Avalanches are a fact of life. Given the realities of snowfall and slope angles in the mountains, there is no way to prevent them from occurring. Nonetheless, major avalanche catastrophes provoke outrage among the public, who demand that the government and private enterprises take steps to protect them. These demands are somewhat unrealistic, however, since the vast majority of avalanche fatalities in the United States and Canada take place in the backcountry, far from population centers or transportation routes, where no avalanche control is available.

Public officials and resort owners in many mountainous regions have gone to great lengths to minimize the damage that these inevitable snowslides can cause. Austria, a mountainous country in the Alps, has spent more than $700 million since 1945 on avalanche disaster prevention.

Three basic strategies are used to protect the public from sliding snow: active defusing of dangerous slopes, passive...