The flour and grist mill was built in the early years of the 1800s on land sold to Joseph Keeler in 1811, according to registry office records. Situated to the west of what is now Ontario Street in Colborne, the mill was thought to be at least two and a half storeys above ground and one and half below. It is likely that the mill had a “tub” wheel inside the building below ground level at the north end to drive the machinery.