Winter Hike Into the Morteratsch Glacier Caves

Into the Blue: a Winter Hike Into the Morteratsch Glacier Caves

High in the Engadin valley, winter casts a glittering shroud over the dramatic peaks of the Bernina Range. While most visitors stick to the manicured ski slopes of St. Moritz or the gentle, groomed winter paths of the valley floors, a thrilling challenge sits waiting at the end of one valley…

Deep within the Morteratsch Glacier - the longest glacier in the Engadin - the massive torrents of summer meltwater leave behind a fleeting winter landscape: subglacial tunnels sculpted into the ancient, compressed ice. Accessible only during the sub-zero months, entering these shimmering blue vaults requires a bit of courage…

This winter hiking/snowshoeing itinerary breaks away from the crowds. You will trek from the Morteratsch train station, strike off-trail to scale the exposed, unstable glacial front to explore the most accessible caves, then return via a beautiful snowshoe route along the riverbed, and finish off with a panoramic valley walk to wrap up the journey at the ski resort of Pontresina.

Route Overview & Technical Profile

This point-to-point journey transitions from a groomed winter approach to technical alpine environment, drops into an off-trail riverbed snowshoe trek, and finishes with a scenic valley floor winter walk.

• Distance: ~14.0 Km (8.7 miles) total (c.22+ km + optional extensions):

• Glacier part: ~8.5 km circuit (Morteratsch Station to Glacier Caves and back via the river snowshoe trail)

• Engadin Valley part: ~5.5 km (Morteratsch to Pontresina Train Station)

• Elevation: +250 meters (820 feet) ascent on the glacier / -120 meters gentle net descent along the valley

• Duration: 5 to 6.5 hours (or more with extensions & exploring) 

• Difficulty: WT3/WT4 Winter Trekking for the glacier section; Easy groomed winter walking for the valley extension

• Glacier Specs: The glacier holds roughly 1.2 cubic km of ice, tapering down to a depth of 75 m near its snout, and currently loses a staggering 30-40 m of length every year due to warming summer heatwaves.

Expedition: Step-by-Step

Step 1: The Groomed Approach & The Accelerating Glacier Retreat

The journey begins at the Morteratsch Railway Station (1,896m), an iconic stop on the UNESCO-listed Bernina Express railway line. Strap your snowshoes & crampons to your pack, cross the tracks by the station inn, and step onto the groomed winter walking track (SchweizMobil Route 314).

This initial 3.5-km leg serves as a scenic warm-up, weaving through frost-coated larch forests along the valley floor. Lining the trail are 16 chronological steles marking exactly where the glacier's tongue once stood in years gone by. Walking past these markers provides a striking visual lesson on how rapidly the ice is disappearing…

Step 2: Going Off-Route into the Glacial Caves

The groomed trail ends at the official observation area. To reach the ice, you must step past the safety markers, cross the river bridge, and leave civilization behind for a little while…

The terrain immediately turns hostile. You are now navigating an alpine forefield choked with snow-covered moraine boulders and rubble. Trekking poles are essential here to probe the snowpack, as fresh drifts frequently hide deep, leg-breaking voids between the rocks (some with freezing, running water underneath). Push a kilometer or so +100m out beyond the viewpoint (on the left), angling toward the exposed flank of the glacier tongue.

Step 3: Early Morning Ascent into the Sapphire Caves

As the rock and snow give way to hard, wind-scoured ice, find a stable platform to drop your pack and gear up. Fasten on your climbing helmet, your crampons or micro-spikes onto your mountaineering boots & draw your trekking poles or ice axe. 

Note: The glacier has currently retreated onto a steep 60-to-70-meter bedrock cliff (Felsstufe). This creates a highly dynamic and unstable environment - as you approach the arched cave openings, you may notice fractured or shattered rock debris lying inside or flanking the tunnel mouths (or even in the icy roof). 

Critical Timing Strategy: 

You should ideally time your arrival at this hazard zone for the early morning hours. The severe cold of the night acts as a natural glue, freezing the structural ice vaults and the loose, fractured rocks securely in place. As the sun rises and solar radiation hits the valley walls later in the day, the thermal shift drastically increases the risk of sudden rockfalls and/or cave-ins. 

Switch on your headlamp (if necessary) and step beneath the frozen roof. The interior is a breathtaking warren of compressed, ancient ice. The scalloped walls glow with an intense, translucent sapphire blue. The silence inside is heavy, broken only by the sharp metallic scrape of your crampons and the occasional, deep structural groans of the glacier shifting under its own weight. 

Step 4: Breaking Trail by the River Route

Because glacier caves trap dense, freezing air, hypothermia can set in quickly. After viewing the ice formations, carefully descend the -100m ice flank, clear the snowy boulder field, and return back to the vicinity of the river bridge near the main viewpoint and safety.

Instead of rejoining the high, groomed walking track for the return trip with the tourists, strap on your snowshoes. The descent follows an alternative, backcountry route that closely hugs the low banks of the Ova da Morteratsch river. 

This return path is pure winter isolation. As you plunge through deep, unbroken powder close to the rushing, half-frozen water, you bypass most of the educational signs. The river route keeps you deep in the trough of the valley, surrounded by silent, snow-heavy pine forests with the massive faces of Piz Bernina & Piz Palu at your back. Follow the natural contours of the riverbed as it winds its way all the way back to the railway station…

Step 5: Refueling and Resuming the Trek via the Forest Waypoints

Back at the Morteratsch Train Station, pack away your mountaineering gear and step inside the restaurant at Hotel Morteratsch for a refueling snack. Once fully recharged, pack your snowshoes away and step onto the beautifully groomed, wide winter hiking trail heading north out of the valley toward Pontresina…

While the spectacular side gorges of the Bernina waterfalls may be too slippery and dangerous to navigate in the snow, the main groomed forest path features fantastic, winter-safe points of interest:

• UNESCO World Heritage Railway Loop: The path winds directly alongside the tracks of the Rhaetian Railway (RhB) Bernina Line. Because these red trains master the intense valley grades entirely without cogwheels, you get a front-row seat to world-class engineering marvels against a snowy forest backdrop.

• Grand Tour Lookout at Plauns: Midway through the forest, the trail opens into a snowy clearing where the official Grand Tour of Switzerland Photo Spot frames a perfect window of the trains moving past the soaring massifs of the Bernina glaciers.

• Chamin Medieval Tower Ruin: As the trail draws closer to Pontresina, you pass beneath the Torre Chamin. This striking 13th-century stone tower stands hidden in snow-dusted pines, serving as a historic monument to the ancient alpine pack-horse trade routes that crossed the Bernina Pass long before modern trains existed.

After roughly 5.5 km of relaxed, steady downward cruising through these landmarks, you will arrive directly at the bustling Pontresina Train Station, the perfect logical end for your day.

Bonus Challenges for High-Energy Trekkers

If your legs still feel invincible after a grueling morning in and around the glacier and you have plenty of winter daylight left, the surrounding trail networks offer unique ways to extend your expedition:

1. The Ultimate Wild Detour: Into the Val Roseg (+6 to 8 km)

If you accidentally miss the main turn-off into Pontresina (like I did) or actively seek out a quiet, snow-bound wilderness challenge, you can turn left onto the trail heading deep into the Val Roseg. This track drops you onto a spectacular, car-free valley floor flanked by ancient forests and soaring peaks. 

Pushing a few kilometers up this valley alongside the frozen Roseg river adds a massive layer of untamed winter beauty to the day, though it will instantly push your total trip distance over 20 km. Keep a sharp eye on your map at the intersections unless you want to find yourself trekking all the way to the Roseg Gletscher hotel!

2. The Plain Extensions: Cruising the Valley Floor

For those who want extra distance without the wild elevation or deep forest navigation of the Val Roseg, the groomed plain trail connects seamlessly past Pontresina:

• Celerina (~5.0 km on): A flat cruise along the Engadin plain toward the sun-drenched meadows of Celerina, recognizable by its famous, isolated San Gian church tower.

• Samedan (~8.0 km on): Finish up in the historic heart of the Upper Engadin capital, walking past beautifully preserved stone houses with traditional sgraffito artwork.

Arrival in Pontresina: Refueling & Transport Hub

Arriving at Pontresina Train Station marks the end of the core expedition. Beyond being a key logistics node, it is the perfect spot to warm up and reward your efforts:

• Refueling Options: Right at the station or just a short walk into the village center, you will find fantastic culinary options...

• Excellent Public Transport: Pontresina boasts superb transit connections. The train station links you directly back to St. Moritz, Landquart, or Chur via the reliable RhB networks. 

Critical Mountaineering Logistics

• Pre-Trip Weather Protocol: Before you even leave, it is useful to cross-reference the local winter meteorological reports and avalanche bulletins.

• Warning: Ice Cave & Cliff Instability: Glacial tunnels are inherently volatile. Because the tongue is now hung up on a steep cliff face, it can trigger ice avalanches, cave collapses, and rapid rockfalls. Access past the viewpoint has strict local safety prohibitions - please observe the signs…

• NB: I do not recommend anyone do what I did, it is inherently dangerous and you do so at your own risk of injury or even death.

Mandatory Winter Gear: 

Do not attempt this route extension without crampons (or microspikes if you must), a climbing helmet (essential for the fractured rock and ice-fall hazard near the caves), a high-lumen headlamp (optional but sometimes useful), an ice axe or at least winter trekking poles, and snowshoes with solid under-frame teeth for breaking trail along the powder-heavy riverbanks. 

Guide Recommendations: 

If you lack advanced winter navigation and crevasse/moraine/avalanche assessment skills, secure a certified professional guide through the mountaineering schools in St. Moritz or Pontresina. Note that there is a guided glacier trail from Diavolezza to Morteratsch, but I have no further details about it…

This route was hiked by the Author on the 8th of February 2025. See my other articles for hikes in this area. Contact me by email for photos or to ask questions.