In 1906 and 1907, multiple sets of range lights were established to guide mariners through the archipelago, including Gallia Bay, Île des Barques, Île du Moine, Sainte-Anne-de-Sorel, Île de Grâce, and Île Dupas. A concrete pier, measuring twenty-seven feet square at its base and tapering to fifteen feet square at its top, which was fourteen feet high, was built at Sainte-Anne-de-Sorel in 1905 to support the front range tower. The Sainte-Anne-de-Sorel Range Lights were placed in operation on August 22, 1906 to mark the thirty-foot-deep and 450-foot-wide ship channel through Île de Grâce traverse, from the west end of Île des barques to the curve below Sainte-Anne-de-Sorel.
The following description of Sainte-Anne-de-Sorel Range was published shortly after the lights were established:
The front lighthouse, a square white building surmounted by a square red lantern, all 19 feet high, stands on a concrete pier, on the southern shore of the St. Lawrence, about 2 ¼ miles below Sorel, and exhibits, at 35 feet above high water, a fixed white light, visible, in the line of range 2 miles.
The rear lighthouse, a brown square steel skeleton tower, with white wooden slat work on upper portion of side facing channel, white inclosed watch room, and lantern roof red, the whole being 80 feet high, stands 723 yards, 235°, from the front lighthouse and exhibits at 98 feet above high water, a fixed white light, visible, in the line of range 5 miles.
These two lights in line, 235°, lead up from the intersection of their range line with Gallia Bay lower range, at the bend off the southeast point of ile a Lapierre, nearly to the intersection of their range line with Ile du Moine upper range near lightbuoy No. 136 L.
Frs. Lanicault was hired as the first keeper of the front range light at an annual salary of $100, while Pierre Counoyer received the same amount for tending the rear light.
By 2011, the original rear tower had been replaced by an eighty-three-foot-tall, tripod, skeletal tower that displays a fixed green light along the range line. The front tower is now equipped with two lights: a fixed green light in its lantern room that shines along the range line and a fixed green light mounted atop the tower that is visible 360°.