Washington State Route 181
State highway in King County, Washington, US
State Route 181 (SR 181, named the Valley Highway) is a 6.05-mile-long (9.74 km) state highway serving King County in the U.S. state of Washington. The highway, travelling north parallel to the Green River, begins at SR 516 in Kent and ends at an interchange with Interstate 405 (I-405) in Tukwila. The highway primarily serves as an alternate route to the SR 167 freeway, which travels east parallel to SR 181.
The original route, between Auburn and Rainier Valley in Seattle, was originally established in 1931 as a branch of Primary State Highway 1 (PSH 1) and in 1937 as Secondary State Highway 5M (SSH 5M). SSH 5M was renumbered to SSH 2M in 1959 and became SR 181 after the 1964 highway renumbering. SR 181 was shortened twice in the 1970s from Seattle to Tukwila and once more in 1991 from Auburn to Kent to form its present route, no longer connected to parent route SR 18.
Route description
SR 181 begins as the Valley Highway at an intersection with SR 516 west of Downtown Kent and an interchange between SR 516 and SR 167. The highway travels north and parallels the Green River and a pedestrian and bicycle trail to the west and the Interurban Trail to the east into Tukwila. SR 181 begins to parallel a BNSF and Union Pacific rail line to the east as it serves Tukwila Station. The highway ends at a partial cloverleaf interchange with I-405, crossing over the Green River shortly before its northern terminus.
“Washington State Route 181” enters the record as state highway in King County, Washington, US. Crown Archives preserves that source wording while asking what Washington, State and Route can confirm, complicate or overturn.
Why this record matters
“Washington State Route 181” is worth following because a concise public description often conceals a longer documentary argument. Here, Washington, State and Route provides the most credible route into that argument.
Maps, plans, fabric surveys and administrative records can establish how the site’s name, extent and function changed over time. The source revision retrieved here is dated Dec 15, 2025. The linked authority identifier is Q835786. VIAF identifies the subject as 315531266. 2 of 2 selected statements include explicit references; 0 carry qualifiers and 0 use preferred rank. The first chronological checks are 1931, 1937, 1959 and 1964.
A single description cannot reconcile every naming convention, rebuilding phase or administrative transfer associated with a place. The lead is largely declarative, so disagreement and counter-evidence require a deliberate search beyond the opening account. Authority statements aid reconciliation but still require their own references, qualifiers and ranks to be checked.
How to read it
Treat names, boundaries and functions as historically changeable. Maps, plans, inventories and administrative records can clarify what the place meant at different dates.
- Historic place names
- Jurisdictional context
- Routes into maps and plans
Contemporary maps, plans, listed-building records, estate papers and the responsible local or national archive.
Three-step research path
- Establish the record: confirm the title “Washington State Route 181”, its source revision and the description used here.
- Expand the search: follow Washington State Route 181 primary sources, Washington State Route 181 archive and Washington research across catalogues and specialist indexes.
- Test the account: compare the strongest cited source with the responsible institution’s current record and note any disagreement.
Questions for further research
- Which source most directly establishes the central claim about “Washington State Route 181”?
- What physical evidence or contemporary plan supports the description?
- Which earlier names or jurisdictions may reveal additional records?
Search terms from this dossier
This entry incorporates text from “Washington State Route 181” on English Wikipedia. Contributors are listed in the page history. Text is available under the Creative Commons Attribution-ShareAlike 4.0 License. Selected authority identifiers and statements are retrieved from Wikidata under CC0; their references and qualifiers remain part of the verification path.