A historic landmark in Mississippi Mills will be closed to all traffic starting May 11, 2026, as Lanark County begins the second phase of a major rehabilitation project on the 5 Arches Bridge. The closure is expected to last until mid-November 2026 while crews work to preserve the 125-year-old structure.
The bridge in Pakenham is widely recognized as the only five-arch stone masonry bridge in North America and serves as an important historic crossing for the community. Because no through traffic will be permitted at the bridge location, drivers must use a signed detour route following Kinburn Side Road, Upper Dwyer Hill Road, and Galletta Side Road to return to County Road 29.
The contract for this phase of the project has been awarded to BEI Bonnechere Excavating Inc. at an estimated cost of $1.6 million, which is being funded from county reserves. Planned improvements include essential masonry and stone repairs, updates to the road approaches, and the installation of new lighting both beneath and on the bridge to enhance safety.
This work follows the completion of an initial phase in 2025, which focused on underwater substructure repairs and strengthening the bridge piers. According to Lanark County Public Works Director Sean Derouin, these ongoing efforts represent the county’s commitment to maintaining this unique heritage site for long-term use.
