Caption: The Cooksville Brick Company (opened in 1912 as the National Brick Co.) operated a large brick manufacturing plant and quarry north-east of Highway 5 (Dundas) and Mavis in Cooksville, located off the south side of CP's Galt Sub at Mile 16.02. Around a half a dozen small steam tank engines and a gas Whitcomb switcher were used in the quarry pit to move excavated material to the plant, as seen here working during their final year of switching the pit. Ground level photos taken that day were rushed, being told by employees to leave as it was dangerous (in hindsight, they were right!).

Cooksville Brick sold all their small engines in 1955 when they switched to using trucks in the quarry pits, and used a trackmobile to switch the remaining plant tracks. The plant and quarry were closed under Domtar ownership in 1995, and the site has since been redeveloped into a suburban Mississauga neighbourhood (with a number of quarry-themed streets).