The most convenient access to the Rezzalo Valley starts from the village of Fumero. Shortly after Sondalo, along the SS38, take the exit for Le Prese and follow the signs for Frontale, climbing the valley slopes along a steep but scenic road until you reach the small hamlet of Fumero. From here continue to the locality Fontanaccia, where there is an essential but functional parking lot, the starting point of the hike.
The itinerary is also passable by joelette, but requires good organization: the terrain is uneven in places and has some challenging climbs, which is why at least four conductors are recommended.
The walk begins along a quiet dirt road that enters the coniferous forest. In autumn this section is particularly striking: the larch trees take on golden hues and the underbrush is tinged with copper and red, providing a warm and quiet atmosphere. On the way up, one encounters the huts of Pontela and further on the locality of Le Gande. The valley gradually opens up and gives way to its wide central basin, where at an altitude of 1,850 meters is the plateau of San Bernardo, dominated by the small alpine church of the same name, a true icon of the Rezzalo Valley.
At the marked junction (see waypoint), it is possible to detour left along the path that leads to Rifugio La Baita, an accessible structure where you can take a break and enjoy traditional Valtellina dishes. Instead, those who wish to continue exploring the valley can continue along the main track, which runs almost flat towards the interior of the Rezzalo Valley until the Merlo locality, equipped with a picnic area and fountain: an ideal place for a break surrounded by nature and the colors of the autumn foliage.