This trail is part of the Bernina Express
ride which is marked with the standard red and yellow waymarking signs as trail number 673, but note that I wasn't able to find any signs near the start of this segment. But the only other option was to go up a mountain, and the Bernina Express
ride ends down in the valley so downhill seemed like a good option.
This trail starts at a small farm at the upper end of the Val d'Urse (Urse Valley). It is a short, fun, and challenging singletrack going steeply downhill along the valley paralleling the creek.
This singletrack is a bit rocky and narrow. Watch for farm animals and electric fence openings on the singletrack. The cows are generally docile if you do not approach too closely but pay attention for mothers with calves.
Just where the singletrack ends at the forest road, you'll have a beautiful view of the Val di Poschiavo and Lago di Poschiavo (Poschiavo Valley and Lake). You can follow the forest road down into Poschiavo and the train to get back to wherever you've come from.