Jamul Mountains-June 2015

By Tom Oberbauer, Vice President CNPS-San Diego

Jamul Mountain

The Jamul Mountains are not as well recognized as some of their nearby neighbors. They are over-shadowed by Otay Mountain at 3,500 feet and San Miguel Mountain at 2,567 feet since they top out at 2,059 feet at the highest point. The Jamul Mountain stand between SR-94 as it passes through the southern part of Jamul, and Proctor Valley.  Proctor Valley is notorious for the strange events that are purported to have occurred there: Proctor Valley monster and two headed cows; remnants of rumors from my youth growing up in the vicinity. Like San Miguel and Otay Mountains, the Jamul Mountains are composed of metavolcanic rock. This is volcanic rock that was deposited as part of a group of very tall mountains like the Andes, but in an island arc off the west coast of North America 106-108 million years ago (Kimbrough, 2014). Since I last climbed the Jamul Mountains in the late 1970’s, many things have changed including the fact that a large part of the surrounding land has been preserved, a steel barrier has been constructed to prevent OHV and trucks from driving cross-country over the slopes, and major fires have occurred. 

Looking across Proctor Valley at San Miguel Mountain

I set out on an overcast morning, overcast where I live, but clear and sunny by the time I reached Proctor Valley.  The temperature of the day was predicted to be in the mid 90’s. I drove down Proctor Valley Road and could see that some things have not changed, especially the washboard surface and the debris from target shooting along the side of the road. I parked my vehicle near a lone Eucalyptus tree and set off toward the peak.

The trail up the mountain is an old vehicle track. It first drops down into a valley with a grove of Eucalyptus trees. At that time, there was a breeze and the temperature was already climbing in the bright, hazy sun. A western lark sparrow produced its ruffly, buzzy song from a Eucalyptus tree on the edge of a grassy patch.  Deinandra fasciculata (Fascicled Tarplant) was in good flower on the clay areas. A mockingbird and Cassin’s kingbirds were calling from Eucalyptus trees as they flew from the upper branches. Across the road from where I parked, Adenostoma fasciculatum (Chamise) was dominant, but on the south and west facing slopes, Coastal sage scrub with Artemisia californica (California sagebrush) and Malosma laurina (Laurel Sumac) were the dominants. 

The fact that Chamise grows in Proctor Valley has always fascinated me. It seems overall like a relatively dry area with maybe 13 or 14 inches of rain a year since it is in the rain shadow of San Miguel Mountain and it is very hot in the summer. I would expect that the vegetation would all be Coastal sage scrub but here is Chamise. The soil may have a major part in the explanation why it is there.  

The temperature continued to rise in the absence of a breeze of any kind as I climbed up the east side of the valley. Rhamnus crocea (Redberry) was recognizable with small, shiny dark green leaves in the glaring light.  The old road was very steep as it crossed a grassy clay soil slope. Lark sparrows were again visible with their white tipped tail feathers. Deer tracks were evident in the fine texture soil. Shiny black Phainopeplas flew nearby like large butterflies creating their weird sounding song that is usually only audible from a short distance.

San Miguel became more visible to the west with the telecommunication towers visible. In the early morning, funnel spider webs were still covered with dew, glistening in the sun, but any trace of overnight condensation was evaporating rapidly. The south facing slope was covered with Bahiopsis laciniata (San Diego Sunflower), Salvia munzii (Munz’s Sage), Malosma laurina, Isocoma menziesii (Spreading Goldenbush) and Artemisia californica. The pathway up the mountain alternated between chipped and broken rock, a gravelly surface of 10 mm. sized pebbles, and reddish clay.
At the bottom of the valley, the surrounding land had the appearance of wilderness because no man-made structures were visible except for the towers on San Miguel Mountain. Farther up on the climb, urbanization became more visible. Sounds carried in the still air.  Cars traveling down Proctor Valley Road could be clearly heard rattling along the washboard surface. Meadowlarks were calling from the grassy areas and it was revealed that these mountains lie in the approach for Lindbergh Field air traffic. At certain times of the day numerous passenger airlines could be seen and heard overhead. In fact, the Google Earth image for the mountain included a large passenger jet passing over the mountains.

Farther up, the trail becomes less defined. Porophyllum gracile (Odora) appeared on the pathway. Its name indicates that it has a strong scent which may be hated or liked by people depending on their scent detection experience. To me, if you crush it between your fingers it has a different odor than the smell as it persists on one’s skin, a little like hot-dogs to me. A barely perceptible east breeze could now occasionally be felt and El Cajon Mountain was clearly visible in the hot haze. Deinandra fasciculatum, Salvia munzii, Adenostoma fasciculatum and Chorizanthe fimbriata (Turkish Rugging) were all in flower. Salvia munzii has an odor that is more aligned with Salvia mellifera (Black Sage) though its overall appearance is that of a reduced size Salvia clevelandii (Cleveland Sage).

At the top of one of the crests, I encountered one of the first Lepechinia ganderi (Gander Pitcher-sage) shrubs. The large greenish, brownish triangular leaves were unmistakable as was the old musty minty Vick’s VapoRub scent. At first at this elevation, none were still in flower. Chamaebatia australis (Southern Mountain Misery) was also growing on the north-slope with Ceanothus tomentosus (Ramona Ceanothus) and Arctostaphylos otayensis (Otay Manzanita) as well. These were all species that grow on Otay Mountain and San Miguel Mountain. Eriodictyon trichocalyx (Felt-leaf Yerba Santa) was growing there as well as Ceanothus crassifolius (Thick-leaf Ceanothus). On a side ridge near this high hill, plants included Salvia clevelandii, Pickeringia montana (Chaparral Pea) a large shrub with spines, and more Chamaebatia australis and Arctostaphylos otayensis. Calochortus weedii (Weed’s Mariposa Lily) was in full flower here as well.

Weed's Mariposa Lily (Calochortus weedii)

Nearby on the south slope, Salvia munzii still persisted and the beautiful Delphinium cardinale (Scarlet Larkspur) to a meter tall grew in a cluster in one location.

There are times when one looks at the extremely steep trail ahead and thinks twice about going forward.  It is steep enough and the gravel loose enough that a misstep could send one tumbling down the slope.  On this climb, there were a number of these situations including the last part to the top. 

There are actually three peaks either just above or just under 2,000 feet in elevation. One was the hill west of the actual peak at over 1,900 feet, steeply separated by a saddle that is 200 feet lower in elevation from the high part itself. Another, the third one, is located to the south a mile and a half away. I could see it with some oaks on the north-slope. At about 10:30 am, the air patterns changed and a breeze from the west picked up; however, it was very warm by that time as well.

I made it to the top where someone had placed a metal stake that had been wrapped with a couple of deflated metallic mylar balloons. A relatively small yellow and black swallowtail butterfly was present, maybe a small form of Anise swallowtail, and a Pale swallowtail, were hill-topping there. A large red dragonfly darter was also there. While I stood there, a large black swallowtail flew in and then flew off. I did not get a good look at it but it gave the impression of a small bat. I wondered if it could have been a Black Witch moth that feeds on acacia, but it seemed more like a swallowtail. It might have been a pipevine butterfly since they are mostly black. 

I sat down to eat lunch. The rocks were hot, I could feel the heat passing through my pants.  I wore gloves and I could feel the heat of the rocks through the surface when I placed my hands on them to raise myself. It was probably 95 degrees. The wind from the west had become quite warm.

I searched for Clinopodium chandleri (San Miguel Savory) where I had seen it before, and Calochortus dunnii (Dunn’s Mariposa Lily) which others had seen there before. I found slender Calochortus fruits on the peak top that could have been the Calochortus dunnii. The Calochortus weedii has more robust fruits.

Scarlet Larkspur (Delphinium cardinale)

It seemed drier here than it had been on the other peaks that I had climbed recently including Syquan, Lawson and Barber Mountain. When I had been on San Miguel, it was drier on the east side than the West side. The rain that fell in May, only 3 weeks before, was somewhat spotty and the East side of San Miguel was drier, so it stands to reason that the Jamul Mountains, just to the east of that, might be drier too. However, the Lepechinia was in pretty good flower on the upper slopes of the Mountain and the Salvia munzii and Salvia clevelandii were in flower higher up on the mountain. 

I gradually worked my way back down. The drop from the peak to the hill to its west was very steep and climbing back up to the west over the next knoll was just as steep. I drank a lot of water, about ¾ gallon, on the mountain. By the time I walked all the way back down, it was still hot. I rewarded myself with two bottles of Gatorade in the car.

The Jamul Mountains is a very interesting place that is probably better visited in May. With their soils derived from Metavolcanic rock, they are another piece of the unusual soil type puzzle.

Photos by the author

Kimbrough, D. L. 2014. Santiago Peak volcanics: early Cretaceous arc volcanism of the Western Peninsular Ranges batholith, Southern California. In:  D.M. Morton, F. K. Miller eds.  Peninsular Range Batholith, Baja California and Southern California. Geological Society of America Memoirs 211:345-363.