The region our Town occupies today was, many thousands of years ago, submerged by the sea of Champlain, a name given to an extension of the Saint-Lawrence gulf which, in a post-glaciation period, covered the present St-Lawrence valley as far as the mouth of the Great lakes.
The waters of that sea withdrew little by little and there was nothing left, so to speak, but sand on the Saint-Lazare territory. In the course of centuries, vegetation gradually covered the sand and in the 19th century, many species of trees (white pines, red pines, Canadian hemlocks, yellow birches and sugar maples) could be found in our region.
Around 1850, the Gillies brothers obtain timber rights in the region; they built a saw mill and cut down a great number of trees. Because of this deforestation and the clearing of nearby lands, there are not enough trees left to stop the soil from eroding; consequently, large quantities of sand are carried along each spring, by the waters from melting snow.
In 1928, Soulanges and Vaudreuil councilmen meet the Quebec Land and Forests Minister and discuss with him, the means by which this situation can be corrected. A project of reforestation of the dunes located at the southwest extremity of the parish is then put forward.
In 1929, Soulanges and Vaudreuil representatives take a government employee to visit the site in order to delimit the lands to be used for the future plantation site. The reforestation project authorised and financed by the Quebec government was, in view of its importance, unparalleled at that time in Quebec. The same year, a decision of the municipal council authorises the municipality to “acquire by mutual agreement or by means of expropriation, from all the owners concerned, the lands or parts of the lands required for the reforestation.” In the course of the summer, the purchase of the lands is completed and the work begins in the fall of the same year.
In the spring of 1930, 20,000 mugho pine seedlings are planted along with white spruces and black spruces. Later, red pines which are the conifers best suited to the sandy soil of Saint-Lazare, are planted. This reforestation put an end to the soil erosion and protected the lands which became cultivable again. The men no longer had to shovel and transport the sand which blocked ditches and accumulated on roads with high winds, making the roads impracticable.