California State Route 12

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State Route 12

SR 12 highlighted in red
Route information
Maintained by Caltrans
Length140.64 mi[1] (226.34 km)
California Scenic State.svg Valley of the Moon Highway between Santa Rosa and Agua Caliente[3]
Major junctions
West end SR 116 in Sebastopol
Major intersections
East end SR 49 in San Andreas
CountryUnited States
CountiesSonoma, Napa, Solano, Sacramento, San Joaquin, Calaveras
Highway system
SR 11 SR 13

State Route 12 (SR 12) is a state highway in the U.S. state of California that travels in an east–west direction from State Route 116 in Sebastopol in Sonoma County to State Route 49 just north of San Andreas in Calaveras County. The route connects the Sonoma and Napa valleys with the Sacramento–San Joaquin River Delta and the Sierra Foothills. It is constructed to freeway standards from the Fulton Road/South Wright Road stoplight in Santa Rosa, to its partial interchange with Farmers Lane (also in Santa Rosa).

Route description

SR 12 runs along Broadway in Sonoma
SR 12/SR 113 roundabout
SR 12 runs along Kettleman Lane in Lodi
SR 12 between Lodi and Jackson

There are six segments that are overlaps with other highways: in the Napa and Sonoma valleys with SR 121, in the southern Napa Valley with SR 29, a short overlap with I-80 at Cordelia Junction in Fairfield, another short overlap with SR 99 in Lodi, and overlaps with SR 88 and SR 26 in the Sierra foothills. The highway is mainly two lane rural highway, with the exception of short segments in Santa Rosa and Fairfield/Suisun City, the overlaps with I-80 and SR 99, and segments within developed areas, such as Santa Rosa and Lodi.[4][5]

SR 12 begins in the west at its junction with SR 116 in Sebastopol. After passing east through Santa Rosa on a mix of freeway, surface street, and expressway, it turns south into the Sonoma Valley, passing the Jack London State Historic Park at Glen Ellen. It winds through Sonoma on surface streets, where the historic Vallejo Estate and Sonoma Mission, both part of the Sonoma State Historic Park, are.[4][5]

South of Sonoma, SR 12 turns east, joining SR 121 for nearly nine miles, then turns south briefly as it leaves SR 121 and joins the four-lane expressway SR 29 to cross the Napa River. Four miles after joining SR 29 it splits off towards the east on Jameson Canyon Road; this section is also the 1928 re-alignment of the Lincoln Highway, the first road across America. After a brief merge with Interstate 80, SR 12 branches off to the east as an expressway through Fairfield and Suisun City. East of Suisun it becomes two lanes again and crosses south of Travis Air Force Base, through rolling fields with numerous wind turbines. Just past Braid's Bridge is the Western Railway Museum. At Rio Vista, SR 12 crosses the Helen Madere Memorial Bridge over the Sacramento River, entering the California Delta.[4][5]

This stretch of the river has twice been the site of much-publicized inland excursions by humpback whales, presumably veering off course while making their annual migrations along the Pacific coast. In 1985 Humphrey the whale swam about as far as the Rio Vista Bridge. In 2007 a humpback mother and calf dubbed Delta and Dawn circled for several days just upstream of the bridge, seemingly reluctant to pass under it again after having spent the previous three or four weeks upriver near Sacramento.

From the Sacramento River to the junction with Interstate 5, SR 12 crosses several of the waterways of the California Delta and the low-lying fields between them. Through Lodi it becomes a wide four-lane business route. After another brief merger with another freeway, this time SR 99, SR 12 heads east into the Sierra foothills (with shared segments with SR 88 and SR 26) before ending at the junction with SR 49 just north of San Andreas.[4][5]

SR 12 is part of the California Freeway and Expressway System,[6] and in Sebastopol, from US 101 to Sonoma, and from I-80 to SR 88 is part of the National Highway System,[7] a network of highways that are considered essential to the country's economy, defense, and mobility by the Federal Highway Administration.[8] SR 12 is eligible to be included in the State Scenic Highway System;[9] however, it is only designated as a scenic highway from its intersection with Danielli Avenue east of Santa Rosa to its junction with London Way near Agua Caliente,[10] meaning that it is a substantial section of highway passing through a "memorable landscape" with no "visual intrusions", where the potential designation has gained popular favor with the community.[11]

SR 12 has been designated by various state laws and through local usage as the Valley of the Moon Scenic Route (the portion running through Sonoma County, though the first sign with this name is at the intersection of Farmers Lane and Fourth Street in Santa Rosa);[12] Luther Burbank Memorial Highway from Santa Rosa to Sebastopol (after botanist Luther Burbank).[13] SR 12 is also known as Sonoma Highway between Santa Rosa and the west side of the city of Sonoma; Broadway between Sonoma Plaza and its junction with SR 121 in Schellville; Carneros Highway for the length of its concurrency with 121 between Schellville and its junction and the north end of its concurrency with SR 29 near Napa;[14] Jameson Canyon Road from where its concurrency with SR 29 ends in American Canyon to its junction with I-80 in Cordelia; and Rio Vista Highway from I-80 to SR 160 east of Rio Vista,[15][16] and informally as "Blood Alley" from Lodi to Fairfield.[17] The segment through Lodi to the overlap with SR 99 is on Kettleman Lane.[4]


Before the 1964 renumbering, this route was signed as Sign Route 12 for most of its length. However, SR 12 was designated as Legislative Route 51 (LR 51) from SR 116 to SR 121 before the 1964 renumbering. Portions of the route from SR 29 to I-80 ran concurrently with State Route 29 or with State Route 37; this was also LR 8 and a former routing of US 40. The portion from I-80 to then-US 99 was designated as LR 53 in 1919; from US 99 to SR 49, it was designated as LR 24.[18]

In 1976, the discontinuity resulting from the concurrency with State Route 84 was removed.[18]

In January 1996, photographer Charles O'Rear pulled off the highway east of Schellville near the NapaSonoma county line to photograph the lush hillside by the road. The image became known as Bliss and was used as the default computer wallpaper of Microsoft's Windows XP operating system.[19]

Future extension

Plans call for a western extension of its western terminus to State Route 1 near Bodega Bay.[20] Plans also called for Route 12 to be built as a freeway from Farmers Lane to Melita Road, in Santa Rosa; however, as of 2014, this project was delayed due to community opposition.[21]

Major intersections

Except where prefixed with a letter, postmiles were measured on the road as it was in 1964, based on the alignment that existed at the time, and do not necessarily reflect current mileage. R reflects a realignment in the route since then, M indicates a second realignment, L refers to an overlap due to a correction or change, and T indicates postmiles classified as temporary (for a full list of prefixes, see California postmile § Official postmile definitions).[22] Segments that remain unconstructed or have been relinquished to local control may be omitted. The numbers reset at county lines; the start and end postmiles in each county are given in the county column.

SON 9.12-41.36
Sebastopol9.12Bodega Avenue – Bodega BayContinuation beyond SR 116
9.12 SR 116 (Petaluma Avenue, Main Street) – San Francisco, JennerWest end of SR 12
Santa RosaR12.94Fulton Road, Wright Road
West end of freeway
R14.455Stony Point Road
R15.306Dutton Avenue
R16.047A US 101 – San Francisco, EurekaSigned as exits 7A (south) and 7B (north) westbound; US 101 exit 488B
R16.637BSouth E Street – Downtown Santa RosaSigned as exit 7C westbound
East end of freeway
T17.53Farmers Lane
7.44[N 1]

SR 121 south (Fremont Drive) – Petaluma, San Francisco
West end of SR 121 overlap
NAP 0.00-3.31
NapaR4.47[N 1]
R8.66[N 2]

SR 29 north / SR 121 north – Napa, Calistoga
East end of SR 121 overlap; west end of SR 29 overlap
R6.20[N 2] SR 221 / Soscol Ferry Road – Downtown Napa, Lake BerryessaSouthern terminus of SR 221
4.71[N 2]

SR 29 south / Airport Boulevard – Vallejo, Napa County Airport
East end of SR 29 overlap
SOL 0.00-26.41

Red Top Road to I-80 west – San Francisco
No left turn from SR 12 west
R11.98[N 3]

I-80 west – San Francisco
West end of I-80 overlap; westbound exit and eastbound entrance; I-80 west exit 39B; no entrance from I-80 east
West end of freeway on I-80
12.74[N 3]40Green Valley RoadWestbound exit is part of exit 41
12.84[N 3]40
I-680 south – Benicia, Martinez, San Jose
I-680 north exits 71A-B
13.49[N 3]41Suisun Valley Road, Pittman Road
15.82[N 3]

I-80 east – Sacramento
East end of I-80 overlap; eastbound exit and westbound entrance; I-80 west exit 43

Chadbourne Road to I-80 east – Fairfield Auto Mall, Sacramento
East end of freeway
Suisun CityR4.4758AWebster Street, Jackson Street – FairfieldInterchange
R4.5758BMain Street – Suisun City Business DistrictInterchange
SR 113 north / Birds Landing Road – Dixon, Birds Landing, Collinsville
Southern terminus of SR 113
Rio Vista26.28 SR 84 / Front Street – Rio Vista, Ryer IslandInterchange; southern terminus of SR 84 northern segment
Solano–Sacramento county lineRio Vista city limit Rio Vista Bridge over the Sacramento River
SAC 0.00-6.20
0.57 SR 160 (River Road) – Isleton, Sacramento, Antioch
San Joaquin
SJ 0.00-27.64
10.17 I-5 – Sacramento, Stockton, Los AngelesInterchange; I-5 exit 485
10.30 CR J8 (Thornton Road)
Lodi15.16 CR J10 (Lower Sacramento Road) – Woodbridge
16.93 CR J3 (Hutchins Street)Northern terminus of CR J3
SR 99 Bus. (Cherokee Lane) – Central District
Former US 50 / US 99
29.50[N 4]

SR 99 south / Kettleman Lane – Fresno, Los Angeles
Interchange; west end of SR 99 overlap; SR 99 exit 264B
West end of freeway on SR 99
East end of freeway on SR 99
30.97[N 4]

SR 99 north / Victor Road – Sacramento, Central Lodi
Interchange; east end of SR 99 overlap; SR 99 exit 266
L12.24[N 5]

SR 88 west / Victor Road – Stockton
West end of SR 88 overlap
13.60[N 5] CR J5 (Jack Tone Road)West end of CR J5 overlap
14.08[N 5] CR J5 (Elliott Road) / Tully RoadEast end of CR J5 overlap
Clements19.17[N 5]

SR 88 east – Ione, Jackson, Lake Tahoe
East end of SR 88 overlap
CAL 0.00-18.20
Valley Springs9.93
SR 26 west / Laurel Street – Linden, Campo Seco, Pardee Reservoir, Lake Amador
West end of SR 26 overlap
SR 26 east / Toyon Circle – Mokelumne Hill
East end of SR 26 overlap
18.20 SR 49 – Mokelumne Hill, San AndreasEast end of SR 12
1.000 mi = 1.609 km; 1.000 km = 0.621 mi
  1. ^ a b Indicates that the postmile represents the distance along SR 121 rather than SR 12.
  2. ^ a b c Indicates that the postmile represents the distance along SR 29 rather than SR 12.
  3. ^ a b c d e Indicates that the postmile represents the distance along I-80 rather than SR 12.
  4. ^ a b Indicates that the postmile represents the distance along SR 99 rather than SR 12.
  5. ^ a b c d Indicates that the postmile represents the distance along SR 88 rather than SR 12.


  1. ^ a b California Department of Transportation (July 2007). "Log of Bridges on State Highways". Sacramento: California Department of Transportation.
  2. ^ "California Highways: State Route 12". Retrieved November 28, 2011.
  3. ^ California Department of Transportation (August 2019). "Officially Designated State Scenic Highways and Historic Parkways" (XLSX). Sacramento: California Department of Transportation. Retrieved March 27, 2019.
  4. ^ a b c d e California State Automobile Association map Gold Country, 7-05 edition
  5. ^ a b c d California State Automobile Association map San Francisco Bay, 1-09 edition
  6. ^ "Article 2 of Chapter 2 of Division 1". California Streets and Highways Code. Sacramento: California Office of Legislative Counsel. Retrieved February 6, 2019.
  7. ^ Federal Highway Administration (March 25, 2015). National Highway System: California (North) (PDF) (Map). Scale not given. Washington, DC: Federal Highway Administration. Retrieved October 20, 2017.
  8. ^ Natzke, Stefan; Neathery, Mike & Adderly, Kevin (June 20, 2012). "What is the National Highway System?". National Highway System. Washington, DC: Federal Highway Administration. Retrieved July 1, 2012.
  9. ^ "Article 2.5 of Chapter 2 of Division 1". California Streets & Highways Code. Sacramento: California Office of Legislative Counsel. Retrieved February 6, 2019.
  10. ^ California Department of Transportation (August 2019). "Officially Designated State Scenic Highways and Historic Parkways" (XLSX). Sacramento: California Department of Transportation. Retrieved October 20, 2017.
  11. ^ California Department of Transportation (2012). Scenic Highway Guidelines (PDF). Sacramento: California Department of Transportation. p. 5. Retrieved June 8, 2017.
  12. ^ "California Highways: Routes 009-016 to Individual Page Detour". Archived from the original on July 9, 2016. Retrieved March 21, 2006.
  13. ^ 2007 Named Freeways, Highways, Structures and Other Appurtenances in California (PDF). Caltrans. pp. 122–123. Retrieved March 28, 2007.
  14. ^ "California Highways: Routes 121-128 to Individual Page Detour". Archived from the original on May 22, 2016. Retrieved September 28, 2012.
  15. ^ California Highway Patrol: CADWEB[dead link] Name from CHP traffic reports. Archived on Google cache on September 24, 2007. Accessed on 2007-10-01.
  16. ^ Google (October 1, 2007). "map of Route 12 showing Rio Vista Highway name from I-80 to SR 160" (Map). Google Maps. Google. Retrieved October 1, 2007.
  17. ^ Deaths on Highway 12. San Joaquin Record All Eyes on Blood Alley. Accessed on May 12, 2008.
  18. ^ a b "California Highways ( Routes 9 through 16". Retrieved November 28, 2011.
  19. ^ Taylor, Victoria (April 12, 2014). "The story behind the famous Windows XP 'Bliss' wallpaper". New York Daily News. Retrieved April 12, 2014.
  20. ^ Democrat: County OKs bypass around Forestville Archived March 7, 2012, at the Wayback Machine, accessed June 15, 2010
  21. ^ Brown, Matt (2014-08-21). "Southeast Greenway boosters cheer decision on highway extension". Santa Rosa Press Democrat. Retrieved 2020-03-12.
  22. ^ a b California Department of Transportation. "State Truck Route List". Sacramento: California Department of Transportation. Archived from the original (XLS file) on June 30, 2015. Retrieved June 30, 2015.
  23. ^ California Department of Transportation, All Traffic Volumes on CSHS, 2005 and 2006
  24. ^ California Department of Transportation, California Numbered Exit Uniform System, State Route 12 Freeway Interchanges, Interstate 80 Freeway Interchanges, Retrieved on February 5, 2009.

External links