Skiing and snowmobiling are becoming increasingly popular in Alaska’s limitless backcountry. Unfortunately, many winter outdoor enthusiasts fail to take necessary precautions before heading out. Given the heavy snowfalls that occur, the steep slopes the snow piles up on, and the high winds that accompany many storms, it should come as no surprise that avalanches are a real danger in Alaska.

Nearly all avalanches are triggered by the victims. This is particularly true for snowmobilers, who often attempt such dangerous practices as “high-marking” — riding as high as they can up steep slopes — and are killed in avalanches that result.

If you really want to avoid avalanches, ski only on groomed trails or “bombproof” slopes that, because of aspect, shape, and slope angle, never seem to slide. Unfortunately, this isn’t always possible, so backcountry skiers and snowmobilers need to understand the conditions that lead to avalanches.

The best way to learn is from a class such as the avalanche safety programs taught by the Alaska Avalanche School (907/345-0878, www.alaskaavalanche.com) in Anchorage, or Juneau’s Southeast Alaska Avalanche Center (907/586-5699, www.avalanche.org/~seaac). Learn more at www.avalanche.org, including information on avalanches and course offerings around the nation.

Heading Out

An avalanche safety course is extremely valuable, but you can also help protect yourself by following these precautions when you head into the backcountry:

Before leaving, get up-to-date avalanche information. The Chugach National Forest Avalanche Information Center (907/754-2346, www.cnfaic.org) has current snow conditions for the Kenai Peninsula; it’s updated several times a week in the winter.

• Be sure to carry extra warm clothes, water, high-energy snacks, a cell phone, a dual-frequency avalanche transceiver (make sure it’s turned on and that you know how to use it), a lightweight snow shovel (for digging snow pits or emergency snow shelters, or for excavating avalanche victims), first-aid supplies, a Leatherman knife, a topographic map, an extra plastic ski tip, a flashlight, matches, and a compass. Many skiers also carry that cure-all, duct tape, wrapped around a ski pole. Let someone know exactly where you are going and when you expect to return. It’s also a wise idea to carry special ski poles that extend into probes in case of an avalanche.

• Check the angle of an area before you ski through it; slopes of 30–45 degrees are the most dangerous, while lesser slopes do not slide as frequently.

• Watch the weather; winds over 15 mph can pile snow much more deeply on lee slopes, causing dangerous loading on the snowpack. Especially avoid skiing on or below cornices.

• Avoid skiing on the leeward side (the side facing into the wind) of ridges, where snow loading can be greatest.

• Be aware of gullies and bowls; they’re more likely to slip than flat open slopes or ridgetops. Stay out of gullies at the bottom of wide bowls; these are natural avalanche chutes.

• Look out for cracks in the snow, and listen for hollow snow underfoot. These are strong signs of dangerous conditions.

• Look at the trees. Smaller trees may indicate that avalanches rip through an area frequently, knocking over the larger trees. Avalanches can also run through forested areas, however.

• Know how much new snow has fallen recently. Heavy new snow over older, weak snow layers is a sure sign of extreme danger on potential avalanche slopes. Most avalanches slip during or immediately after a storm.

• Learn how to dig a snow pit and how to read the various snow layers. Particularly important are the very weak layers of depth hoar or surface hoar that have been buried under heavy new snow.