By Tom Oberbauer
Back in January of 1978, I hiked up onto Corte Madera Mountain with a friend, Tom Scott (now with UC Berkeley and UC Riverside), who had been studying Golden Eagles in San Diego County. Bald Eagles were wintering at Corte Madera Lake. After postponing the hike due to rain, that was a good rain season, we drove out to Corte Madera Lake, which was accessible because Tom Scott had a key, and we hiked up the north side of Corte Madera Mountain on a little used trail. The trail climbed through a woodland of mostly coast live oak (Quercus agrifolia), but also Coulter pine (Pinus coulteri), as well as Jeffrey pine (Pinus jeffreyi). It was foggy going up and the view was obscured.
Years pass and situations change. Corte Madera Mountain is vulnerable to fire and most of the mountain burned in the 1970 fire. Coulter pine acts like it has serotinous cones. The large, heavy cones become scorched and blackened but the scales separate to allow the bright red seeds and wings to be released. The seeds land on bare mineral soil due to the fire, with no easily desiccated duff help the next generation sprout and begin to grow.
Coulter pine trees live quite a long time, likely hundreds of years, but many don’t get that chance. Before the 1970 fire, the density of trees visible from Interstate 8 was higher than it is now, but trees did generate and grow after 1970 and continue to grow now.
As one drives east of Alpine and east of the junction with SR 79, one can look to the south and see the pines growing on the ridge top of this sky island mountain.
For a long time I had considered hiking Corte Madera Mountain from the standard trail that leaves from the southeast on the Lake Morena side. However, different little factors seemed to postpone the hike and other issues prevented any such adventures for quite a while. I had hoped to hike it in 2020, a good rainfall season, but that did not happen. One of my biggest fears for the mountain almost came to become fact when the Valley Fire started west of Japatul Road. It burned through an area in which I was conducting vegetation surveys a week after I was there, around replaced power poles where vegetation restoration had taken place, burning through areas that were scheduled for surveys the following week. It stubbornly burned for a number of days and crept its way toward Corte Madera Mountain. A fire on the mountain now would not only destroy the pine forest still recovering from the 1970 fire, it would set back a hike through any type of real forest by decades. I was heartened so see that the fire was stopped after burning through the Pine Creek Wilderness on some mesa lands, but it did not reach Los Pinos Mountain with its sky island forest of Coulter pines and it did not hit the south slope of Corte Madera Mountain.
Even though 2021, the year of my recent hike, was dry and most locations received 50% or less of normal precipitation, vegetation in much of the County did not seem overly stressed, probably partially due to the fact that the rainfall seasons of the previous two years were relatively normal. In addition, snow fell multiple times above 3,500 feet and the precipitation came at opportune intervals to allow for vegetation to grow and not appear too drought stressed in mid spring at the time of this hike. I was determined to climb it in 2021 before there were any more fire scares.
In early May 2021, I drove with my son Paul out onto Buckman Springs Road. It was a warm day but we started early and were at the trail by 7 am or shortly after. The access road is a long, wash boarded stretch with a decomposed granite surface that also carries vehicles heading toward the Corral Canyon OHV Area. At a hairpin turn several miles in, a small parking pull-out exists for those who want to hike the area.
The morning was still cool but we knew it was going to warm up quickly. The trail began in a shaded canopy of oaks, and involved walking along a dirt road that appears little used. The oaks seem to have suffered through the 20-year drought that the entire county has been suffering. Numbers of trees were dead standing or dead fallen. However, the vegetation was still quite interesting.
The canyon bottom was filled with coast live oaks and western sycamores (Platanus racemosa), with large specimens growing in an actual gallery forest, though some had died. Mixed into the woodland were some interesting annuals and herbaceous perennials like purple and white flowered Chinese houses (Collinsia heterophylla), and stiff branched birds beak (Cordylanthus rigidus) with flowers that look like a baby birds’ mouths, dark blue Parry’s larkspur (Delphinium parryi), the brownish flowered California peony (Paeonia californica) with finger like leaves, the prostrate lobe leaved Pacific sanicle (Sanicula crassicaulis), and the twining wild cucumber (Marah macrocarpa) that has green somewhat maple shaped leaves and that climbs over other vegetation and small shrubs. Other shrubs included the orange tube flowered summer bush penstemon (Keckiella ternata), the silver leaved canyon silk tassel bush (Garrya veatchii), the typical deerweed (Acmespon glaber), and the yellow flowered, ever present yellow yarrow (Eriophyllum confertiflorum). Additional larger shrubs included point leaf manzanita (Arctostaphylos pungens), sugar bush (Rhus ovata), holly leaf cherry (Prunus ilicifolia), mountain mahogany (Cercocarpus betuloides), and California buckwheat (Eriogonum fasciculatum). Eventually the trail left the road and continued almost straight west, emerging from the oak forest into dense chamise (Adenostoma fasciculatum) dominated chaparral. Also mixed in was cup-leaf lilac (Ceanothus perplexans) but also clusters of scrub oak (Quercus x acutidens) and blue flowered Ramona lilac (Ceanothus tomentosus). Other plants include mountain bluecurls (Trichostema parishii), wild hyacinth (Dipterostemon pulchella), sawtooth goldenbush (Hazardia squarrosa), and in some open areas grand lotus (Acmispon grandiflorus; below).
The soil was red and adjacent to Los Pinos Mountain that exhibited all of the characteristics of gabbro soil as it was approached to the left or the south. It is a cone shaped peak, has few boulders, and has an extensive cover of dark chaparral but also clusters of Coulter pines in groves on the peak and especially the north slope. The trail we were traveling intersected another road in a saddle where the road formed a central intersection with one road proceeding north into the Corte Madera Ranch, one going south up to the top of Los Pinos Mountain by heading around its west side, one proceeding straight west to eventually loop around to the west side of Corte Madera Ranch, and one that went up what was apparently a fire break that passed directly up to the peak of Los Pinos Mountain.
As one approached the intersection, the south face of Corte Madera Mountain came into view. While it is not a sheer vertical cliff face like Half Dome in Yosemite, it has a strong, abrupt cliff face that is nearly 600 feet (190 meters) tall. A sign near the intersection indicated the importance of cliff faces for raptors, including Golden Eagles and Peregrine Falcons. In fact, while it is a popular location for rock climbers, it is shut down seasonally so that the raptors are not adversely affected while nesting.
Just west of the intersection the first Coulter pines were encountered. The elevation is high enough that rainfall can support the trees. Where I grew up east of El Cajon, my grandmother had a Coulter pine that was never watered and utilized only rainfall for growth. It was a bit stunted looking but it was densely packed and was famous to us as a place where Great Horned Owls roosted during the day. We received about 17 inches of rainfall on average yet this tree and nearby clusters and lines of Arizona cypress (Hesperocyparis arizonica) could survive without supplemental water, though some of the cypress on the more exposed slopes did not do as well over time.
I would estimate the average precipitation in this place would be like Pine Valley or a bit more, roughly 20 inches, but who knows what average is anymore since the 20-year drought has continued with many places receiving 25% less than the long term mean for more than 20 years. These pines appeared to be in good condition. A number of their cones were on the ground, massive, heavy and spikey, even more massive than others I have seen on Black Mountain and parts of the Cuyamaca Mountains. The trail to the peak turned and followed the Corte Madera Road for a few hundred meters and several sharp curves before it headed off to the west up the mountain. Interestingly, even though it has been a dry rainfall season, ponded water still stood on the road bed with the red soil creating orange mud. Near where the trail turned off toward the peak, more annuals were present including ball gilia (Gilia capitata) with its pale lavender ball shaped inflorescences, purple clarkia (Clarkia purpurea; below) with its dark maroon colored, four petaled flowers,
California thistle (Cirsium occidentale var. californicum), coast baby star (Leptosiphon parviflorus; right),
with small, bright yellow star shaped flowers that grew in small but dense clusters, some areas of white pincushion (Chaenactis artemisiifolia), and patches of the feathery green leaved white-flowered yarrow (Achillea millefolium: below) plants not yet in flower.
Whenever I see Achillea millefolium, I am reminded that it has what may be the most widespread distribution of any plant in the world and was used by the native people for a wide variety of treatments for ailments. I saw it in Tierra del Fuego at the tip of South America, but it may have been introduced there. There was also a showy patch of golden ray pentachaeta (Pentachaeta aurea: below) with its bright yellow orange flowers the size of a quarter, each with numerous ray flowers.
That plant in particular is always a treat to see with the interesting flower heads that vary in size and number of flowers. This is where the real climb began. It was along a series of steep climbs that moved nearly straight overall but with small squiggles as one climbed to the northwest. It had steep and rocky sections and was mostly out in the open chaparral, again. It continued to climb until it reached a relatively high level and then turned northward at a large split boulder with a somewhat picturesque appearance with a view above the Corte Madera Valley.
We reached trees here, both Quercus agrifolia and Pinus coulteri but also canyon live oak (Quercus chrysolepis) and a bit farther on Jeffrey pine (Pinus jeffreyi). The trail did some odd things where it cut along old logs and had some steep stretches where old decaying oak leaves made it a bit slippery. Its route was not perfectly clear at all times but if one paid attention, it was no problem. It continued to climb through the north facing wooded slope with glimpses through the trees of the green meadow and lake in the valley below. Then, unexpectedly, the trail dropped in elevation, going steeply down toward another saddle where it leveled off and again, passed out into the open chaparral composed here of Arctostaphylos glandulosa dominated vegetation. In fact, the 1970 vintage chaparral was so thick and tall that it obscured views of the valley to the north.
The trail gradually climbed back through open, gentle terrain and reached another high point in more, dense, Arctostaphylos dominated chaparral before it turned south and cut down a shallow valley and up again toward the peak. Up on top of the flatter areas before the last shallow valley, scattered pines grew directly out of the chaparral, and again, this chaparral is tall. At 50 years old, it is now mature and the trail cuts through it like a narrow trough. The light and the view across this rolling topland was pleasant with the occasional trees as individuals or with a few others. One gets the feeling that it is much higher in elevation than it is with the open, scattered trees in the dense chaparral, similar to the feeling of climbing on the upper slopes of Mount San Gorgonio in the San Bernardino Mountains. The forest may have been more dense before the 1970 fire. The mature chaparral was more than 2 meters tall in places with chamise and Quercus x acutidens. The trail ended at the peak that was a series of large boulders. It was the top of the cliff face drop off. The views from the peak were mostly southward and westward, over deep valleys clothed with heavy, dark chaparral and oaks in the drainage bottoms. Los Pinos was a raised cone shaped mountain with groves of pines and a lookout tower on its top, another sky island refuge for pine trees.
Creeping sage (Salvia sonomensis), a plant found in a number of locations in San Diego County skipping down from Central California, was in full flower (below). This low growing plant is partial to gabbro soils but not restricted to it.
At one point near the saddle between the hilltop with the most pines and the more open stretch to the peak, there was a large shrub with bright green, fresh growth, the color of Quercus kelloggii (California black oak) when it puts out new leaves. It was clearly not that because the leaves were only lightly lobed and notched. It was Quercus x palmeri below) that is a hybrid between Quercus kelloggii and Quercus wislizenii (Interior live oak). It is a beautiful shrub with a color that I noticed from a distance, and the leaves are, in fact, generally deciduous in the fall and winter. I have seen it a few locations near Hell Hole Canyon County Preserve and El Cajon Mountain in San Diego County, but it is not very common. In most places, it grows where the parents, Quercus kelloggii and Q. wislizenii, are not present or at least not common.
The walk back down and through the forest seemed to pass quickly and presented a different perspective. I never have a problem walking back the same way I came because I always see things differently and usually find different things. However, once we were back down on the part that left from the intersection, the distance still seemed far. The oaks in the bottom provided welcome shade after the open chaparral stretch but the fatigue from walking so long seemed to be setting in and I was realizing how many trees really have died from drought and extreme circumstances like the Goldspotted oak borer. It is still really beautiful but sad to see old and large trees die.
Other blooming species observed included prairie flax (Linum lewisii) and showy penstemon (Penstemon spectabilis).