I think it probably matters on the criminal side in showing recklessness. Maybe not so much, or necessary, on the civil side assuming the statutory negligence holds.Do we know this as a fact? And in the legal sense, does it matter?
As for knowing it for a fact, no not for certain. But there is good reason to believe someone from the Forest Service would testify there is no legal access from the ski area to this slope because of not just the avalanche danger to someone on the slope but also to those on the busy trail below. There are also decades of meetings where discussion on where to place the backcountry access gates took place.
Here's a good article with background on opening the backcountry gates:
https://www.telluridenews.com/the_watch/news/article_422633a3-1285-5a75-9465-b78747ffb1e9.html
And another article with more context that mentions this slope and has a quote from the Forest Service supervisor:
Still, it is not uncommon to see tracks leading down Telluride’s steep, deep and permanently closed Tempter Chute, where several skiers have died in avalanches over the years.
“One of the most important things we try to tell skiers is to not cut ropes,” says U.S. Forest Service ranger Scott Spielman, who supervises the Telluride ski area. “There is so much avalanche-prone terrain in the backcountry surrounding the ski area. The ropes are there for a very good reason.”
Most ski resorts engulfed by public lands require that all egress from the ski area be done through established backcountry gates. Leaving through a roped boundary carries the same penalty under the state’s Ski Safety Act as cutting an internal rope that isolates either permanently closed sections or areas where the slope isn’t ready for skiers. But skiers who leave the boundary are rarely pursued by patrollers. Those who cut ropes inside the ski area tend to be easily spotted and captured.
https://www.denverpost.com/2009/01/19/crossing-the-line-youll-pay-for-it/
“One of the most important things we try to tell skiers is to not cut ropes,” says U.S. Forest Service ranger Scott Spielman, who supervises the Telluride ski area. “There is so much avalanche-prone terrain in the backcountry surrounding the ski area. The ropes are there for a very good reason.”
Most ski resorts engulfed by public lands require that all egress from the ski area be done through established backcountry gates. Leaving through a roped boundary carries the same penalty under the state’s Ski Safety Act as cutting an internal rope that isolates either permanently closed sections or areas where the slope isn’t ready for skiers. But skiers who leave the boundary are rarely pursued by patrollers. Those who cut ropes inside the ski area tend to be easily spotted and captured.
https://www.denverpost.com/2009/01/19/crossing-the-line-youll-pay-for-it/