Three Sisters Island Lighthouse, or “Sisters Island Light” as viewed from downriver. The Canadian Island “Grenadier” is on the right, and the main US shipping channel is on the left. No longer an active navigation light, the more modern red beacon now marks the outer limits of the channels north side. Long ago, the glow of this light was actually a gas flame. History has it that the vent tube for the light would be clogged by the shad fly, thus snuffing the light out. The Lighthouse Keeper had to constantly get up at night a clear the vent and relight the flame. Another story talks of the death of several deep divers, who were laying charges on the river bed to deepen the channel for the larger cargo vessels traveling the river. During a nighttime thunder and lightening storm the barge was struck, exploding the dynamite and killing all the divers in their sleep.
Source: Thousand Islands Historical Records.