Around the Mattmark reservoir in Saastal valley

Mattmark Stausee


Gentle walk from Europe’s largest earth dam around a peaceful reservoir framed by dramatic mountains. Western leg is pushchair-accessible. 




8.04 km


2:15 h


The road up the Saastal valley comes to an end at Europe’s largest earth dam: the Mattmark dam (2,200 m). This is the starting point for a charming walk around the Mattmark reservoir. The trail roughly follows the shores of the lake; on the western side, it is even suitable for pushchairs. 

The reservoir may be man-made, but the surrounding scenery has retained all its natural grandeur. The slopes to the west lead up to two of the valley’s mightiest glaciers, the Allalin and the Schwarzberg, which adorn the slopes of the Allalinhorn and neighbouring 4,000-metre peaks. At the southern tip of the lake, a trail leads up to the Monte Moro Pass on the border with Italy, marked by a golden statue of the Madonna. 

At the crest of the dam, the friendly restaurant provides a handy stop for refreshments before or after the walk. The visitor centre offers an interesting insight into this innovative green energy scheme. The reservoir can hold 100 million cubic metres of water. Hydroelectric power stations further down the valley can generate nearly enough electricity for all the households in Valais. Thanks to the Mattmark and about 40 other dams in Valais, about 30 per cent of all hydropower in Switzerland is generated in this one canton alone. 

However, construction of the dam took a heavy human toll. On 30 August 1965, part of the Allalin Glacier high above the construction site detached. About 2 million cubic metres of rock and ice came crashing down, burying the canteen and staff accommodation under up to 50 metres of debris. In all, 88 workers lost their lives. 

Today, the valley is once again a place of tranquillity. Walkers have a good chance of spotting local wildlife along the trails around the reservoir: bring binoculars as well as a hand lens to admire local wild flowers. 


  • Leisurely walk with few climbs around a scenic reservoir
  • Restaurant by the dam, interesting visitor centre
  • High-altitude (2,200 m) mountain terrain, good chances of spotting wildlife 

Turn-by-turn directions

The bus stop, car park and restaurant are all located at the western end of the crest of the dam, and this is where the trail begins. Our hike loops the reservoir anti-clockwise. The first section leads southwards along the lake’s western shore via a broad alpine track, surfaced in parts. Our route leads through the left-hand tunnel; openings in the rock at regular distances reveal views of the lake. Beyond, the trail climbs gently to reach a junction by a waterfall. We take the left turning to reach a second tunnel. This is not illuminated, but walkers can bypass it by following the trail to the left, which involves a few steps. Beyond, the trail continues in the open air all the way to the end of the reservoir at Distelalp (2,224m). Here, the trail crosses the river via a bridge before following the eastern shore all the way back to the dam. A short stroll along the crest leads back to the restaurant and the starting point of the hike. 


Mattmark dam (2205m)


Mattmark dam (2201m)

Author's recommendation

Holders of the “Citizen’s Pass” enjoy free travel on all postal buses in the Saastal valley (including to the Mattmark dam) and on all summer lifts in Saas-Fee (excluding Metro Alpin), plus many discounts in resort. 

Technical information












Best time of the year

  • Jan
  • Feb
  • Mar
  • Apr
  • May
  • Jun
  • Jul
  • Aug
  • Sep
  • Oct
  • Nov
  • Dec


  • Scenic
  • Geological highlights
  • Fauna
  • Suitable for strollers
  • Round trip
  • Refreshment stops available
  • Family-friendly
  • Flora
Getting there

Public transport

Train to Visp. Change on to postal bus for Saas-Fee, alight at Saas-Grund. Change on to postal bus for Mattmark (final stop). Find full timetable information at sbb.ch.  


A9 motorway and main road up the Rhône valley to Visp. Turn south up the Vispertal valley, and at Stalden turn left up the Saastal valley. At Saas-Grund, instead of taking the turning for Saas-Fee, continue further up the valley through Saas-Almagell and follow the road all the way to the end – at the Mattmark dam.  


Car park near crest of Mattmark dam.  


  • good footwear
  • clothing suitable for the weather: always carry a waterproof jacket
  • hat or cap
  • sunscreen
  • bottle for water, picnic
  • camera
  • hiking poles (optional)
  • printout of this hike (click “Print” icon, top right, to download)

  • Swimwear

Safety information

Use of the trails and the information on this website is at hikers’ own risk. Local conditions may entail changes to routes. Valais/Wallis Promotion accepts no liability for the accuracy and completeness of information on this website.

  • Bring a map. Download full description of this route including large-scale map by clicking on “Print” icon, top right of this page.
  • Use marked trails only, and observe all signposting – for your own safety, to safeguard grazing animals and to avoid disturbing wildlife.
  • Close gates after passing through.
  • Please be considerate to other trail users, and to the plants and animals.
  • Do not leave any waste in nature. 

  • Take extra care protecting yourself from the sun at altitude. UV radiation can be exceptionally strong, even in cloudy weather.
  • Plan hike carefully: take into consideration fitness level of each participant, weather forecast and season.
  • Weather conditions can change quickly in the mountains, without warning. Appropriate clothing is therefore essential, along with adequate supplies of food and water. In uncertain weather, turn back in good time.

  • Inform others of the route you plan to take. Whenever possible, avoid going alone.
  • Do not venture onto glaciers without a mountain guide.
  • Take note of the warning signs that point out the constant danger in river beds and along watercourses below dams and reservoirs: water levels may rise rapidly without warning.

Additional information

More information about the destinations: 


The tourist office in Saas-Almagell has got brochures and information material about hiking in the region.


SwissTopo maps 1:25’000: 2526 Saas-Fee


This activity is brought to you by Valais/Wallis Promotion