Over the years, Île Plate has also been referred to as St. Peter’s Island, Plateau Rock, and Flat Rock.
The Department of Marine provided the following description of the lighthouse in its annual report in 1883:
During the past season a new lighthouse was erected on the small island known as Plateau or Flat Rock, off Point Peter, Gaspe, and the light put in operation on the 20th of September last. A revolving red catoptric light is shown, attaining its greatest brilliancy every 30 seconds, and elevated 77 feet above high water mark, and it should be visible 10 miles, from all points seaward, in clear weather. The building is of wood, painted white, and consists of a square tower 50 feet high, with keeper’s dwelling attached. The sum of $2,156.82 was expended on account of this lighthouse during the past fiscal year.
Benjamin Asselin was appointed the first keeper of the lighthouse on Plateau Rock at an annual salary of $300, but he resigned after just a few months and was replaced by Thomas D. Bond, who was hired at an annual salary of $350.
In 1895, the station’s cistern was cleared, cemented, and painted, and the foundations of the buildings were repaired with material sent from Quebec. The total cost for these improvements was fifty-five dollars.
A new lighthouse was built on Île Plate in 1924 in the form of a white, square, wooden dwelling with a red lantern room centered atop its hipped roof. The characteristic of the light was changed at this time from a red flash every seven seconds to a white flash with the same period. The focal plane of the new light was seventy-three feet above the surrounding water.
Around 1952, a red, square, skeleton tower was erected on Île Plate. The light retained its previous characteristic of a white flash every seven seconds, but it now had a focal plane of eighty-one feet.
Today, a square, skeleton tower is used on Île Plate to display a white flash every six seconds at a focal plane of sixty-eight feet.
Keepers: Benjamin Asselin (1883 – 1884), Thomas D. Bond (1884 – 1896), George St. Croix (1896 – 1909), John Thomas St. Croix (1909 – 1913), W.A. St. Croix (1914 – 1916), G. Cotton (1916 – 1932), Mrs. G. Cotton (1932), M. Mahoney (1932 ), A. Dupre (1933 – at least 1937).