The ever-increasing harvest of this cereal prompted some people to open flour mills to accommodate those who were suitable for this crop.

By 1855, the exploitation of wood was almost as important as agriculture, because it had become insufficient for the colonists; while the interior of the country changed into clearings, the establishments multiplied rapidly, for during that year the parish possessed five sawmills; two in Port-au-Persil, owned by Louis Tremblay and William Price (merchant), two in Port-au-Saumon owned by Joseph Dallaire and Hypolite Truchon and a last was built at the Black River by Thomas Simard.

The population could also count on two general merchants: Mr. Alexis Gagnon at Port-au-Saumon and Baptiste Tremblay at Black River.

At the end of the 19th century, agriculture still held first place in Saint-Fidèle; wheat, potatoes, barley, oats, buckwheat, peas, alfalfa, rye and flax were sown.

Immediately the company Pennington and Gagnon made undertake on the river Port-au-Saumon the construction of a dam in order to imprison the wood.

This tragic event is probably responsible for the arrival of a new timber company at Saint-Fidèle; Mount Murray Woodland Corporation headquartered in New York.

In 1924, there were three general stores, a butter factory, three cheese factories, three sawmills, three iron shops and two butcher shops, the most famous of which was that of Germain Gagnon, resident of Rang Saint-Paul, who, in order to give more service to his clientele sold his goods from door to door.

In 1925, for whatever reason, the Mount Murray Woodland Corporation was replaced by the International Paper company whose contactors were Arthène Bélanger and Frères.

In those days, the method of cheese making required more manual work, and the possibilities of preserving this dairy product in cold rooms much less sophisticated than those of today entailed a certain risk.

In 1962, the Tremblay bought the Fromagerie Savard of Baie-Sainte-Catherine and this is the beginning of the construction of the current modern plant to combine the operations of manufacturing butter and cheese.

In 1968, La Crémerie St-Fidèle bought the manufacturing permit for the Éboulements cooperative, and in 1969, the bulk of milk was collected.

Since then, Crèmerie Saint-Fidèle has won a first prize for the production of its Emmental cheese at a national exhibition in Toronto.

In 1988, brothers Lucien and Clément Tremblay decided to sell their business to the Coopérative Agricole de la Côte Sud.