The naturalistic value of the park is represented by the wood: a mixed oak wood whose dominant species are the sessile oak, the British oak, and the Turkey oak. The presence of four Quercus species favours the formation of several hybrids and intermediate forms which is difficult to catalogue. The chestnut tree and the false acacia are used as firewood, while in the past were mainly used for vineyard poles. The presence of the beech represents a residual of the beech woods spread around the area at the end of the last glacial era. In the underwoods there are the hazel, the ivy, and the honeysuckle.
Among charming landscapes, the hills mainly covered with woodlands
alternate with meadows, fields, and vineyards. From a geological point
of view, the area is part of the Tertiary basin of Liguria and
Piedmont. There are several clayey and sandy outcrops rich in
paleontological finds: shells, mollusks, and sea mammals remains.
The territory also bears witness of its historical and cultural past: first inhabited by prehistoric men, then by Sarmati tribe after which the valley has been named, and in the Middle Ages a feud of the Scarampi, Incisa, and Crova families. Val Sarmassa has been a source of inspiration for a great journalist and writer of the post-war period, Davide Lajolo. Born in Vinchio, he set many of his novels and essays in these lands.
The protected area is divided into two valleys, submerged by the sea in very ancient geological periods. Today it consists of a hilly territory where wild valleys covered with woodlands follow one after the other. The establishment of the Reserve mainly aims at protecting the paleontological heritage represented by fossils which have been found in some sedimentary strata outcropping along the walls of the valleys. They date back to the Pliocene (5-1.8 million years ago), when the sea covered the whole Po Plain up to the Alpine chain. Valle Andona and Valle Botto Reserve, including now also Valle Grande, also offers the opportunity to carry out interesting naturalistic observations. The hilly slopes which were once mainy cultivated with vineyards are nowadays covered with black locust trees, hornbeams, and British oak woods. The undergrowth is dominated by hazelnut tree, spindle tree, honeysuckle, and traveller's joy.