State Route 401 (
SR 401) is a long
state highway in
Pacific County within the
U.S. state of
Washington. The highway originates at the north end of the
Astoria–Megler Bridge west of
Megler at an intersection with (US 101). The roadway travels northeast, paralleling cliffs, the
Columbia River and the South Fork of the
Naselle River to
Naselle, ending at . The road was designated
Secondary State Highway 12B (SSH 12) between 1937 and 1964, when SR 401 was created to replace SSH 12B. The Astoria–Megler Bridge, completed in 1966, replaced a ferry east of the bridge, where the highway originally ended, and is known locally as
Kingston Ferry Road. The roadway was extended west to the north end of the bridge, where it currently terminates. The former ferry terminal became the
Dismal Nitch rest area, named after the
Lewis and Clark Expedition's description of the place.