Leave of you Zapala (km 0) for RN22 toward the west. Until The Flagstones they are 55 km . Make 6 more km and then follow northwest address for RP21.
The road advances parallel to the Sour river, to right. It will cross flowing streams; from one of them, the Codihué, the French Gastón of Martignac left in 1888 in canoe and it arrived until Carmen of Patagonian. The basin of the Sour one has a great watering potential. Today it is watered in Huarenchenque, km 92, for pastures. In these fields the European hare is plentiful (Lepus eurapaeus europaeus).
In the km 117 you arrives to Loncopué, 3,000 inhabitants, town of services of the rural environment, possesses an organized camping site next to the bridge of the stream Loncopué. The construction of the town reflective different times and simple but varied styles.
Advance, in km 123 take left RP26, new and well signalled, assisting to caution for ice, In km 137 will sight strange rocky formations, as if they were high buildings semiderruidos; coming closer will see to left the magnificent Bay Cliffs, product of several erosion classes, of yellow loamy color (bay) and in incredible ways.
Some few more kilometers and some few pehuenes emerges (araucarias). Of the near and distant rocks, slopes that give greenery to the landscape sprout. In veranada time, of November to April, will cross with halos of male goats and tropillas of horses (yeguarizos like they call them in the field), In km 160, they begin to be noticed stone ranches, it plates, cane colihue, cardboard, usádas for the veranadores.
Km 162, aroma the lake Caviahue (or Sour), of blue intense and it forms arriñonada; the route to accompanies, going by pehuenes park. Km 173 you arrives to Caviahue.