Cormac is a small rural settlement situated within the former Sebastopol Township, now part of Bonnechere Valley in Renfrew County. Established in the latter half of the 19th century, the community took its name from Fr. James MacCormac, the influential Irish Catholic priest who founded St. Ann’s Parish in 1867. The church, still standing today along County Road 512, became the focal point of the hamlet and a symbol of the area’s cultural and spiritual identity. Though never formally incorporated, Cormac functioned as a service and gathering point for surrounding farmsteads, with a schoolhouse, ballpark, and seasonal fairs anchoring community life well into the 20th century.

From a land surveyor’s perspective, Cormac presents a relatively intact example of Ontario’s concession-lot system. The township grid laid out under the Crown’s original survey remains largely unaltered, though some deviations occur around the church site and long-used farm lanes that predate formal road construction. Parcel histories here tend to reflect stable agricultural occupation, but title retracement may involve reconciling fence lines, drainage cuts, and informal severances. Surveys near St. Ann’s and along County Road 512 occasionally intersect with church-held lands or Crown reserve parcels, requiring consultation of both registry records and parish archives.