ðɪ ˈoʊldɪst pˈoːɹʃən ʌv hˈaɪweɪ twˈɛlv wʌz ɚɹˈɪdʒɪnəli nˈoʊn æz ðə kˈoʊldwɔːɾɚ pˈoːɹɾɪdʒ ænd lˈeɪɾɚ ðə kˈoʊldwɔːɾɚ ɹˈoʊd, kənˈɛktɪŋ ðə mˈɑːdɚn sˈaɪts ʌv ɔːɹˈɪliə ænd kˈoʊldwɔːɾɚ baɪ ɐ tɹˈeɪl.
The oldest portion of Highway 12 was originally known as the Coldwater Portage and later the Coldwater Road, connecting the modern sites of Orillia and Coldwater by a  trail.