The Rosseau-Nipissing Road
Designed to encourage settlement in what is now the Parry Sound District, the Rosseau-Nipissing Road was authorized by the government in 1864. A survey was completed the following year by J.S. Dennis, provincial land surveyor, and construction began in 1866. Commencing at Cameron Bay at the north end of Lake Rosseau, it ran 108 km northward to the South River terminating at Nipissing. By 1873 the road was open for winter traffic, and two years later was considered negotiable by wheeled vehicles. Although the road lost its importance after the railway between Gravenhurst and Callander was built in 1886, most of it is still used by local traffic.
Plaque via Alan L. Brown's site Ontario Plaques. Full page here.