Washington State Route 129

State Route 129
A map of Asotin County with SR 129 highlighted in red
Route information
Maintained by WSDOT
Length	42.55 mi[1] (68.48 km)
Existed	1964–present
Major junctions
South end	OR 3 at Oregon state line near Anatone
North end	US 12 in Clarkston
Location
Country	United States
State	Washington
Counties	Asotin
Highway system
State highways in Washington Interstate US State Scenic Pre-1964 1964 renumbering Former
← SR 128 → SR 131

State Route 129 (SR 129) is a state highway in Asotin County, Washington, United States. It travels north–south at the southeastern corner of the state, connecting with Oregon Route 3 (OR 3) at the Oregon state line south of Anatone. The 43-mile (69 km) highway then follows the Snake River, which marks the Idaho state border, north to Clarkston and terminates at U.S. Route 12 (US 12). SR 129 also has a short spur route that connects to a separate intersection with US 12 in Clarkston.

The highway primarily serves as a connection between Clarkston, Asotin, and Enterprise, Oregon. An existing road connecting Clarkston to Asotin was incorporated into the state highway system in 1923 as a branch of State Road 3 and extended south to the Oregon border as part of Primary State Highway 3 in the 1940s. During the 1964 state highway renumbering, the Clarkston branch of PSH 3 was split into SR 128 and SR 129.