One branch of the old Toronto, Grey and Bruce Railway (TG&B Railway) ran from Toronto to Owen Sound. A second branch split off at Fraxa Junction near Orangeville and went to Harriston and Teeswater. The Owen Sound branch, known as the Grey Extension, was opened in August 1873.

The TG&B Railway was a narrow-gauge railway and this was the cause of its demise. The narrow gauge became a problem due to wear and tear caused by of the amount of traffic it carried. In its efforts to convert to a standard gauge, the railway company ran out of money. The railway eventually fell into the hands of the CPR before it was dismantled in 1997.

From Orangeville, the railway line crossed what is now Dufferin Road 109, formerly Highway 9, just before the Mono-Amaranth Township Line. This section of the line still exists. The line then crossed Dufferin Road 11 at Fraxa Junction and turned north to Shelburne, running alongside Dufferin 11. After Shelburne, the line generally followed the route of the T&S Road to Markdale, except for a section from just south of Dundalk to just north of Flesherton where it moved about a mile west of the road.

As you travel along Dufferin 11, you can see where the old line crossed Dufferin 11 just north of Crombie. You can also see route of the old line as it crosses the 200 sideroad north of Dundalk and as it crosses the West Back Line between Flesherton and Markdale.