{{short description|Highway in California}} {{Use American English|date=March 2025}} {{Use mdy dates|date=January 2025}} {{Infobox road |state=CA |type=SR |route=175 |map_notes=Map of western California with SR 175 highlighted in red |section=475 |length_mi=37.89 |length_round=2 |length_ref=<ref name="bridgelog" /> |restrictions=No vehicles longer than {{convert|39|ft|m|abbr=on}} in length between Hopland and Lakeport<ref name="truckhistory"/> |direction_a=West |terminus_a={{jct|state=CA|US|101}} at Hopland |junction={{jct|state=CA|SR|29}} from near Lakeport to near Kelseyville |direction_b=East |terminus_b={{jct|state=CA|SR|29}} at Middletown |counties=Mendocino, Lake |previous_type=SR |previous_route=174 |next_type=SR |next_route=176 }} '''State Route 175''' ('''SR 175''') is a state highway in the U.S. state of California that runs through the Mayacamas Mountains, connecting U.S. Route 101 in Hopland in Mendocino County with State Route 29 in Middletown in Lake County.
==Route description== SR 175 connects U.S. Route 101 at Hopland to State Route 29 near Lakeport through the Mayacamas Mountains. From there it joins SR 29 until Kelseyville, where it loops out until meeting SR 29 again at its end at Middletown. The section between Hopland and Lakeport is also known locally as the "Hopland Grade", or "Hopland Pass."
Except for the portion on SR 29, SR 175 is not part of the National Highway System,<ref name=fhwa-nhs>{{FHWA NHS map|region=californianorth|accessdate=September 17, 2017}}</ref> a network of highways that are considered essential to the country's economy, defense, and mobility by the Federal Highway Administration.<ref name=NHS-FHWA>{{FHWA NHS}}</ref>
==History== Originally constructed in the early 1920s, it is one of the steepest and most difficult to drive of any California state highway. Until recently it was called the "crookedest road in California".{{citation needed|date=October 2018}} Vehicles more than {{convert|39|ft|m}} in length are banned from the Hopland Grade, due to its many tight hairpin turns and curves.<ref name="truckhistory">{{cite web | url=http://www.dot.ca.gov/trafficops/trucks/restrict-hist-175.html| archive-url=https://web.archive.org/web/20161223133343/http://www.dot.ca.gov/trafficops/trucks/restrict-hist-175.html| url-status=dead| archive-date=December 23, 2016| title=Special Route Restriction History - Route 175 | publisher=Caltrans | access-date=2018-10-13}}</ref> {{Clear}}
==Major intersections== {{CAinttop|post_ref=<br><ref name=trucklist /><ref name=bridgelog>{{Caltrans bridgelog|date=July 2007}}</ref><ref>California Department of Transportation, [https://traffic-counts.dot.ca.gov/ All Traffic Volumes on CSHS], 2005 and 2006</ref> }} {{CAint |county=Mendocino |county_note=MEN 0.00-9.85 |location=Hopland |postmile=0.00 |road={{Jct|state=CA|US|101|city1=Ukiah|city2=Santa Rosa}} |notes=West end of SR 175 }} {{CAint |county=Lake |cspan=3 |county_note=LAK 0.00-28.04 |location=none |type=concur |postmile=R8.19 |line=yes |postmile2=R40.14<ref group="N" name="SR 29">Indicates that the postmile represents the distance along SR 29 rather than SR 175.</ref> |road={{jct|state=CA|SR|29|dir1=north|city1=Lakeport|road|South Main Street}} |notes=West end of SR 29 overlap }} {{CAint |location=none |type=concur |postmile=31.05<ref group="N" name="SR 29"/> |line=yes |postmile2=8.25 |road={{jct|state=CA|SR|29|dir1=south|city1=Lower Lake}} |notes=East end of SR 29 overlap }} {{CAint |location=Middletown |postmile=28.04 |road={{jct|state=CA|SR|29|name1=Calistoga Road|city1=Lower Lake|city2=Calistoga|road|Main Street}} |notes=East end of SR 175 }} {{Jctbtm|keys=concur}} {{reflist|group="N"}}
==See also== *{{portal-inline|California Roads}}
==References== {{Reflist|30em}}
==External links== {{Attached KML|display=inline,title}} {{commons category}} {{CASR external links|SR|175}} *[http://www.aaroads.com/california/ca-175.html California @ AARoads.com - State Route 175] *[http://www.cahighways.org/169-176.html#175 California Highways: SR 175]
State Route 175 175 State Route 175 Category:Mayacamas Mountains