The Missisagi Lighthouse was built in 1873 to aid travelers through the dangerous Mississagi Straits. Due to an off shore magnetic reef the navigational systems in ships would be thrown off causing many shipwrecks.
In 1881 the Fog Horn Plant was built to further aid travelers through the dense fog that often covers the Straits in the early morning.
The North Channel runs between Manitoulin, St. Joseph, Drummond, and Cockburn Island and the main shores of Northern Ontario. This passage is preferred by many sailors over the unpredictable open waters of Lake Huron. Although it is protected from the ever changing harsh weather that is faced in the openness of Lake Huron, the North Channel has its own dangers including protruding rocks, magnetic reefs and many other fierce obstacles sailors must face.
To enter the North Channel many sailors come in the southern entrance through the Missisagi Straits in between the west end of Manitoulin Island and Cockburn Island.
In 1855 a contract resulted in the construction of Lake Huron's Six Imperial Tower's as well as a Lighthouse on Badgeley Island, St. Joseph Island, and along the Mississagi Straits. Due to the high and unpredictable expense of building the six imperial towers, these Lighthouse projects were postponed.
Finally, in 1873 the Mississagi Lighthouse was built. The Department of Marine published the following description of the light in 1873.
" A new lighthouse was also erected last summer on the south-west end of Great Manitoulin Island, Lake Huron, for the purpose of general navigation, and to guide vessels through Mississagi Straits. The light is a fixed white catoptric light, consisting of two mammoth flat-wick lamps, with 20-inch reflectors, and one circular burner lamp, with 20-inch reflectors, and can be seen at a distance of about 15 miles. Mr. John Miller was appointed keeper of the light, at a salary of $300 per annum, and the light was first exhibited on the 12th day of August last. The total cost of its construction, up to the 31st December last, was $2,073.10. "
John Miller, along with his family of four children, was appointed Keeper of the Light in the summer of 1873 until November 1877.
In his spare time Mr. Miller would split wood and sell it to passing steamers for fifty cents a cord.
William Cullis replaced the Miller family as the Keepers of the Light. He also had a family of four children. While under Mr. Cullis's care the Superintendent of Lights above Montreal came for a visit and reported the lighthouse was in very good condition, that the family was re plastering the kitchen, as the old plaster did not have any hair mixed in with the lime, and had started to fall off.
Mr. Cullis purchased a 27 foot sail boat in order to obtain supplies at the remote location in which he resided. He also offered a $10 reward to the person that was able to create a trail to the property which was completed by a man named Mr. Robinson who lived on Bass Lake and was able to cut through the dense forest with a team of oxen in order to claim the reward.
The Fog Horn plant was built and operational on October 10, 1881 and stood 67 feet southwest of the lighthouse. This machine delivered a 10 second blast every minute during times of low visibility. This fog horn was operated by steam. However, sailors complained that the alarm was not satisfactory. This eventually convinced the Department of Marine to replace the horn with a steam whistle known as a wildcat. This whistle was complete with a piston that allowed the tone of the alarm to change. This alarm began as a low bellow and rose to a screech before returning to the low note. This provides a range of frequencies that could be more easily heard by mariners. This alarm proved to be satisfactory to those who depended on it.
In 1897 the Fog Horn Plant was enlarged to allow for another locomotive boiler that was constructed by John Inglis & Sons of Toronto.
November 1, 2906 the wildcat steam whistle was replaced with a diaphone that operated on steam powered compressed air. The Canadian Fog Signal Company supplied this plant for $5,747 and was installed in a newly built Fog Horn Plant 125 feet south of the lighthouse which cost $ 4,893. At a height of 33 feet above the waters of the Missisagi Straits the resonator gave two 3 second alarms every 45 seconds. The old fog horn plant was converted into an oil plant in 1916.