After leaving the car in the parking lot near the Pian di Gembro Refreshment Bar, take the path immediately after the snowcat shed for the cross-country ski slope, ascending to the right. The first stretch consists of a proper path which then becomes a road and reaches the junction that climbs towards "Prosolone." Keeping to the right and passing some huts, you move toward Monte Borca; the road continues flat until it reaches some hairpin bends and, following the left forks, returns toward the "Prena" plateau.
The route passes a wonderful panoramic balcony over the Orobie and, descending, reaches the locality "Prosolone" from where you return closing the loop.
To tackle the "Prena" path, a normal snow hiking equipment is recommended (snowshoes, poles, or possibly crampons).