SR 126 generally follows the Santa Clara River through the valley, passing through the towns of Fillmore and Santa Paula. The freeway portion of the highway, known as the Santa Paula Freeway, begins in Ventura at U.S. Route 101. It proceeds northeast through the city, interchanging with the western end of SR 118 at a grade-separated interchange. SR 126 then passes through areas of agriculture, orchards, and the Saticoy Oil Field to its northeast, continuing through Santa Paula, where it intersects SR 150, and the freeway portion terminates at Hallock Drive. SR 126 continues as a highway thereafter, known as Telegraph Road. This section extends through Fillmore as Ventura Street, where SR 126 meets SR 23. Following this, SR 126 as Telegraph Road encounters the community of Buckhorn, as well as the edge of Piru and the important historical Rancho Camulos.