California State Route 83
state highway in San Bernardino County, California, United States
State Route 83 (SR 83), also or primarily known as Euclid Avenue, is a state highway and city street in the U.S. state of California. Though some maps and signs may mark SR 83 as continuous, control of the highway have been relinquished in piecemeal segments to local jurisdictions, with the goal of decommissioning SR 83 as a state highway. Since June 2024, SR 83 officially runs from the Chino Valley Freeway (State Route 71) at the Chino Hills–Chino border north to the Chino–Ontario border. Euclid Avenue then continues north through Upland to the unincorporated community of San Antonio Heights.
Euclid Avenue passes through several historic districts. The segment of the road between Philadelphia Street in Ontario and 24th Street in Upland is listed on the National Register of Historic Places.
Route description
Route 83 is defined in section 383, subdivision (a), of the California Streets and Highways Code, last amended by the California State Legislature in January 2024, and that the highway is "from Route 71 to Route 10 near the City of Upland". Subdivision (b) of section 383 states that the relinquished former northern segment of Route 83 in Upland is no longer officially part of the state highway system, but the city must still "maintain signs directing motorists to the continuation of Route 83". Subdivisions (c) and (d) of section 383 permit the state to also relinquish control of all or a portion of Route 83 located in the cities of Ontario and Chino respectively. If a full relinquishment occurs under both subdivisions, Route 83 will be removed from the state highway system.
Begin with the source’s own compact description: “California State Route 83” is state highway in San Bernardino County, California, United States. The dossier treats that line as a proposition to test through California, State and Route, not as a finished interpretation.
Why this record matters
The phrase “state highway in San Bernardino County, California, United States” supplies a clear boundary for inquiry. It also exposes the unanswered questions: who defined that boundary, when it became stable and which sources sit outside it.
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 Sep 2, 2026. The linked authority identifier is Q624172. Authority coordinates are 34.150, -117.651. 1 of 1 selected statements include explicit references; 0 carry qualifiers and 0 use preferred rank. The first chronological checks are 2024.
A single description cannot reconcile every naming convention, rebuilding phase or administrative transfer associated with a place. The source lead contains qualifying language; that uncertainty should survive quotation, summary and reuse. 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 “California State Route 83”, its source revision and the description used here.
- Expand the search: follow California State Route 83 primary sources, California State Route 83 archive and California 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 “California State Route 83”?
- What physical evidence or contemporary plan supports the description?
- Which authority defined the place, boundary or structure at the relevant date?
Search terms from this dossier
This entry incorporates text from “California State Route 83” 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.