CSO Hill


CSO Hill was the area in Pico Canyon where most of the California Star Oil Works Company wells were drilled. The area started on the bottom of the creek and then westward high up the mountain.

I found very few oil artifacts in this area. However, there were a lot of wildflowers and ticks to make it interesting.


The front of CSO Hill. View toward the west. The caption for this picture states that it was taken in 1885 and the well in the lower left is probably CSO 32. The bridge was called the "Long Bridge" and was completely destroyed by the April 4, 1893 earthquake and never rebuilt. However, after carefully studying the well locations on a map (and in the field with a GPS) and researching the well data, and looking at the 1897-1900 photo on the historic photos page, this cannot be correct. CSO 32 was spudded in 1903. That well can only be CSO 5, spudded in 1880. The upper three wells on the face of the hill can only be Star 1 (spudded in 1884) on the lower right directly above the building, CSO 21 (spudded in 1893) above to its left, and CSO 15 (spudded in 1888) in the distance between those two wells. The photo also does not show CSO 24, spudded in 1896. That means the photo was taken between 1893 and 1896. Also, the bridge still exists on the 1897-1900 photo. The Long Bridge was built in 1884 for access to the Star 1 well site.

Photo used by permission of the Santa Clarita Valley Historical Society


Nearly the same view in 2008. The road was expanded from its 1885 size and there are more trees blocking the view, so it was difficult to exactly recreate the previous picture.


The complete view of CSO Hill looking west. The two CSO 4 markers are barely visible in the bottom right of the photo. Note the traces of the road zigzaging up the mountain. I took this picture from high up on PCO Hill.


Steam engine over the side of a hill. It is too rusted to see any markings.


Another view of same engine


About a 23-inch diameter crown block pulley. This pulley would be located on the top of the derrick.


Large 38-inch diameter flange with 8 bolts


Side view showing that there are actually two flanges. These were probably on a band wheel shaft with the band wheel bolted between them.


Old barrel


Sucker rod joints for wooden sucker rods


Loop on one end of about a 6-foot long pole


This loop below a well site probably was probably used for a line to the derrick to keep it from blowing down. I could not budge it.


Some jackline hardware


This is probably the base of a jackline support


Baby rattlesnake


Deer at the site of Star 1


There were a lot of wildflowers in bloom. Here is a chia.


Tree (or Bush) Poppy


California poppies


Wild lupine