Washington State Route 172
SR 172 is highlighted in red. | ||||
| Route information | ||||
| Auxiliary route of SR 17 | ||||
| Maintained by WSDOT | ||||
| Length | 35.01 mi (56.34 km) | |||
| Existed | 1964–present | |||
| Major junctions | ||||
| West end | US 2 near Waterville | |||
| East end | SR 17 near Leahy | |||
| Location | ||||
| Country | United States | |||
| State | Washington | |||
| Counties | Douglas | |||
| Highway system | ||||
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State Route 172 (SR 172) is a 35.01-mile (56.34 km) long state highway serving rural Douglas County in the U.S. state of Washington. The highway travels north from U.S. Route 2 (US 2) near Waterville through Withrow and east through Mansfield before ending at SR 17 at Sims Corner. The highway follows the route of a county road built in the 1930s and signed as Secondary State Highway 10B (SSH 10B) in 1955. SSH 10B became SR 172 during the 1964 highway renumbering and served a daily average of less than 700 vehicles in 2011.