Highway 417 begins at the border between the provinces of Ontario and Quebec, east of which the four lane freeway continues as Autoroute 40. The route proceeds west along the former alignment of Highway 17, which it has served to replace. It passes through a forested and agricultural landscape en route to Ottawa, serving the communities of Hawkesbury, Vankleek Hill, Casselman, Limoges and Vars. After approximately the route curves southwest while ramps provide access from the westbound lanes to Prescott and Russell County Road 17 and from County Road17 to the eastbound lanes of Highway 417. County Road17 was formerly part of Highway17 until it was decommissioned as a provincial highway in 1998. The route later meets the southern terminus of Highway 34 at Exit 27. Continuing southwest, the route meanders along the boundary between The Nation and North Glengarry, eventually encountering the northern terminus of Highway  138 — a highway built to connect Highway 417 with Highway 401 and Cornwall — east of Casselman. At this point, the freeway enters The Nation and diverges from the boundary.