As a winter storm blasted Lizard Head Pass with a fresh layer of fluffy snow, 52 backcountry enthusiasts gathered Dec. 14 in full outdoor gear to learn about avalanche awareness.
The free on-snow clinic is offered every year by Friends of the San Juans in non-avalanche terrain. The clinic provides basic instruction on risk mitigation, snowpack, slope angle, slope aspect, avalanche warning signs, safe travel routes, and avalanche transceiver, probe and shovel use.
“We keep it friendly, interactive and informative – not intimidating. We want to make sure everyone has a positive experience,” said instructor John Strand.
Groups of six, each with an instructor, headed into a vast meadow. Their mission: raise awareness and reduce accidents.
Last year, three backcountry skiers were killed in avalanches in the San Juans including on Red Mountain Pass, near Lizard Head Pass and on the outskirts of Telluride.
This year, avalanche danger in Southwest Colorado has increased after recent storms, according to the Colorado Avalanche Information Center.
On Friday, the San Juans south of Rico and Red Mountain Pass were rated at “high” avalanche danger, a four on a scale of one to five.
An avalanche watch was issued for Friday, meaning large avalanches were likely on slopes steeper than 30 degrees.
The class that met in mid-December prepared for similar conditions.
Basic avalanche awareness has three tiers: preparedness, observation skills and safe travel.
Preparedness is simply “know before you go”: Get the gear, get the training, get the forecast, get the picture and get out of harm’s way.
An important first step is regularly checking the Colorado Avalanche Information Center forecast, which provides detailed daily reports on all mountain ranges in the state. It also documents slides and accidents.
Depending on snow and weather conditions, CAIC rates the avalanche danger scale at low (1), moderate (2), considerable (3), high (4) and extreme (5). The forecast applies the danger ratings to below treeline, near treeline and above treeline.
“The CAIC website allows you to become your own historian on snowpack conditions as the season progresses,” said assistant instructor Heather Swallow. “Start watching it in October so you can follow trends.”
Observation takes practice, Strand said, but the payoff is a safer backcountry experience.
Warning signs to observeEvidence of previous avalanches.Cracks in the snow around your feet.A hollow-feeling snowpack underfoot.A “whumping” sound as you walk, which indicates that the snow is settling and a slab might release.Heavy snowfall or rain in the previous 24 hours.Significant warming or rapidly increasing temperatures.Surface patterns on the snow made by strong wind, which may indicate that snow has been transported and deposited in dangerous drifts that could release.Cornices of snow that accumulate along ridges. They can break off and cause avalanches and should be avoided.Safe travel in a dangerous placeAvalanches typically occur on slopes of 30 degrees and higher. Ninety percent of the time, they are triggered by skiers, snowshoers or snowmobilers.
“We have the power to choose where to go,” Strand said. “The most important skill is identifying slope.”
Orienting yourself to slope angle and directional aspect takes practice, but is essential. A basic inclinometer placed on a ski pole positioned on the fall line will tell the angle of a slope, and a compass will show which way it is facing. Stickers showing slope angles can be fastened on a ski pole to hold up for reference.
Also beware of terrain traps. For example, a ski tour or snowshoe trip in the bottom of a valley may seem reasonable, but steep slopes above could send avalanches to the valley floor. Deep gullies can also slough off snow.
Weak layer triggers slidesCommon slab avalanches happen when a heavy layer of snow forms on top of a weak one. If there is a trigger from a natural or human source, the weak layer cannot hold the snow load, and it releases downhill in an avalanche.
Weak layers are well documented by CAIC for each mountain range based on seasonal snow data and field reports.
During the clinic, participants dug a pit in the snow to analyze snowpack conditions and identify potential weak layers.
Tracing your hand along a cross section reveals dense layers and sugary layers. The surgary layer is the weak layer. If it is near the bottom of deep snowpack, there is a definite risk of an avalanche on a slope 30 degrees and higher, instructors said.
Winter backcountry users should think about the weather and how it affects snowpack strength, Strand said.
For example, weak layers form after sunshine creates a crust on recently fallen snow. When it snows again, that crust becomes the weak layer. Rain falling on snowpack also will create a weak layer when the next snowstorm hits.
Slope aspect also makes a difference in snowpack. For example, early season snowpack might melt away on sunny, south-facing slopes, but snow will remain on north-facing slopes. After a new snowfall, north-facing slopes will gain a weak, crusty layer, but south-facing slopes may not because the previous snow melted away.
The right gearHaving the right rescue gear and knowing how to use it is paramount to safety in the backcountry. Skiers, snowshoers and snowmobilers should carry an avalanche transmitter (beacon), probe and shovel. Battery checks on the transmitter should be performed before the outing.
The beacons have two settings, transmitting and receive. During backcountry travel, everyone is transmitting. If someone is buried in an avalanche, everyone switches to receive and follows the arrows to the victim’s transmitting beacon. Probe poles help locate the victim so that he or she can be shoveled out.
“Backcountry users should also know basic CPR,” Strand said. Once buried, there is a window of about 15-20 minutes for the victim to be reached, dug out and hopefully saved.
Safe travelDon’t go solo. During conditions when avalanches are less likely, carefully choosing a route up a slope is important.
Avoid climbing up the avalanche path directly. Use ridges or the trees. Do not linger in the avalanche run-out zone. When skiing down, go one at a time, and watch out for each other.
If there is a heightened risk for avalanches, or you are not comfortable skiing a slope, your backcountry adventure does not have to be canceled, Strand said.
“Just adjust your tour to areas of low-angle, wide-open terrain,” he said, such as meadows on Lizard Head Pass across the highway from the Cross Mountain trailhead.
Colorado is most dangerousAvalanche fatalities occur in Colorado more than anywhere else in the U.S., according to an article by The Summit Daily and reprinted in the Colorado Sun. It cites statistics from the CAIC annual report for the 2018-19 season.
The newspaper reports that since the 1950-51 season there have been 287 avalanche fatalities in Colorado. The second highest was Alaska with 158 fatalities. Utah has had 120 fatalities since that time.
Last winter’s snowfall was above average statewide, leading to 4,273 recorded slides, The Summit Daily reports. Across the state, 135 people got caught in avalanches and eight people were killed.