Geology and Morphology
The Antrona valley stretches from the small town of Villadossola to the village of Antronapiana winding up between the Anzasca and the Bognanco valleys.
Giaciers formerly and surface waters later have shaped the valley's fascinating scenary: hence originates the deep gorge where the turbulent waters of the Ovesca stream flow, as well as the gentle green slopes spangled with villages.
Moraines, erratic boulders, streaks on the bare humpbacked rocks are the traces of the work of ancient glaciers nowadays nearly completely disappeared.
To embellish the rough beauty of the piace there are many lakes, both natural (cirque iakes, limited by morainic deposits) and artificial (reservoirs for the hydroeiectric energy generation).
As far as the geologic pattern is concearned, rocks are mainly represented by gneiss and ophiolithes, the latters being better known as "Antrona's green rocks", gneiss can be found in compact banks with steep wails, irregular ridges and pyramid-shaped peaks (orthogneiss: mountain range between the Anzasca valley and the Andolla peak) or else they are much more fragile and schistose (paragneiss: Iow Antrona valley).
The valiey is of noticeable interest for mining, which probably was more important in the past, thanks to the industrial expioitation of the iron ore deposits at the Ogaggia mountain pass, of gold at Locasca/Mottone, of pegmatite at the Alpe "i Mondei" (Alpe means pastures with a smail group of mountain houses) of Montescheno and aiso copper, silver, mica and "oliare" stone (the so called "laugera").
Several aspects present in the mountains, like climate (temperature, snow covering, thermal stress, wind), topography (exposure to the sun and slope of versants), edaphic factors (granulometry, pH, water, mineral salts, composition of humus, geologic nature of soil) and biotic factors (human intervention), interact one with another and bring about the environmental characteristics which the Alpine flora has to adapt to, by developing its peculiar morphoiogic and functional characteristics.
The Antrona valley belongs to the western Alpine section (Alpi Pennine) and is influenced by a continental-like climate.
Starting from the bottom plain up, at various height levels, crops and artificial (created by man for the cattle breeding) meadowlands stretch up to the Alpine grassland, a real natural garden which during the short summer bloom shows its most beautiful colours.
The mixed broad leaf woodland also starts from the bottom of the vailey: the prevailing species are chestnut and oak which at heights over 900 metres give way first to beechwoods and red fir woods and then to pine woods.
But the true symbol of the Alps is larch, which can reach the highest altitudes: the specimens at the Alpe Lombraoro are wonderful.
Rhododendron and bilberry grow up well amidst this conifer, forming thick carpets where they were once uprooted by the mountain dwellers to create new areas of pasture.
Nowadays the flora protection depends much on our respect, and it may be better to take a picture of a flower instead of picking it up.
The Fauna populating the valley does not differ greatly from that in the rest of the Ossola district.
Numbers of different species are present, but since direct sighting is often difficult, it's interesting to be able to recognize their "traces", that is the signs of their presence such as marks, food left-overs, lairs and hideouts.
Therefore we wilI realize we are not alone in our way in the wilderness.
It is not advisable to make a long Iist of all the species existing in the valley, though at Ieast the following specie should be recalled: the four ungulates characteristic of the Alpine arc: roe deer, deer, chamois and ibex; charming and noisy marmot, fox, badger, hedgehog and squirrel are also present; ermine and hare show their snow-white fur in winter and a more or less brown one in summer.
The Avifauna is well represented by the haugty figure of the royal eagle, as well as by buzzard, white rock ptarmigan and grouse; several are the species of passerines and ubiquitous is the alpine chough.
Amphibians like the "temporaria" frog, reptiles (lizards, green lizards, coluberids and viperids), some species of fresh water fish and multicoloured insects complete the faunistic picture.
In the higher Antrona valley a refuge and repopulation area was set up in protection of the animal populations showing an inadequate density, as welI as in safeguard of the Alpine environment as a whole.
Note: for the naturalistic cards, see Guida di Villadossola. - Ed. C.A.I. Sez. di Villadossola - 1996.