Avalanches occurs when the stress trying to pull the snow downhill exceeds the strengthof the snow cover. There are three things involved in an avalanche — a steep slope, weak snow cover and something to trigger it. Most avalanches occur just after large snowstorms — more than 80 percent — in February, March and January. Some are caused by thaw in April. Most avalanches occur in the backcountry, outside of developed ski areas.
Large avalanches are most likely to happen in obvious paths, such as bowls, gullys and above timberline. Look for signs of avalanches in the past, like bent or damaged trees.
You cannot entirely eliminate risk if you travel in avalanche terrain, but you can minimize risk by using good technique, such as: climb, descend, or cross avalanche areas one at a time; cross a slope at the very top or bottom if possible; climb or descend the edge of a slope rather than the center; carry and know how to use avalanche rescue gear; and turn back or alter your route if you detect signs of unstable snow.
When the snow cover is very unstable, nature often broadcasts clear danger signals. Fresh avalanches are the best clue. Snow that cracks, collapses, or makes hollow sounds is also unstable. Weak layers that are found by digging snow pits are signs of unstable snow. Snow that has become wet from thaw or rain can be dangerous.
You always should have an avalanche transceiver (or beacon), shovel and a collapsible or ski pole probe. You should practice frequently to be proficient in using your beacon.
Surviving avalanches can depend on luck; therefore, it is always better to avoid them in the first place. Remember that only 1 of 3 victims buried without a beacon survives. If you are caught, first try to escape to the side, or grab a tree or rock. If you are knocked down, get rid of your poles, skis, and a heavy pack. Swim with the avalanche to try to stay on top and avoid trees. When the avalanche slows down, reach the surface or make an airpocket.
Colorado Avalanche Hotlines
If you are not near the Internet, our daily hotline reports on mountain weather, snow and avalanche information are updated each morning via telephone.
Denver/Boulder — statewide (303) 275-5360
Fort Collins — statewide (970) 482-0457
Colorado Springs — statewide (719) 520-0020
Summit County — and surrounding areas (970) 668-0600
Durango — southern mountains (970) 247-8187
Aspen — local (970) 920-1664
Vail — local (970) 479-4652
Yet another incident involving a semi-tractor trailer losing it on the snow-slick roads in Glenwood Canyon has both the westbound and eastbound lanes of Interstate 70 closed east of Glenwood Springs as of 11:15 a.m. Monday.