Ridge Route

The Ridge Route, officially the Castaic–Tejon Route and colloquially known as the Grapevine, was a two-lane highway between Los Angeles County and Kern County, California. Opened in 1915 and paved with concrete between 1917 and 1921, the road was the first paved highway directly linking the Los Angeles Basin with the San Joaquin Valley (southern Central Valley) over the Tejon Pass and the rugged Sierra Pelona Mountains ridge south of Gorman. Much of the old road runs through the Angeles National Forest, and passes many historical landmarks, including the National Forest Inn, Reservoir Summit, Kelly's Half Way Inn, Tumble Inn, and Sandberg's Summit Hotel. North of the forest, the Ridge Route passed through Deadman's Curve before ending at Grapevine.

The road was bypassed by the three-lane Ridge Route Alternate, then U.S. Route 99 (US 99), to handle increased traffic and remove curves; the Alternate in Los Angeles County was completed in 1933, and Kern County line to Grapevine in 1936. The four-lane US 99 was completed in 1953 and replaced by an eight-lane freeway, Interstate 5 (I-5) in 1960-70. The portion of the road in the Angeles National Forest was added to the National Register of Historic Places in 1997, by the efforts of Harrison Scott. Much of the road has been closed by the U.S. Forest Service; other remnants are used by local traffic.