This branch line was originally constructed in the 1890s as the Ventura & Ojai Valley RR, and it was purchased by SP within a few years. [Ojai is pronounced OH-hi]. This line branched off the SP Coast Line at Ventura Jct., which is just west of the existing Amtrak platform at Ventura. The line extended north along the Ventura River, through Chrisman, Wedstrom, Ortonville and Nitroshell to Mira Monte. At Mira Monte the line turned east to the end of the line at Ojai. Most customers were citrus growers and other agricultural businesses. The northern portion of the branch was abandoned by 1975; the southern part might have lasted a few years longer. The right-of-way is easily traced today, as much of it has been converted to a bicycle trail, called the "Ojai Valley Trail" and the "Ventura River Trail".

From TO search:

The tracks from Ventura Jct.(MP397.3) to Canet(MP402.6) remained active untill the late 80's. The Nitroshell refinery was the last active industry on the branch(I believe) and closed up shop about '88 or '89. I can remeber seeing half a dozen or so excess tank cars stored in the siding at Ortonville(MP400.8, Shell road)for weeks at a time. I grew up on the other side of the 33 from the Nitroshell refinery. I remeber seeing the local with two GP units several times. I don't remember a whole lot since I was 7 or 8 when they stopped using the line. The tracks still existed up until about 2 years ago. The County bought the R-O-W and turned it into a bike path. There are still a few places where the tracks are still there. The Nitroshell refinery still has some trackage. And the OST yard still has a little bit of track.

Ojai resort was built in 1923.

Hope that helps.