In Siskiyou County, SR 3 passes through Callahan, Etna, Greenview, and Fort Jones as it turns northeast to intersect with Interstate 5 in Yreka. At this point, SR 263 continues in the northerly direction towards SR 96; SR 3 turns east to its northern terminus in the incorporated city of Montague.[3][4]
In 2014, SR 3 had an annual average daily traffic (AADT) of 135 at U.S. Forest Service Road, and 10,000 at Moonlit Oaks Avenue, the latter of which was the highest AADT for the highway.[12]
The short piece from SR 36 north to Peanut was added to the state highway system in 1907 as part of the Peanut Road,[14] which became Route 35 in 1917.[15] Route 35 was extended north from Peanut to Route 20 (SR 299) near Douglas City in 1933, and simultaneously a new Route 82 was created, running from Route 3 (I-5) in the Yreka area southwest to Etna and east to Montague.[16][17] The gap between Douglas City and Etna was filled in 1959 with an extension of Route 82 south to Route 20 near Weaverville; at the same time, the portion between Weaverville and Yreka was added to the California Freeway and Expressway System, which identifies the main routes of transportation in the state of California.[18] The State Route 3 designation was applied to the Peanut-Montague roadway in the 1964 renumbering.[19] The overlap with temporary I-5 (along the portion where SR 3 runs concurrently with Interstate 5 today) near Yreka was removed when the new I-5 bypass was built; the legislative definition was updated to reflect this in 1974, soon after the building of the bypass.[20]
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).[1] 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.
123California Department of Transportation. "State Truck Route List". Sacramento: California Department of Transportation. Archived from the original(XLS file) on September 5, 2015. Retrieved June 30, 2015.
123California Road Atlas and Driver's Guide (Map). Thomas Brothers. 2000. p.3,4,11,12,17.
↑"Article 2 of Chapter 2 of Division 1". California Streets and Highways Code. Sacramento: California Office of Legislative Counsel. Retrieved February 6, 2019.
↑Federal Highway Administration (March 25, 2015). National Highway System: California (North)(PDF) (Map). Scale not given. Washington, DC: Federal Highway Administration. Retrieved October 21, 2017.
↑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.
↑California Department of Transportation (2012). Scenic Highway Guidelines(PDF). Sacramento: California Department of Transportation. p.5. Retrieved June 8, 2017.
↑California Department of Transportation (2014). "All Traffic Volumes on CSHS". Sacramento: California Department of Transportation. Retrieved July 29, 2016.
↑Ben Blow, California Highways: A Descriptive Record of Road Development by the State and by Such Counties as Have Paved Highways, 1920 (Archive.org or Internet Archive), p. 112
