Published on 31 August 2008 | by Pierre-Alexandre

Lacs d’Emosson, Traces de dinosaures, and Col de la Terrasse

Long ago, on the beach of Emosson, some clay dried. Later, some 240 million years ago, a herd of archosaurs (ancestors of dinosaurs and crocodiles) passed; They have engraved their tracks in the clay. The water covered them and protected them. Over the course of geological time, sediments have been deposited on several layers. Later, during the uprising of the Alps, the oldest lands were raised.
Since then, erosion has done its work, and on August 23, 1976, geologist G. Bronner discovered what is today the most significant deposit of tracks left by these reptiles.
So here is the purpose of this hike that I propose. A detour through the Col de la Terrasse will offer a dazzling view of Argentière Glacier and Glacier du Tour and the Lac du Vieil Emosson.
Be careful: this hike cannot be made before the end of June as big névés still subsist at that time.

Difficulty: Hard
Altitude: 2,648 m at the Col de la Terrasse, 2,370 m at the Traces de dinosaures
Route: 6 hours 30 min
Elevation Gain: 880 meters
Round-trip: 11,8 km
Map: IGN 3630 OT

Getting There

From Chamonix, continue in the direction of Argentière then Vallorcine. Cross the Swiss border and turn left shortly afterward towards Finhaut. From there, follow the road that rises frankly to the parking lot of the dam. Please note that due to work on the site of Emosson, access to the dam is restricted. Refer to this website for more information: http://www.emosson-lac.ch/.

GPS Coordinates (WGS 84) of the Starting Point : 46.067829, 6.936626

Ascent

From the parking lot, go down on the dam and continue along the paved road. You have to leave on the left a first path that goes in the direction of the Col du Passet, and take the following one in a curve on the right, signposted “Traces de dinosaures par la Gorge de la Veudale.”
The path, marked with cairns along the way, quickly gets into a canyon dominated by Tête de la Veudale.

After about two hours, a short ascent allows reaching a small pass where névés are often present. From here, on the left, a signposted pathway reaches the Col de la Terrasse in 40 minutes. The climb is delicate if the snow is there: in this case, only the cairns clearly visible guide the hiker to the Col de la Terrasse. On arrival, you will notice the vertiginous path rising from the Chalets de la Loriaz.
It is now necessary to turn back to descend to the small pass and, from there, continue in the direction of the site of the tracks of dinosaurs long awaited, located 100m lower. Wire fencing delimits the fairly extensive site. Facing the site, the imposing mass of the Cheval Blanc dominates the valley and the Lac du Vieil Emosson below.