Registry offices in Piemonte and in Biella province were established in early 1800: it means that you could find information in Valle Mosso registrar as of that date.
So, if your ancestors were in Valle Mosso in the nineteenth or twentieth century, then you could try to contact the City Office of Valle Mosso to know more.In the next picture you can see the demographic trends in Valle Mosso from the Italian Unification (1861).
It could be important to know if the last name you are investigating is a frequent surname in Valle Mosso. As more your surname is common in Valle Mosso, as more it could be difficult to find the right info about your ancestors in Valle Mosso archives if you have not exact dates.
It could be useful for you to know that some of the most common surnames in Biella province are:
