Mountain Biking: La Marie Singletrack. St Ismier, Gresivaudan, French Alps - 709 m. (2,326 ft)

Thu, 25 February 2021


Minimum altitude: 260 meters

Distance: 19.2 km

Slope Aspect: East

Trip Reports

Vertical Climbed: 620 meters (2,034 feet)

Vertical Descended: 620 meters

Rating: 3


From St Ismier, climbed to the Tour d'Arces than past the Pierre Grosse (large rock), continue 500 meters. 100 meters before the traverse of the Corbonne river there is a small track that leads obliquely down the mountain. A bit of a dive at first, the trail then zig-zags and there are often dead leaves with hidden rocks. It is technical without being crazy steep. On the second half you cross and recross a river bed with lots of bumps you need to keep your speed over. The third act joins the bottom of the Corbonne single for a warm down before opening onto a field. Take a cross trail here back to St Ismier. One of the best singles in the sector. This trail is not a right of way and you may encounter problems with hunters so watch out if a hunt is in progress.

Trail is named after the Pierre de Grosse Marie (Fat Mary's Rock).

Trip Report

Junior was bored with the local singles so we decided to go further afield, the Corbonne? Too wet in winter. We had cross wires about where to go and so we headed to this single he didn't know. Super spot. I'd done it in the summer when it is a bit overgrown but at the moment it is fantastic. Not beyond our skills but testing the limits at times depending on the speed. A good descent too. On the way back we took in the Croix Trousset but I blew the front tire hitting a rock on the descent.


Dry, excellent riding conditions everywhere.


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