The communities of Port Lambton, Sombra, Courtright, Mooretown, Corunna and Froomfield are located along the parkway, all early settlements of the 19th century.

The St. Clair Parkway Commission was subsequently formed out of several committees in 1966, the ultimate result of a vision set forth by Alan Brander in 1949.

At its southern end, the St. Clair Parkway begins at an intersection with Dufferin Avenue immediately east of its crossing of Chenail Ecarté (The Snye) to the Walpole Island First Nation, and approximately 5 km (3 mi) west of Wallaceburg.

It proceeds north alongside The Snye, crossing Running Creek and passing the Roberta Stewart Wetland before transitioning from Chatham–Kent to Lambton County at Whitebread Line.

Each of the settlements along this portion of the parkway are centered at the concession roads that funneled inland settlers and goods to and from the river.

[3] The Sarnia Subdivision, at one time the principal means of communication between those settlements, roughly parallels the parkway to the east.

[6][7] After passing through Port Lambton, the St. Clair Parkway crosses the W. Darcy McKeough Floodway, a channel constructed in 1984 to protect Wallaceburg from flooding.

[2] Between Sombra and Courtright, the CF Industries nitrogen chemical plant as well as the decommissioned Lambton Generating Station rise above the flat farmland that abuts the parkway.

[1][9][10] Beginning at Courtright, the terminus of the former Canada Southern Railroad,[11] the parkway moves slightly inland from the shoreline and becomes consistently lined by residential properties.

[1] It crosses Baby Creek and travels through Mooretown, with the Sarnia Subdivision briefly running alongside the parkway north of the village.

[11] The arrival of the Erie and Huron Railway (today's Sarnia Subdivision) in 1886 temporarily supplanted the role of the muddy river road.

[3] In an effort to reduce the quagmires that developed in wet conditions, a layer of gravel was placed down on the road in the late 1800s; mud was henceforth replaced by dust.

The opportunity to draw tourism and trade was also widely recognised, resulting in the formation of the St. Clair River Association in 1925.

[29] The association continued to send delegations to Toronto to argue for the designation of the river road as a highway over the next several years, and began a beautification program of planting trees along the route.

[34] The designation came just weeks before the 1934 Ontario general election that saw Lambton West incumbent Conservative MLA Andrew Robinson McMillen replaced by Liberal William Guthrie.

At a ceremony in Corunna on the evening of October 27, 1943, Minister of Highways George Doucett cut a ribbon to officially mark the completion of the work.

Perhaps more than any one person, former Wallaceburg mayor Alan Perry Brander was responsible for the idea of a continuous parkway along the St. Clair River.

[46][48][49] Speaking of the tourist potential to the Wallaceburg Rotary Club, Brander laid out his vision for a beautified living museum, akin to the Niagara Parkway or Colonial Williamsburg, along the riverfront.

[50] In 1952, and now with the support of the DHO, the program expanded to include the entire highway between Wallaceburg and Sombra, with an additional 1,300 rose bushes prepared for planting that summer.

[52] The "Queen of the Rose Trail" was chosen by judges selected by local newspaper publishers each August long weekend over the next three years.

[58] By 1961, the bushes had begun to revert to a wild unkempt state in many places, although Brander continued with his work until his death in 1965.

[15] During the late-1950s, the Saint Lawrence Seaway project created a navigable lock system between the Atlantic Ocean and Lake Superior, while simultaneously reclaiming properties along the shoreline for parkland.

Around the same time, both Kent and Lambton counties formed parkway committees composed of local business leaders and politicians.

[70] Following several years of negotiations with the Aamjiwnaang First Nation (then the Chippewas of Sarnia),[71][72] construction of the new inland route of Highway 40 began in July 1972.

[74] A second contract, awarded in 1974, extended construction south an additional 11.0 km (6.8 mi) to Lambton County Road 2 (Bentpath Line) near Sombra.