Crossing Glaciated Passes: When a Day Hike Becomes Real Mountaineering

Many of the popular treks around the world include sections of glaciated terrain on the typical day of hiking. The well known Tour du Mont Blanc has several passes with significant amounts of glacier on them. There are also numerous trails through the Karakoram, that cross over glacier tongues and outcrotch valleys. And within the Andes there are many routes that cross over sections of permanent ice. It appears to be completely manageable in sections, within a normal day of trekking. However the consequences of getting it wrong within this type of terrain are extreme.

The vast majority of hikers under estimate the time to cross a glaciated pass. Typically the hike is broken down into 6hr of walking with the 90 minutes or so of ice in the middle. We all need to double check that section.

What makes a glaciated pass so different from hiking a snow-free trail.

The differences from snow-free hiking:

Crevasses, hidden under snow bridges, can be invisible. The footing is unpredictable. At times the trekkers are walking on soft snow on top of very hard ice below. This is a recipe for ski type slides. You do your best to control your downward motion but often end up in a mini avalanche. A relatively shallow grade of 25 degrees can develop into an 200 meter long slide when walking on snow over a hard surface of ice. Rockfall and Icefall: A serious hazard to travelers crossing many of the passes between glaciers. Weather affects the glaiced section differently than the rest of the trail. It could be very hard early in the morning after a snowfall, and then get very sloppy in the middle of the day after the sun hits it. The same slope at noon can be very different than at 6 am.

The kit required

Even on standard trekking routes with sections of glaciated terrain, you would typically need special gear for that section.

Crampons or microspikes for the slope of the ice. As a rule of thumb, microspikes are usually fine for very short sections of low-angled ice, but full crampons are needed for anything else. An ice axe to be used as a third leg whilst walking and for self-arrest should you fall. A helmet for sections with rockfall risk above. A harness and rope for sections of serious crevasse risk. Roped travel is the only way to survive a crevasse fall. Sun protection. Glaciated surfaces reflect significant UV.

However, many hikers crossing glaciated passes are not adequately equipped for a number of reasons resulting in a high incident rate on these sections of route.

The decision: when to turn around

When not to cross: The rules: The thing I learned the hard way:

Freshly fallen snow on the route or across bridges fills in crevasses, and covers other hazards such as exposed rock or running water. Such surfaces will not have had time to set hard by the following day. Afternoon thunderstorms: Cross early or don’t cross at all. Snow that is soft enough to sink down into past the knees while walking on it creates huge problems crossing glacier terrain. As you go, you could create huge holes in the surface of the glacier. Chances are that there will be no corresponding slots to create a tunnel and collapse, but the biggest danger would be to unwittingly posthole through a weak section of a snow bridge spanning a large crevasse. Traveling solo on a glacier that requires the use of a rope for parts of the crossing and that could cause severe injury or death in the event of a fall for a non-mountaineer hiker. When hiking, it is best to evaluate your ability to reach your destination by evening. If you have been hiking for an hour longer than expected when you hit the glaciated section of the pass, you should consider turning around. Even though you can probably make it to camp in the dark, the arduous hike in the dark is often worse than turning around for the night.

The timing rule

For assessing day-to-day risk on glaciated passes, the most important variable is time of day. When the pass is frozen hard in the morning is generally safest. In the late morning through midday, as the surface softs, the condition of the snow bridges starts to degrade, and the risk of falling debris increases dramatically.

Get off the glaciated section by 11 am in summer; generally, start from the highest camp to tackle the snow-covered section the morning after. This will allow you to tackle the pass in the early morning hours when the snow is frozen hard.

The guided option

For most trekkers without mountaineering training, a guide for the glaciated section is the right answer. The guide offers:

Roped travel technique. The guide will be familiar with specific sections of the route and let you know about crevasses (big holes in the snow bridged by metal/cable etc.) and the general state of the snow. Crevasse rescue capability if something goes wrong. Makes decisions about whether you can complete the crossing on a given day.

Even on the popular routes for trekking with glaciated passes a guide for the actually glacier crossing can be booked for half a day. Their fee is between 150 $ and 300 $ per person and that is really cheap when comparing it to an emergency evacuation which costs up to several 1,000 $.

The popular routes with glaciated passes

Examples of popular treks which involve actual glacier crossings:

The Tour du Mont Blanc (Col de la Croix du Bonhomme variations). The Walker Haute Route from Chamonix to Zermatt (multiple crossings). Trekking routes in the Karakoram (Concordia, Snow Lake). Some Cordillera Blanca trekking routes in Peru. There are many high alpine routes in New Zealand’s Southern Alps.

When planning a trek that crosses a glaciated pass, research the route, and specifically review the trip reports of other hikers that completed the same trek during the same season. Glaciers are retreating all over the world and weather patterns can also change from year to year affecting the amount of snow at the time you arrive. As a matter of course, I arrive at the airport the day before my scheduled departure. On two occasions, this proved to be a very good thing, as both flights were delayed resulting in missed connections had I arrived on the same day as my scheduled departure.

What goes wrong, when it goes wrong

The accident patterns on glaciated trekking passes:

Slipping on hard ice while wearing hiking boots without crampons and sliding down into a side moraine or into a crevasse. Falling into a hidden crevasse alone and having no rescuers to retrieve you from the crevasse. Being caught in an afternoon thunderstorm while trekking above tree line. Running behind schedule and ending up on the pass too late in the day, having to cross it in the failing light. Hypothermia due to the trekkers not being dressed adequately for the temperature drop.

None of these are unusual or ‘exotic’ risks that are encountered on mountains. They are a compilation of typical accidents that have occurred on many of the most popular glaciated trekking passes over many years.

The honest framing

So we cross one pass – on a trek after all – and it is real mountaineering. For ninety minutes in the midst of a long day of walking the difference between a successful crossing and a serious accident is often down to one factor: preparation. For the glacier section of your trek prepare specifically for that section. Take a one-day course in glacier travel the day before you depart. Hire a guide for the pass crossing. Take the necessary gear. Set off early. Cross high and in good time to return in good light. Cross high and in good time to move deliberately and carefully down the other side. Then the crossing will be the highlight of your day, not the source of fear.

Whether you are planning a short hike or a long trek with sections of glaciated terrain, prepare for the section of glaciated terrain on your trek as you would for a short mountaineering climb. Consider taking a 1-day Glacier Travel course before your trek. Hire a guide to lead you across the glaciated pass. Wear appropriate hiking boots and carry the necessary glacier travel gear such as crampons, ice axe, harness and ropes. Start early in the day and cross the pass in good light. Travel deliberately and do not rush.