The Saint Clair Parkway is maintained by the Saint Clair Parks Commission. The road was the original Highway 40, which was re-aligned about 5 km inland from the river on a new alignment as a Super-2 expressway (with intersections) from Wallaceburg to Sarnia. The road provides a nice alternative or scenic route from Wallaceburg to Sarnia, going through the towns of Port Lambton, Sombra, Courtright, and Corunna. It turns west along Vidal St. and Churchill Line (Lambton County Road 34), meeting its new alignment in the southern area of Sarnia.
In Chatham–Kent and Lambton County, its designation is County Road 33.
The St. Clair Parkway was managed by the St. Clair River Parkway Commission, (Founded in 1966) until the Commission was disbanded in February 2006. At that time the parks were reverted to local municipal/town/township control.