El Cajon Mountain

By Tom Oberbauer, Past President CNPS-San Diego

As one drives east on Interstate 8, between El Cajon and Alpine, a large mountain is to the north. It is notable for the high ridge point that has nearly shear cliffs on two pointed sides. The light-colored granodiorite cliffs are visible from far away. If one drives up the San Diego River in Lakeside traveling to El Monte Park, the mass of the mountain becomes even more visible, dropping directly into the Valley. The true name of this mountain is El Cajon Mountain because of its proximity to El Cajon and El Cajon Valley. El Cajon istranslated to be “the box”. It seems a bit amusing that a mountain would be named box mountain. However, everyone who sees the mountains and those who live near it refer to it as El Capitan. El Capitan or “the captain” is the name of one of the famous landmarks in Yosemite, and its resemblance to that landmark is the reason that this mountain is usually referred to as El Capitan. In fact, El Capitan High School and El Capitan Dam both reflect that local name for the mountain.

The mountain is not really large, being 3,651 feet in elevation, but it is located in the midst of granitic rock domes – massive plutons of rock that are the product of subduction and fractionization of molten material. During the Cretaceous, 145 to 66 million years ago, the sea floor was subducted beneath the north American plate. As the sea floor plate was forced downward beneath the continental crustal mass, it was heated and became molten. The heavier basaltic material stayed low in the molten column but lighter materials, such as quartz and feldspar, bowed upward due to its lighter mass being distilled out of the mix of molten rock, far below the earth’s surface. The lighter molten rock formed large balloon shaped blobs that intruded upward, heating their surroundings but also cooling very slowly, maybe taking millions of years. The slow cooling process allowed for crystals and chunks of orthoclase and plagioclase feldspar within the quartz to grow. Impurities of iron and other minerals also grow into crystals, producing their light gray white or slightly tan rock with flecks of black mica and black tourmaline or shorl.

These large solid balloon-shaped blobs of slowly cooled rock (plutons) stayed beneath the surface until plate tectonic forces raised the crust upward. As the erosive forces of millions of years of rain and weathering occurred, the overlaying surfaces eroded away, the large plutons of hard granitic material were exposed to the surface and even thrust higher upward. Famous plutons include Half Dome and El Capitan in Yosemite.

El Capitan Mountain, or El Cajon Mountain, in San Diego County are also plutons of granitic rock. However, it is only one of the plutons in the area with at least one or two more large granitic domes to the west.

I had an assignment to walk to a population of Brodiaea orcuttii (Orcutt’s Brodiaea) on the mesa located on the part of El Capitan Mountain that forms a nose with 1,500-foot high cliffs on both sides. The plan was to relocate the Brodiaeas and estimate the size of the entire population on the mesa of the mountain. Access to the mesa involves walking from Wildcat Canyon Road north of Lakeside on a 5-mile trail to a junction in saddle of the mountain, and walking another mile down to the mesa, along a well eroded trail on the flank of the mountain itself.

Years ago, I had walked this trail on Mother’s Day leaving very early in the morning and returning in time for Mother’s Day celebration. I remember going and returning in about 5 and a half or six hours, but I did not walk to the peak itself since I was on a time crunch that day. I remember that I was concerned about mountain lions in the early morning while hiking through a Quercus agrifolia (Coast Live Oak) filled canyon during the early dawn light. I also remember Ceanothus cyaneus (Lakeside Lilac) in flower. That was back before the 2003 fires burned over the mountain.

This time, I was traveling with Rustin (a person from my office) and several people from the San Diego River Park Foundation, including Chase Stafford. I was concerned that for May it might be quite warm, so we needed to be on the trail by 6 am. Sure enough, when the day approached, the temperature projections started increasing rapidly. In fact, the day before in Alpine, the temperature was 101°F and Escondido was 103°F. That did not bode well for our hiking day. Some people suggested that we postpone the field day but that was not an option. The afternoon the day before, the air seemed to shift, so instead of the Tuesday hiking day being projected as the hottest day in the series, I figured it would not be as hot. Besides, I had hiked up mountains in heat greater than 90°F multiple times. I just needed to be sure I had enough water and Gatorade.

Trail guides and discussions describe this as one of the most rugged hikes in San Diego County. While the peak is only 2,800 feet higher than the trailhead, descriptions of the hike mention a 4,000-foot elevation climb because not only does the trail up the mountain involve steep climbs up old jeep trails that have a thin layer of decomposed granite and sand grains that cause the loss of traction, but it has equally steep downhill climbs on the way up to the mountain. It has been described as uphill both ways. My plan was to go down and perform the plot data collection and population mapping but then to walk up to the top of the peak itself. I also planned to do some video taping, which required me to carry my heavy camera and tripod as well as the recording equipment. That was all on top of the gallon of water and roughly 1 and a 1/2 quarts of Gatorade and 1 and a 1/2 half peanut butter sandwiches as well as 2 large tangerines. I decided not to wear snake guards because of the heat and the fact that I was going to mostly stay on trails, in addition to the fact that snakes don’t care for high heat but need to cool in the shade if they get overheated. I did bring sticker gators, however, because I know it would involve walking through grassy and weedy areas.

The three volunteers for the river park went to map the Ceanothus cyaneus while Rustin was going to use an iPad to take notes of the plant species I identified in the plot. Chase Stafford from the river park also came along since he had the most experience hiking up the mountain and was observing the data collection.

We set off at about 6 am. At first the trail goes up a very steep concrete driveway, but shortly after, it passes a restroom and begins to be a series of steep switchbacks. However, as we found later, the switchbacks were possibly the least steep climb. Right after the switchbacks, the trail dropped steeply down onto one of the old jeep trails.

Though it was warm, the vegetation was in great shape. Ceanothus cyaneus, in full flower, was encountered early and was a major part of the vegetation from there on. The deep blue inflorescences dotted the hillsides. Adenostoma fasciculata (Chamise), was also in beautiful flower creating a white lacy appearance on the hillsides. The rains in May apparently prolonged the flowering period for everything and the shrubs in general appeared very healthy. With the sun’s low angle, golden light shone across the slopes, creating a tinge of color on top of the flowering chaparral and boulder-covered landscape.

Though this was all regrowth following the 2003 fire, there appeared to be little dead growth on any of the shrubs. The only place where dead vegetation occurred was in the oak lined canyon drainage that I mentioned before. We wove between two of the granitic dome peaks. The farthest one is called Silverdome on the USGS maps. Rounded boulders of all sizes poked up through the chaparral but the granitic slabs of the domes rose more as part of the slope structure than visual landscape features. This area is composed of hornblende, biotite, and leucogranite rock. The chaparral in flower, the white chamise and blue Ceanothus cyaneus that flowers long after the other species finish, and the overall green vigor created a truly beautiful landscape. I should mention that Ceanothus cyaneus is endemic to central San Diego County and is only found in the general vicinity of Crest and Lakeside with the area we were in being the center of the range.

The trail repeatedly climbed and dropped steeply. I attempted to point out the interesting plants we encountered on the trail. Calochortus splendens (Lilac Mariposa) with pale pink-lavender flowers was one interesting species and we came across a couple of bright yellow Calochortus weedii ( Weed’s Mariposa Lily), as well.

Coastal Sage Scrub habitat was limited except in one of the low areas at the bottom of a downhill stretch, probably the second one. It seemed to be slow going which is what I expected with the terrain and the steepness of the trail. I was keeping general track of where we were with the Fulcrum cell phone application. It has a Google Earth type aerial photograph background and a GPS point showing where I was. As the first hour and a half passed, I mentioned to people to watch out for Vaccinium ovatum (California Huckleberry) on the side of the trail. I had a vague memory of seeing one or a few on the south side of the trail. I had checked the museum website for the location where people had found it, so I knew along which stretch of the trail to look, plus I remembered generally what I thought was its habitat from my Mother’s Day hike many years ago.

Walking down a steep stretch that turned to a more gradual downhill, I saw one growing next to the trail. It was an individual plant with less than vigorous growth that had some dry appearance. It was near mile marker 4. The trail went on farther into an area that seemed to have greater moisture. A small rivulet crossed the trail. I looked around and saw a moist habitat that was unfortunately invaded by Cortaderia selloana (Pampas Grass). On the southside bank of the small creek grew a nice series of good-sized Huckleberry shrubs. I stopped and was looking around when I noticed a shrub that had some partially past 3-inch long flowers that looked like semi wilted trumpets. I looked again and realized that they were azaleas, wild azaleas! I know I blurted it out and then saw some more in good flower with intact fresh petals. Looking around some more, I found other medium sized shrubs with the white azalea flowers. I suppose I remembered somewhere in my mind that they grew here, but I was certainly surprised to see them. Idon’t know if the people in our little group even understoodwhat I was talking about.

This little spot was very interesting. First, the presence of California Huckleberry in Southern California is an anomaly. The genus contains 450 species from Asia to Europe & Malaysia of the northern hemisphere. Plants have been found naturally occurring from western Canada to as far south as Santa Barbara County, where I saw them on Vandenberg Air Force Base where I worked mapping resources in the 1970s. There they grew in moist canyons and places where the coastal fog settled every day, especially around the upper reaches of Honda Creek and Tranquillon Mountain.

Then they skip down to San Diego County where they occur in four general areas. One is on Bottle Peak northeast of Escondido. There, what seems like a single individual grows in a rock pile where it can resprout after fires over and over. It may be thousands of years old if there was a way to age its root base. It has also apparently been collected on Rodriguez Mountain east of Valley Center, a couple of spots north of Iron Mountain located east of Poway in an area that is more moist than its surroundings, and then on the north slope of El Cajon Mountain in a few spots. It does not occur in San Luis Obispo, Orange, Los Angeles, Ventura, Riverside or San Bernardino Counties. Something in the climate and soils in San Diego County allows for this moist-loving Redwood flora plant to persist here when its regular distribution is central and northern California.

The Western Azalea is another anomaly in Southern California. The genus Rhododendron contains approximately 1,000 species that are spread throughout the world. They range from tiny mats 2-inches high to giant trees. Their distribution is somewhat similar to the genus of Vaccinium, but a bit more expansive. Ninety percent of them are in southeast Asia, especially the Himalayas, Tibet, China and south to the Philippines, but also in Europe, Greenland and Queensland (Cox and Cox 1997). Members of this genus existed in North America 50 million years ago and represent an old lineage of flowering plants (Roane and Henry 1981). Twenty-seven species occur in North America with the greatest concentration in the Southeast. Rhododendron occidentale occurs from Oregon to San Diego County. In San Diego County, it occurs in a number of locations in the mountains and it formerly grew in a shaded forest in the Cuyamacas at Azalea Spring where a grassy slope now exists over most of its habitat following the 2003 Cedar fire, and onthis site on El Cajon Mountain’s north side. From our mountains northward, it occurs in a few spots in the San Jacinto Mountains, notably Dark Canyon below Idyllwild. However, from there, it skips up to Kern and Monterey Counties and farther north. It doesn’t exist in Orange, Los Angeles, Ventura, Santa Barbara,San Bernardino or San Luis Obispo counties. A study by Hrusa (2012) indicates that the plants in San Diego County are derived from the plants in the Sierra Nevada instead of the Coast Range, and the ones we have here in the south part of the range have larger flowers with a less distinct color patch on the corolla. This group of plants on El Cajon Mountain is the southernmost population of their entire range. The really odd thing is that these plants are not located in a moist montane forest or redwood forest area, but in chaparral. I was disturbed about the presence of the Pampas Grass in the midst of the population. I have spoken to Chase Stafford about the importance of removing the Pampas Grass.

Both of these species, the California Huckleberry and the Western Azalea, had to have continuous distribution during periods of wetter climates. One would think that there would be suitable habitat in the counties between Riverside and Kern, especially in the San Bernardino Mountains for the Western azalea, but apparently not. The California Huckleberry is another mystery since one would think there would be habitat in at least the Santa Monica Mountains.

I noticed a small yellow flowered plant growing in a moist stream rivulet edge. It turned out to be Hypericum anagalloides (Creeping St. John’s Wort), another of these disjunct plants from far away, though it too has been found in a few spots in San Diego County. It grows in a number of locations in San Diego County, a few in Riverside and San Bernardino Mountains, but then up to western Santa Barbara County to northern Kern County. In San Diego County, it has been found on the slopes near Iron Mountain, Otay Mountain, the Agua Tibia and Palomar Mountains, and the Santa Margarita Mountains. This is another species that indicates San Diego County has some factor that supports plant species that no longer exist in counties to the north.

On the other side of the trail were large scrub oaks. They had good sized, smooth edged leaves with dark green backs. They were a different looking scrub oak. On the slopes above the spring grew small trees that appeared to be these oaks. In my mind, I thought that they looked like Quercus cedrosensis (Cedros Island Oak). I thought for sure that these were scrub oaks and not trees. I could not find any acorns to assist in the identification; however, after showing photos to Jon Rebman at the Natural History Museum, he identified them as Quercus chrysolepis (Gold Cup Oak) which normally occurs above 3,500 feet in the mountains with much higher rainfall than that in chaparral areas like El Cajon Mountain. I saw that it had been collected there many years ago.

After a few moments here, we went on past an old military jeep landmark that sits with no wheels, back or engine. The trail climbed and climbed more. We passed Trichostemma parishii (Mountain Blue Curls) and plenty of Quercus acutidens (Scrub Oak) and Arctostaphylos glauca (Bigberry Manzanita).

Eventually we reached the saddle junction where one trail passes to the west up another peak, one passes to the east and up the true El Cajon Mountain, and one continues down toward the mesa located on the nose of the mountain.

The three volunteers were to proceed to photo plots for the Ceanothus cyaneus, while Rustin, Chase and I walked down to the mesa top to the Brodiaea orcuttii population. The photo plots were not expected to take long so they were going to come down and meet us afterword. By now, the temperature was quite warm. The old trail/road down the mountain flank was very eroded. Deep gullies cut through it and our job was to keep from slipping down into them. In a few spots, someone had placed rocks to make passing through the ravines more convenient. The shrubs in their vigorous growth had closed in on much of the upper portion of the trail so it was not as obvious. We by this time had encountered 5 species of Ceanothus, beginning with Ceanothus tomentosus (Woolly Leaf Ceanothus), C. leucodermis (White Back Ceanothus), C. cyaneus, C. oliganthus (Hairy Ceanothus), and C. perplexans (Cupped Leaf Ceanothus). The peak was above to our east.

We made it down to the mesa area and saw that the Brodiaea orcuttii was in full flower and very numerous. However, it was growing in the midst of patches of Castillea exserta (Purple Owl’s Clover), Clarkia purpurea (Purple Clarkia), Ozmadenia tenella (False Rosinweed), and large numbers of Navarretia hamata (Hooked Navarretia). These Navarretia hamata have not only the skunk odor associated with the species but brilliant red-maroon flowers that were just beginning to open. Eventually, they will be prominent colors on the low areas. The mesa contained grassy meadows intermixed with sheet rock slabs where the depth of the soil seemed to limit the ability for the shrubs to grow. They were meadows with a rich diversity of flowers and a few non-native species.

By this time, the temperature was hot. I had been concerned that the iPad might shut off if its black cover was exposed to too much hot sun. I had experienced that problem in the past. Sure enough, it had to be set down in the shade of a small boulder to allow it to cool in order to restart.

It also took a while to find the actual plot location using GPS on the iPad. Rustin, Chase and I were led to a number of false locations before finding the actual center, a few hundred meters away from the main central meadow. We set up the plot and estimated the count for the quadrants. Ironically, it was an area that had a lower density of the Brodiaea orcuttii because we found only 89 individuals. The rest of the plot assessment involved documenting every other plant species present and providing an estimate of cover for it. There were dozens of different species.

Attempting to estimate the total boundary of the plants seemed to be a futile effort at that time. I attempted to mark some boundaries while the iPad was cooling down. I planned to use those points to delineate the boundary using high quality aerial photographs rather than walking all over the mesa, back and forth through the open grassy areas and their edges with the chaparral.

We ate lunch and I drank Gatorade, and, also, quite a bit of water. The heat was wearing because there was no shade. I had initially indicated that I intended to climb the peak. We trudged our way back to the saddle where the trail junction was located. For various reasons, I had not practiced walking up and down the 27 flights of stairs in the office building where I work in preparation for the hike. I normally do that before events like this, but I was going to climb up to the top of the peak no matter what. I was a bit concerned about the diminishing amount of water that I had left. Zack, one of the volunteers for the river park, decided to come with me.

The climb to the peak was over a trail consisting of an eroded path through medium-sized boulders. There were many instances of high steps over boulders. I was moving slower by this time in the heat and having walked a long way already. The trail was between 1/2 to 3/4 a mile to the top, and the climb was of 800+ feet in elevation. Finally, we reached the top. I ate my last half of a peanut butter sandwich and drank the second of my two Gatorade bottles.

The top of the mountain is amid a boulder garden. There are views down the valley toward Lakeside, views to the north toward Ramona, and views of the higher Cuyamaca Mountains to the east. It felt good physically to be sitting on one of the large rock slabs on the peak. While we were there, a layer of high-altitude cirrus clouds passed over, creating a feeling of intimacy with the mountain top. Unfortunately, the clouds did little to reduce the temperature.

We did not stay long. It was about 3 pm when we started down from the top, and at the peak heat of the day. I was beginning to feel a bit dehydrated, but also I needed nutrients, carbohydrates and salt. The funny thing is that sugar and salt are normally my enemies, but I needed more then.

After coming down the peak, we made it back to the spring where I was again fascinated by the Western Azaleas and California Huckleberries. This is the southernmost location for both of these species. These are remnants from the Pleistocene.

After leaving the spring, I remembered that a climb followed. That was basically the only one that I remembered apparently. It was one of moderate length, but I had to take time because I was running out of power and it was hot. I rationed my water; I figured I had two bottles, or approximately a liter, left. I was hungry, too.

We stopped halfway up the climb and rested for a few minutes. We climbed up that hill and then it leveled off a bit and resumed going downhill again. After a while, it climbed again. We had stopped at the bottom this time. The temperature was at least 95°F. Again, we climbed the hill part and passed over the crest with the following major portion heading down hill for a while. I thought about the fact that gentle downhill may be my favorite terrain to walk on, but it was steep downhill much of the time. By now, my shirt and upper part of my pants were stiff with deposits of salt from perspiration.

In my mind, I thought sure that we must have passed the last hill. However, after a while, we came to the bottom of another hill. I wanted to sit in the shade. I found a rock on the edge of a shaded cut slope. Deer flies were buzzing my face and neck. I know I was bitten on my neck and on the side of my head. However, I was so relaxed or, maybe more accurately, burned out, and I actually dozed off for a few minutes. It was relaxing but we had to go on.

We stood up and began walking up the steep slope again and I stopped halfway, but then kept going. I was temporarily startled when I thought I saw what looked like a wolf coming toward me. Then I saw a woman who was walking that animal and a dog, and though it might not have been pure wolf, she indicated that it was in fact a wolf. Again, we passed over the crest and again went downhill, and walked on a gentle downhill. Yet again, we came to the base of a steep hill. I could not believe that there was yet another one! While walking up that morning, the excitement of the hike and the company of the people obscured my thinking about how many downhills we traversed on the way up that now translated to uphills on the way down. At this point, I was basically out of water. Once over the last pass, the walk was down some steep areas and then into the more gently descending set of switchbacks that extended for a half a mile or more. On the top of the switchbacks we had a view of the valley to the northeast near Barona. The vegetation was so green and lush looking in the late afternoon light. By now it was approaching 6 pm. The cirrus clouds reappeared. The sun had been partially obscured by cirrus clouds off and on since we were on top of the mountain. In fact, at this point, there was an overcast, filtered light as a result of the clouds and a bit of haze settled in the valley. The grassy portions were still green, later than normal for this time in the season.

Finally, we stepped onto the very steep concrete driveway portion of the trail. The volunteer took a photo of me standing by the sign for the preserve. I examined the photo and saw how gray may pants looked from the white perspiration salt. I drank about 3/4 or a full liter, and two full small bottles of Gatorade.

I was relieved to be back and getting on my way home. The hike was at least 16 miles long and, as I mentioned, at least a 4,000- foot climb, not counting the climb down on the mesa of the mountain. Considering the temperature being so high for a hike, it was a spectacular walk and at the peak of vegetation. While this hike did not take place under the most comfortable conditions, I realize what a special accomplishment it was and would not trade that experience for anything. The slopes of flowering Ceanothus cyaneus, the Western Azaleas and the California Huckleberries made it all worthwhile, not to mention being on the top of the peak among the boulders.

I would like to thank the San Diego Mitigation Management and Monitoring Program, Chase Stafford of the San Diego River Park Foundation, Rustin from AECOM, and Zack, the River Park volunteer who went up and down the peak with me.

All photos by the author