In 1872 John Chaffey opened a grist mill on the Opinicon Lake side of the bywash. He was a nephew of Samuel Chaffey who built the original mills in the area, which were demolished when the canal was built. The Dargavel family took over the mill and William Kerruish worked as the miller until 1922, when it ceased operation. Subsequently, the building served as a summer residence for the Phelps family. In 2016, the main floor of the mill became The Mill Art Gallery and welcomes visitors in the summer months.