La Julie has some comment on the legals in Switzerland:-
http://www.tdg.ch/actu/sports/piste-legal-condamnable-cas-avalanche-2010-01-04
Swiss legislation is sufficient to punish a skier triggered avalanche outside the marked runs. But “We can not stop a ‘freerider’ from skiing outside secured ski pistes” according to the ATS counsel Valais Pierre-Andre Veuthey, who is familiar with the problem. But the crime of obstructing public traffic may be applicable when a skier crosses a net or a rope that indicates a danger zone.
Switzerland does not have legislation that allows a person to be fined or cautioned when they leave a marked trail. The off-piste is a public area too. Nothing prevents anyone from moving on the public domain.
The triggering of an avalanche can result in a sentence, even when there are no victims from the slide. Having created a danger may be sufficient and courts are now more sensitive than in the past, says Veuthey.
No police
If there is a risk it would require a police presence on the ski slopes to report offenders and this is not being enisaged even by ski lift operators, said Eric Balet, director Téléverbier.
The lifts are responsible for securing marked trails whether groomed or not. “We can not forbid people to go off piste,” explains Mr. Balet. Leaving the ski runs implies leaving the ski area. The lifts can only warn and put ropes or nets.
Neighbors more severe
Crossing such a rope can be merit a fine, but only in Italy or France. Police officers patrol the trails and verbalize dangerous behavior. Speeding and off piste skiing risk fines, according to Nicolas Perretta, president domain Courmayeur - Mont Blanc (I).
The skiing off-piste is subject to municipal bye-laws. The municipal authorities may forbid if there is an avalanche danger. And the police presence on the ski runs has a deterrent effect on users.
The police presence has become common in many ski areas. But the police only patrol in ski areas where they have been invited, says Perretta. Overall collaboration with the police is positive.
-- note bye-laws restricting off piste skiing are very rare in France. In les Arcs, Courchevel and Vallorcine there are restrictions on entering nature reserves and other mayors may restrict off piste skiing when the avalanche risk is Considerable or higher.