The avalanche reached half a mile in width, pouring 65,000 tons of snow in a section of the Alpine Meadows ski resort in California. By the time it was over, the 10-foot deep avalanche had killed seven people and caused more than $2 million in property damage.

It was the worst ski-area avalanche in U.S. history. However, thanks to the efforts of avalanche dogs, one person miraculously survived after more than a day buried in snow. It was a miracle because, on average, the chances for a live recovery fall to just 30 percent after 35 minutes buried in snow. In an avalanche, time is of the essence because the threat of asphyxiation and exposure increase exponentially with each passing minute.

But avalanche dogs greatly increase those odds of survival. A single well-trained avalanche dog can efficiently scour 2.47 acres in 30 minutes. By comparison, 20 people require 4 hours to cover the same area. Like rescue and bomb-sniffing dogs in other situations, these canines are masters of their trade, able to be airlifted with their handlers within minutes of a reported avalanche.

Dangers of Avalanches

In the avalanche business, there's a grisly saying: "All the avalanche experts are dead" – a testament to the fact that few people who experience an avalanche live to tell about it. Avalanches are serious threats that claim lives every year. The risk of an avalanche usually begins with the degree of slope – the dangers of a slide generally begin at 30 degrees, but they have started on slopes of 25 degrees. It is important to know the slope of an area. People often do not check to see if an area has experienced an avalanche – a sign that the slope is stressed from the weight of snow and the angle.

They also do not heed the warning of an impending avalanche: if snow collapses beneath you or sends cracks shooting ahead, you may be in danger. Heavy snowfall of one inch an hour or strong winds blowing snow and snow plumes off ridges are also risk factors. When they get the call, dogs and handlers work against the weather and the clock.

Saving avalanche victims is only part of the job of these dogs, however. When hikers get lost, exhausted or caught in a storm, they sometimes retreat to a snow cave to await rescue. Avalanche dogs are used to find these people who are at risk of injury or death by exposure. Younger and older people sometimes become injured and are covered by snow, making them impossible to find by the human eye. Again, the dogs' sense of smell comes to the rescue.

Training an Avalanche Canine

Avalanche dogs were first trained by the Swiss Army in the 1930s. An avalanche dog possesses the same attributes that search and rescue, bomb-sniffing and arson dogs do: namely, a superior sense of smell, the desire to please and the intelligence to stay focused on the job.

Avalanche dogs seek pools of human scent that waft up from the snow. If a dog catches a scent, he buries his head in the snow to find a stronger scent. If the scent gets stronger, he begins to dig to get to the source. If it gets weaker, he works outward to find a stronger scent.

To the dog, the search is a game, one he is determined to succeed in. Training is geared towards the dog's desire to play. Initially, the handler teaches the dog to find something the dog really enjoys under the snow. The game at this point is very easy to build the dog's confidence. He is given plenty of time to search for the object, which is buried only a few inches under snow.

The dog is trained to find objects progressively deeper and farther out, in shorter periods of time. Distractions are added. These include equipment, people, food and the smell of urine. As the dog learns to ignore distractions, objects – including people – are "buried" even deeper, in denser snow. More distractions are added, and the dog must also learn to contend with the wind, different weather conditions and a shorter time limit. The intense training has enabled some dogs to pull off prodigious feats of detection. Dogs have reportedly found victims buried as deep as 40 feet in Switzerland and 33 feet in the United States.

The dog and the handler also learn how to enter and exit helicopters as well as chairlift evacuations. Dogs and handlers drill constantly to be ready to respond when an avalanche occurs. If they can locate a person within the first 15 minutes of burial, the victim has a 90 percent chance of recovery.