What is the Historic Ridge Route?
The Ridge Route Highway is that section of road that winds over the San Gabriel and Liebre Mountains between Castaic Junction on the south (where I-5 junctions with Hwy 126 to Ventura) and extends to the bottom of Grapevine Grade on the north where I-5 enters the great San Joaquin Valley.
The “Grapevine” is the 6 1/2 mile segment of the Ridge Route that extends from Fort Tejon to the bottom of Grapevine Grade. Many people erroneously believe that the “Grapevine” got its name because the original 1915 highway had a series of “switchbacks” which allowed early vehicles to gain elevation as they climbed the grade heading from Bakersfield toward Los Angeles. The serpentine path resembled a giant grapevine. Although this observation was true, the name actually came from the fact that early Wagoner’s had to hack their way through thick patches of Cimarron grapevines that inhabited “La Canada de Las Uvas,” Canyon of the Grapes. Traveling the grade today, look for patches of what appears to be ivy on both sides of the canyon near the truck runaway escape ramps. What you see are descendant vines which date back to the 1800’s.
The news media incorrectly refers to the entire Ridge Route as the Grapevine.
There have been (3) Ridge Route highways. The 1915 highway which is our focus; the 1933 three-lane Ridge Route Alternate Highway identified as US 99 (converted to a 4-lane expressway between 1943 and 1951); and today’s 8-lane I-5 freeway completed in 1970. The Ridge Route Alternate was severed with the construction of Pyramid Dam.