Chumash Rock


Rock formation northwest of the Chumash Trail.
Rock Formation Northwest of the Chumash Trail


Practically any objective can make a good excuse for an adventure. Each time up or down the Chumash Trail, I pondered the prominent rock formation northwest of the trail, and wondered what I might find there.


My first thought was to find a direct route across the deep canyon that parallels the Chumash Trail. Recons from a couple of points on the trail revealed that the this was a bad idea. Sections of the canyon that looked passable from above were incised, with crumbling, near-vertical walls. A Plan B was required.


A look at a topo map suggested it might be possible to access the ridge on which the formation was located from Las Llajas Canyon. An advantage of this approach was that, if it worked, it would be part of a loop. A cool January morning, I decided to give it a go.


From Las Llajas Canyon, an old overgrown roadbed led up a side canyon to a point where there was no obvious route. The canyon bottom did not look promising, and steep slopes bounded both sides of the canyon. After scrambling several hundred feet up a south-facing slope, I found a deer trail that seemed headed in the general direction I wanted to go. This game trail was the key. Its route reflected the cumulative experience of deer in dealing with the terrain issues I faced. It turned out to be remarkably efficient, and appeared to represent the path of least energy needed to reach the main ridge. That is, if you’re a deer. At one point I was forced to backtrack and climb above the trail when it crossed a steep, exposed slope better suited to those with four legs and cervid hooves.


Once up on the main ridge, it didn’t take long to reach the rock formation. According to the Dibblee geological map of the area, the formation is positioned on the south branch of the Simi Fault. The steeply inclined beds of river cobble seen in this photo might have been deposited as part of a fan delta some 60 million years ago. This Paleocene age cobble is also encountered at several places along the Chumash Trail.


Near the summit of the formation some chiseled inscriptions  were found. They were very weathered. The most prominent might be either a “93” or “33” over the top of a “W,” and another is perhaps a “DH.” It’s hard to tell.


Of the three high points comprising the formation, I scrambled to the top of two. The eastern-most summit (on the far right when viewed from the Chumash Trail) is wholly comprised of cobble and looked like an accident waiting to happen. Here’s a photo from near the summit of the formation, looking back down the ridge.


As I climbed down from the summit to a saddle northeast of the rock formation, I spooked a deer and it bounded into a brush filled gully. Continuing up the ridge, it eventually intersected Rocky Peak Rd. at its high point near some bivalve fossil beds. According to the Dibblee map, these are much younger than the rock formation’s river cobble, and may have been deposited in shallow marine conditions or lagoons a couple million years ago.


At Rocky Peak Rd. I had the option of returning via Las Llajas Canyon, but opted to complete the approximately 8 mile route via the Chumash Trail. This Google Earth image  shows most of the route. (Photographs from hike & run on January 29, 2006.)

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