Illinois Route 170
state highway in Linngston and LaSalle counites in Illinois, United States
Illinois Route 170 is a north–south state road in north-central Illinois. It runs from Illinois Route 23 well north of Pontiac to U.S. Route 6 in Seneca. This is a distance of 25.00 miles (40.23 km).
Route description
Illinois 170 is a rural, two-lane surface road for its entire length. The road crosses Illinois River via a four-span truss bridge. As of May 5, 2006, the Illinois Department of Transportation is looking to replace the 74-year-old bridge. The old bridge was imploded on November 18, 2010.
History
SBI Route 160 originally ran from Red Bud to Sparta; this became Illinois Route 154 in 1937. In 1946, it replaced Illinois Route 186 (previously Illinois Route 70A) from Seneca south to Illinois Route 17 near Budd. In 1995 Illinois 170 was extended further south to Illinois 23.
This brief starts where responsible research should: with the source description of “Illinois Route 170” as state highway in Linngston and LaSalle counites in Illinois, United States. Everything that follows is an evidence route, not borrowed authority.
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The subject matters to the general reference register because the source frames it as state highway in Linngston and LaSalle counites in Illinois, United States. Its deeper value depends on whether names, dates, institutions and citations support that framing.
Vocabulary and entity names are the principal evidence signals here, because they determine the precision of every later search. The source revision retrieved here is dated Sep 23, 2026. The linked authority identifier is Q1057512. Authority coordinates are 41.156, -88.645. 2 of 2 selected statements include explicit references; 0 carry qualifiers and 0 use preferred rank. The first chronological checks are 2006, 2010, 1937 and 1946.
A concise general-reference account can conceal disagreements about scope, terminology or the weight assigned to individual sources. 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.
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This entry incorporates text from “Illinois Route 170” 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.