Historical Tour of US 99
Castaic Valley
Castaic
El. 1280′
Castaic, formerly a small ranching community, serves as a major truck stop on I-5 today. As it sits at the bottom of the first major mountain grade north of Los Angeles, it is perfectly suited to this task. US 99 followed Ridge Route Road from 1915 – 1933, Castaic Road from 1933 – 1951, and the same alignment as I-5 from 1951 – 1967/70, and lastly I-5 from 1967/70 to present.
In 1933, US 99 was built through Castaic along Castaic Road with three lanes. In 1951, the town was bypassed by the four lane expressway version of US 99. In 1968, I-5 was completed through here and was built atop the old expressway.
Go North on US 99 to Bakersfield
Go South on US 99 to Los Angeles
Return to US 99 Introduction