Panoche Road and former CA 180 over the Diablo Range

[Max Rockatansky]

Panoche Road is an approximately 64-mile-long rural highway located in the coast ranges of central California.  Panoche Road begins at California State Route 25 near Paicines in San Benito County and carries the designation of County Route J1 through the Diablo Range to Little Panoche Road in Panoche Valley.  Panoche Road continues east from Panoche Valley and becomes a dirt highway approaching the ford of Big Panoche Creek.  The dirt segment of this corridor continues into Fresno County passing through the Panoche Hills and Tumey Hills before emerging into San Joaquin Valley at an interchange with Interstate 5.  The remaining 18 miles of Panoche Road east of Interstate 5 to California State Route 180 near Mendota are comprised of conventional paved highway. 

Panoche Pass was a well-established crossing of the Diablo Range prior to European contact.  Panoche Road became to come into prominence as the primary highway over the Diablo Range in 1854 following founding of the New Idria Mercury Mine.  The corridor over Panoche Pass would remain the favored route over the Diablo Range to San Joaquin Valley until the Pacheco Pass Highway was rebuilt to State Highway standards in 1923. 

Panoche Road was designated as part of California State Route 180 in August 1934 when the initial run of Sign State Route was announced.  Despite obtaining a Sign Route designation the corridor of Panoche Road was never adopted as State Highway and was only partially modernized during the 1940s.  In 1958 County Route J1 was designated over Panoche Road between California State Route 25 and Little Panoche Road.

In 1959 Legislative Route Number 263 was added to the State Highway System as a planned corridor following the established path of Panoche Road.  Despite being annexed into the legislative definition of California State Route 180 in 1964 the corridor Panoche Road has never been added to the State Highway System.  A 2013 report on traversable routings suggested a new alignment would be needed to extend California State Route 180 west of Interstate 5.

https://www.gribblenation.org/2025/12/panoche-road-and-former-california.html?m=1

[FredAkbar]

I always liked seeing the highway miles sign on I-5N for Panoche Road, Russell Ave, and Little Panoche Road (GSV). It helps to break up the drive into smaller manageable segments, and it's a good midway point between Kettleman City and Santa Nella / CA-152.