Avalanches at US Ski Resorts

Sad news from Idaho where 2 skiers were killed in an avalanche at Silver Mountain.  Media reports indicate that the avalanche occurred in in-bounds terrain that had been open for less than an hour (see this article from The Spokesman-Review). 

This is an unfortunate reminder that mitigation efforts reduce avalanche hazard at ski resorts, they do not completely eliminate it.  As discussed in my book Secrets of the Greatest Snow on Earth, on average slightly less than one avalanche fatality occurs per year in in-bounds terrain that has been opened by ski patrol at US ski areas.  Although this is much lower than the number of deaths in backcountry areas, it is not zero.  Avalanche mitigation and hazard assessment is inexact.  It is a human endeavor in an environment in which there is not complete knowledge. 

That being said, there is little doubt that snow-safety teams do great work.  Just check out the photo below of Alta after it was raked by avalanches in 1885.  Imagine living or skiing at Alta without their heroic efforts. 

Alta, UT on July 3, 1885.  Courtesy Utah State Historical Society.