"snake pass" and "jawbone" aren't Franglais'd...
No, theyre Yorkshire, but they wont get called Cote de passe de serpent for instance it will be Cote de snake pass.
Jawbone was actually Cote d' Oughtibridge last time i think, because the road is called Oughtibridge lane. Not Cote de Maxillaire de la baleine. Literally its called Jawbone because they claim there used to be the jawbone of a whale up there marking the summit.