If any of the skiing youth of the world vying for Olympic titles at Squaw Valley next month lift their eyes from slopes and trails as they hurtle downward, they might be thoroughly startled to find themselves staring at assorted pieces of World War II artillery placed here and there on mountainsides and ridges. No less than four recoilless rifles (three 75-millimeter guns and one 105-millimeter) will be strategically scattered around the area, with sights zeroed in.
Their targets, however, will not be skiers, skaters or spectators but the slopes which, heavily weighted by new-fallen snow, show signs of avalanching. The danger of avalanches at Squaw Valley is a very real one, as it is at almost any of the winter resorts in the Rockies and Sierras. Guarding against it will be a small' army of dedicated men whose deeds are fast becoming a part of mountain legend—the Snow Rangers. For the past year a group of these avalanche experts of the U.S. Forest Service has been studying the slopes and runs and taking measures to make sure that avalanches will not disrupt the VIII Olympic Winter Games.
A Snow Ranger has the power to put any of his area's slopes out of business by simply posting a sign saying, "CLOSED, AVALANCHE DANGER." Such a sign could stop the Olympics indefinitely if the Snow Rangers thought it necessary.
It is a big job and often a perilous one. Every slope steeper than 25�, on the average, can avalanche occasionally. Every slope pitched at more than 35� will avalanche frequently. The steeper the slope the greater the possibility that gravity will overcome the cohesion of the snow or its adhesion to the ground and send it roaring down a mountain at speeds as high as 100 mph.
Avalanches can, and have, wiped out whole communities. The most notorious example in the U.S. was a series of slides that knocked out the town of Alta, Utah in 1874, killing more than 60 people. Fittingly, it was at the ski resort of Alta, near the ruins of the town, that the U.S. Forest Service started its avalanche control program 19 years ago.
Alta was one of the first resorts in the prime avalanche region. The ski area opened with a promise from the Forest Service that it would send men to study the situation and keep skiers off the slopes that looked dangerous. At that time Forest Service personnel knew very little about avalanches. They played it safe and for much of the season kept skiers off the most attractive, wide-open runs. Since some of the closed slopes never did avalanche, a great deal of irritation developed. Safety, however, was the Foresters' predominant aim, and for the first few winters they spent their time at Alta systematically studying temperature, rate of snowfall, snow types, moisture in the snow, effect of wind on the snow and the relationship of these factors to actual avalanche occurrence. After a couple of years they were able to predict with rough accuracy the likelihood of avalanche for a given set of conditions. But the need for more accuracy and some method of control became acute.
Clearly the problem demanded a team of specialists, and in 1945 F. C. Koziol, supervisor of the national forest in which Alta is located, started organizing one. His first need was a man who would be 50% scientist, 50% skiing mountaineer and 100% interested in making avalanche control his life's work. Koziol found such a man in Harvard Graduate Monty Atwater, a 200-pound bear of a fellow who had, among other things, run traplines in Montana on skis and trained the top mountaineers of the 10th Mountain Division for the Italian campaign of World War II.
Atwater boned up on avalanche statistics and snow-pack formation and soon was put in charge of the studies at Alta. He thus became the first year-round Snow Ranger. From then on, the techniques of forecasting improved considerably, and Atwater started solving the problems of control. He decided that it was useless to attempt to build expensive walls or ditches to divert the slides. The only real solution was to get up on a slope that looked ready to go, clear everyone out below and make it avalanche then and there.
Atwater's first attempts to precipitate avalanches were crude. They also demanded a high degree of courage: he and his men would get up on an overhanging snow cliff, known as a cornice, and kick it loose, sending it tumbling to the slope below. If the lower slope avalanched, then it was safe until the next storm. If it did not, it was safe anyway.
If no cornice was handy Atwater and his men found that they could accomplish the same thing by skiing the fracture line of a slope. This is the line where the snow mass breaks off if and when it starts to come down. The weight of a skier on this critical line will usually avalanche a slope that is potentially dangerous.