The development of the region proceeded slowly throughout the 18th century. The first farm was established only in 1731. What is now the municipality of Mont Saint-Hilaire was the location of three villages at that time. The first was situated near the river and was the first to develop. The second, located on the mountain near the outflow of Lake Hertel, was founded in 1745. The rail station village was developed last with the arrival of the railroad. In 1746 there were only 30 inhabitants in the entire seigneury. In 1751, clearing began on the lower flanks of the mountain and by 1768, a road along the flank of the mountain was established with orchards being planted on the south-facing slopes. This initial phase of European colonization of the region ended with the establishment of parish churches at Saint-Jean-Baptiste (1796) and Mont-Saint-Hilaire on the shore of the Richelieu River (1798).
The mountain village community owed its development to the stream and the energy that it provided. A mill was put into operation in 1750. You can still see the remnants of several mills, including the Maison Guérin, located near the entrance of the Reserve, an old seigneurial mill first constructed in 1775 and reconstructed in 1848 after being destroyed by fire in 1840.
A dam was constructed at the Lake Hertel outflow to regulate the water flow. In the 19th century, nine mills, a distillery, three tanneries, two forges and a foundry were powered by that energy. In 1850, about 1,500 people in 260 families lived and worked near the stream, clearly more than the number living in the parish village of Mont-Saint-Hilaire near the river.
In 1841, a large cross with a chapel at its base was erected on the Pain de Sucre summit. It was 30 metres tall and 9 metres wide, and people could climb up inside it. A winding trail with the stations of the cross led to the summit. Five years later, the cross came down in a violent storm. The chapel was completed destroyed by fire in 1876.
In 1844 the seigneury became the property of the Campbell family. Thomas Campbell built the Lake Hertel dam, rebuilt the mill, promoted the hydraulic industry and constructed the region’s first school. In 1851, he built the Café Campbell on the west shore of Lake Hertel and advertised railroad excursions from Montreal to this mountain retreat. The café was destroyed by fire in 1861.
His sons undertook the construction of the Hôtel Iroquois and completed it in 1874. It prospered until it was destroyed by fire in 1895. It is believed that it was located near the current Manager’s House.