SR 145 travels through the center of the San Joaquin Valley, remaining a rural two-lane road in its entirety. The southern terminus of SR 145 is at I-5 near Coalinga. SR 145 heads northeast as Fresno-Coalinga Road, turning north at the junction with SR 269 in Five Points, where it assumes the designation as Lassen Avenue. After passing through the town of Helm, SR 145 heads northeast as McMullin Grade, before turning north again as South Madera Avenue. SR 145 intersects with SR 180 in the city of Kerman, where it continues north to cross into Madera County. After passing through Ripperdan, SR 145 intersects SR 99 in Madera. From Madera, the route turns east, and ends at SR 41.[2]
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).[6] 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.
^ abCalifornia Department of Transportation (July 2007). "Log of Bridges on State Highways". Sacramento: California Department of Transportation.
^California Road Atlas (Map). Thomas Brothers. 2008.
^"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 (South)(PDF) (Map). Scale not given. Washington, DC: Federal Highway Administration. Retrieved September 25, 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.
^ abCalifornia 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.