you have, it could be a lot worse.
[And yes, I understand the argument against restricting human-powered public activities on public land, but there's plenty of precedent for this when the common public good it at stake (municipal water supplies, temporary fire closures, wildlife area closures)]