I happen to have a 1984 copy of Ron Brown’s “Backroads of Ontario”, and Joyce and I went for a drive today, following the Great Pine Ridge west from Yonge Street
There is a later version of the book, from 2019, but that’s not what I’m writing about: I discovered something I should have guessed.
You can create an overlays with the route in Open Street map, and publish it as a link.
If you go there, you’ll see something that look like this, except it’s editable:
The tools is quite lovely, and only a little harder than marking a paper map with a highlighter.
Go thou, and do likewise, at https://umap.openstreetmap.fr/en/