Washington State Route 501
| Erwin O. Rieger Memorial Highway | ||||
The existing highway is highlighted in red. The proposed completion is shown in dashed purple. | ||||
| Route information | ||||
| Auxiliary route of I-5 | ||||
| Maintained by WSDOT | ||||
| Length | 13.97 mi (22.48 km) | |||
| Existed | 1964–present | |||
| Southern section | ||||
| Length | 11.00 mi (17.70 km) | |||
| South end | I-5 in Vancouver | |||
| North end | Ridgefield NWR near Vancouver | |||
| Northern section | ||||
| Length | 2.97 mi (4.78 km) | |||
| West end | Main Street in Ridgefield | |||
| East end | I-5 in Ridgefield | |||
| Location | ||||
| Country | United States | |||
| State | Washington | |||
| Counties | Clark | |||
| Highway system | ||||
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State Route 501 (SR 501, designated as the Erwin O. Rieger Memorial Highway) is a 13.97-mile-long (22.48 km) state highway in the southern part of the U.S. state of Washington. It is split into two sections in Clark County, a north–south alignment connecting Interstate 5 (I-5) in Vancouver to the Port of Vancouver and the Ridgefield National Wildlife Refuge, and a west–east alignment connecting Ridgefield to I-5. Prior to the 1964 highway renumbering, SR 501 was designated as Secondary State Highway 1T (SSH 1T), established in 1937 and re-aligned to serve the Port of Vancouver in 1963.