Palmerston in Minto in Wellington County, Ontario — Central Canada (North America)
Heritage Armour Stone
Photographed by Tim Boyd, September 25, 2026
1. Heritage Armour Stone Marker
1891-1994 Portal St. Clair Railway Tunnel between Sarnia, Ontario, Canada and Port Huron, Michigan, U.S.A.
Built by the Grand Trunk Railway.
First subaqueous railway tunnel in North America.
The tunnel is a Registered Natural Historic Landmark, U.S.A. It is designated a Civil Engineering Landmark by the CSCE and ASCE. Tunnel entrance armour stone now lines perimeter of the Palmerston Lions Heritage Park, Palmerston, Ontario, Canada 2009.
Topics. This historical marker is listed in this topic list: Railroads & Streetcars. A significant historical year for this entry is 1891.
Location. 43° 50.054′ N, 80° 50.905′ W. Marker is in Minto, Ontario, in Wellington County. It is in Palmerston. It is on Main Street East 0.1 kilometers east of Janes Street, on the right when traveling east. Touch for map. Marker is at or near this postal address: 325 Mill Ln, Minto ON N0G 2P0, Canada. Touch for directions.
Regionally, this marker is in the Huron-Perth-Waterloo-Wellington Area and in Southwestern Ontario. It is also in Central Canada. Globally, it is in North America, the Western Hemisphere, the Western World, and
this page online
Other nearby markers. At least 8 other markers are within walking distance of this marker: Steam Engine (Old) 81 (Palmerston) (within shouting distance of this marker); In Proud Memory of CN Employees (within shouting distance of this marker); Arthur (Art) William Carr (within shouting distance of this marker); C.N.R. Park (about 210 meters away, measured in a direct line); CNR Park Blue Print (about 210 meters away); Palmerston Methodist Episcopal Church (about 210 meters away); a different marker also named C.N.R. Park (about 210 meters away); The Founding of Palmerston (about 240 meters away). Touch for a list and map of all markers in Minto.
Photographed by Tim Boyd, September 25, 2026
2. Heritage Armour Stone Marker
3. The St. Clair River Rail Tunnel, 1907 postcard
Source: Wikipedia (public domain)
Credits. This page was last revised on October 15, 2026. It was originally submitted on October 14, 2026, by Tim Boyd of Hamilton, Ontario. This page has been viewed 11 times since then. Photos: 1, 2, 3. submitted on October 14, 2026, by Tim Boyd of Hamilton, Ontario. • Andrew Ruppenstein was the editor who published this page.
