IN THE FIELD: Hiking the Pacific Crest Trail in the Caliente Wilderness Study Area

By Tom Oberbauer

The Caliente Wilderness Study Area appears as an L shape on its back, appearing like a leftover piece of land among a Tribal Reservation, a State Park, Bureau of Land Management land and other forest service lands.  It is located north of Warner Springs, west of the Los Coyotes Reservation, south of Anza-Borrego Desert State Park and east of the forest service lands near Indian Flats.  It appears to be uninspiring when examining it on a map; however, it contains a mountainous series of ridges and valleys that range between 4,000 feet and 5,000 feet. It supports one other very important feature: a significant and isolated stretch of the Pacific Crest Trail. 

Investigation on Google Earth shows a chaparral vegetation but with some indicators that appear to be pine trees.  When driving by Warner Springs or heading over to Indian Flats Campground, pine trees are visible on the skyline. 

Since I am curious about places like this, I conducted a little more research. Jerry Schad, in Afoot and Afield in San Diego County, describes it with statements about pines and even deciduous California black oaks. That piqued my interest. However, I also like to go through the Google Earth Aerial Photos over time since they have images that date back to the early to mid-1990s.When viewing the aerials back in the early 2000’s, namely 2004, it appears that a significant number of trees in the Caliente Wilderness Study Area are orange, indicating that they had died. 

The period from 2000 to 2005 was very dry for the coastal and interior portions of San Diego County, with 2002 being the driest year in more than a century of recorded rainfall history.  Only 30% of normal rain fell that season.  Examination of the Google Earth aerials from around that time indicated that as many as 50% or more of the trees in the Caliente Wilderness Study Area appeared to be dead. 

In this part of San Diego County at the elevation of around 4,500 to over 5,000 feet, there is a battle between chaparral and coniferous forest.  Pinus coulteri (Coulter pine) trees need upwards of 18 inches of precipitation to survive. Warner Springs has an average of about 17 inches per season, so it doesn’t take much more to support Pinus coulteri.  However, during periods of extended drought, the chaparral seems to be winning and many trees died.

However, the precipitation data for regions of San Diego and the Southwest is disjointed.  For example, it is difficult to find records on precipitation for Mount Laguna though there are several stations there.  One station that has data available for a couple of decades, though with some gaps, is for the Northern Fire Station.  Its data set calculated out to a seasonal mean of only 16 inches for the past 18 years.  That seemed very low to me.  It may partially be due to some gaps in data from the earlier seasons and the fact that it is located a little closer to the area where vegetation transitions from forest to chaparral than the heart of Mount Laguna.  I would have expected the mean would be over 20 inches and closer to 25.  Cuyamaca, on the other hand, has a set of data that extends over 100 seasons.  For comparison, its mean is approximately 34 inches. For Cuyamaca Lake, I calculated the mean over the last 18 seasons, the same time period as the data from the Mount Laguna Station and it came out to be only 26 inches.  This means that the climate has been running a deficit of roughly 25% of normal for the last 18 years, actually longer than that.  It is no wonder the oaks are dying in many places in our County and pines are stressed.  One should be surprised that mortality is not greater. 

With all of that in mind, in August 2021 I decided to try hiking a segment of the Pacific Crest Trail through the Caliente Wilderness Study Area, starting where the trails intercept with the Puerta La Cruz Road that goes to the Indian Flats Campground from near Warner Springs.  On some maps it is labeled as Indian Flats Road and on others Lost Valley Road. 

The day I chose (August 21, 2021) had good weather for hiking in late August. Driving from San Diego, I needed my windshield wipers off and on all the way to Warner Springs due to the heavy mist from the deep marine layer. While clearly weather with mist can occur any time of the year in San Diego County west of the mountain crest, it is not so typical of a late August day. As I drove through Warner Springs and then turned on to the road toward Indian Flats, the fog was sitting on the ground creating a lack of visibility on the paved road that held many bumps and uneven surfaces and was mostly only wide enough for a single lane. 

As I drove, it became apparent that the Adenostoma sparsifolium (Red shank) was in full flower, maybe a few days or a week past its peak.  The entire shrubs were covered with lacy, cream-colored flowers.  However, with the level of fog, at first I could not really see the full magnitude of it.

I drove on until I found the spot where a feeder trail would link into the Pacific Crest Trail.  A wooden sign indicated the trail head.  I pulled off the road and backed up into a good location to park, and placed the pass I have for National Forest lands in the hanger for the rearview mirror so that it was visible from the outside.  It was about 9 am when I began walking. 

Since the weather was relatively cool, I walked briskly along.  However, the sun, light, vegetation and fog kept distracting me to take photos and shoot video.

At this location, the vegetation was a mix of Adenostoma sparsifolium and Adenostoma fasciculatum (Chamise) chaparral.  Even without flowers, the Red shank was large and very pronounced with its yellow-green and brown color when compared to the Chamise chaparral that was dusty dark brown-green in color.  The contrast between the two species is so great that it is difficult to see that they are in the same genus.

The trail cut through what appeared to be schist, a rock with striated and banded layers of compressed sandstones that have been metamorphosed into hard rock.  Schist is a grainy, layered rock with little flecks of mica that makes it have a more interesting color and texture.  In many places, it appeared that veins of pure quartz were present with white quartz gravel and decomposed sandy material. The soil is generally a sandy mix of material without much clay, or nutrients, for that matter.  Here, it is beneath shrubs and trees that organic material has built up, so it had dark color and a loamy texture. 

On the dry areas, Opuntia phaeacantha (Desert prickly pear) with rounded pads were growing with the large grass Stipa coronata (Giant or Foothill stipa); Ericameria linearifolia (Interior goldenbush) with green, needle like leaves; and the very widespread Acmispon glaber (Deerweed).  Other major shrubs included Ceanothus perplexans (Cup-leaf lilac) with small, semi cup shaped leaves with serrated edges, and the flat leaved Ceanothus tomentosus (Ramona lilac).

The trail was climbing quite considerably as I walked along. The fog kept pulling in and going out, moving across the trail. To the west was a wall of low clouds between me and the major parts of the valleys that form Valle de San Jose and the valley with Indian Flats Campground. Whisps of fog moved on the hillsides above me as well.  It created fresh, moist and cool air that made me want to breathe deeply.

The trail kept climbing and, eventually, the fog lifted completely but a wall of clouds still stood toward the west.  I could see the ridges above with scattered Pinus coulteri.  The trail was leading generally in a northwestern direction as it worked its way up in elevation.  Before too long, it was over 5,000 feet and it began to generally lead to the east.  The Red shank in this area was exceptionally tall, maybe 15 feet or more, and the shredded bark was hanging loosely and moving in the breeze, the obvious reason that it is sometimes called Ribbonwood.  It seemed like walking through a fairy land. 

As the trail began to turn eastward, I could see more pine trees nearby, and on the slope that was now north-facing through which the trail passed, I saw younger, scattered individuals and they were close to the trail.  There, the effects of prolonged drought of the early 2000’s began to be clear.  Trunks of grown Pinus coulteri up to about a foot in diameter were scattered about, laying on the slopes all around.  The few young trees that were growing were the new generation attempting to come back from what was apparently a real coniferous forest, at least in some locations.  However, more diverse forest and woodland was also visible on the ridge above, in a gap across the saddle below, and near a gap northeast of the trail.  While the logs were an indicator of the loss, the trees that remain appeared to be in great shape as was the chaparral.  Some monsoonal rain had fallen, but as mentioned, the vegetation was probably influenced by the above normal and normal rainfall of the three of the last four years, possibly the wettest stretch in the 20-year drought.  Cercocarpus betuloides (Mountain mahogany) was also growing in a number of locations, quite commonly, and while it did not have flowers to see, it had feathery fruits that glowed white in the morning backlight. Of course, Hesperoyucca whipplei (Chaparral yucca), was quite common as was Rhus ovata (Sugarbush).  On the north slopes, Rhamnus ilicifolia (Holly-leaf redberry) grew with its shiny green leaves providing a lushness component to the vegetation.  It is notable that Toxicodendron (Poison oak) was absent.

Even though it was not a dry location, drier adapted species including Salvia apiana (White sage) with its gray, strongly scented leaves, Hazardia squarrosa (Sawtooth goldenbush) with its serrate edged leaves, and the yellow flowered Gutierrezia sarothrae (Broom matchweed or Snakeweed) with its suitable name since the inflorescences appear like yellow tipped matchsticks, were also quite common along the side of the trail and in open areas.  Eriodictyon crassifolium (Thick-leave Yerba Santa) with its tall branches and felty, oval, wrinkly leaves, was also growing in the open areas.  Eriogonum fasciculatum var. polifolium (Mountain California buckwheat) was also growing in open or disturbed areas.

Ceanothus leucodermis (Chaparral whitethorn) was overgrowing and closing in parts of the trail and, with its spiny stems and grabby branches, it is not something someone needs while walking the Pacific Crest Trail.  Quercus berberidifolia (Scrub oak) was also growing in with its own scratchy edged leaves and branches.  The shrub vegetation was complete and dense with the Red shank patches and covered slopes being the most striking.  The cover and structure of that plant is so characteristic its distribution is clearly visible from a distance.  The surroundings were exceptional and the temperature was extraordinary for a late August day.  It is difficult to explain how fortuitous and special the conditions of the light, the flowering Red shank, the terrain, the young pines on the hillsides and the weather made that morning.

The trail actually cut through several logs that fell from the dead trees.  They were mostly between 80 and 120 years old.  The younger trees growing now are a new beginning but on some steep north slopes, the logs look like toothpicks among the chaparral.

Dried skeletons of plants were visible even if not in flower.  Tauschia arguta (Southern tauschia) with the flattened pinwheel-like inflorescence and Erysimum capitatum (Wallflower) skeletons were present.  Corethrogyne filaginifolia (California sand aster; above) was one plant actually in bloom with its pinkish-lavender flowers.  In addition to the Eriogonum fasciculatum var. polifolium, a whitish form, the low growing Eriogonum wrightii (Foothill buckwheat) with its flowers along a stem rather than in a clump, was also growing in places.  Additional plants were Diplacus longiflorus (Bush monkey flower), long past flowering, but with the sticky leaves still present. 

It appeared that there were three different manzanitas growing along the trail, Arctostaphylos pringlei (Pink bract manzanita), which seemed to be the most prevalent one, but also Arctostaphylos pungens (Point leaf manzanita) and the largest growing one, Arctostaphylos glauca (Big-berry manzanita).  All three of these lack the basal burls and only reproduce by seeds. 

Being so late in the season, annual plants that were still green were scarce, but Cordylanthus rigidus (Stiff-branch bird’s beak) with fresh green leaves grew in a few locations.

On the north slope, oak trees dominated by Quercus agrifolia (Coast live oak) were growing, but in one stretch, Quercus chrysolepis (Canyon live oak) was the dominant one with some good-sized Pinus coulteri along the way.  The trail alternated between woodland and chaparral, mostly Red shank on the western part, but as it headed eastward, Ceanothus and Quercus berberidifolia (Scrub oak) were major species. I also came across some interesting semi-herbaceous plants; the green basal leaves and inflorescence skeleton of Penstemon spectabilis (Showy penstemon), a very show purple and pink wildflower when in flower, and the purple leaves of the perennial, shade dwelling Keckiella ternata (Summer bush penstemon) that has red-orange flowers when they are present.  Clematis lasiantha (Pipestem virgin’s bower) was growing in with and climbing over the shrubs. 

Additional plants nearby included Quercus wislezenii (Scrub live oak) shrubs, skeletons of Frasera parryi (Deer’s ears), an odd herbaceous plant that grows with a central stalk and four petaled flowers, dried up Castilleja foliosa (Woolly Indian paintbrush), the fern Pellea mucronata (Bird’s foot fern), and Galium andrewsii (Phlox-leaf bedstraw), the small, green plant with needle like leaves that grows in clumps beneath the shrubs. 

The trail passed individuals of younger Pinus coulteri and dark chaparral and oak woodland before it switched over to a south facing slope. It was crossing a saddle and headed out into the open with lower growing shrubs. However, it was the top of a deep canyon that fed into a deeper canyon coming off the west side of Hot Springs Mountain. The view was spectacular because the trail was passing around a ridge and moving directly over the canyon’s thousand-foot-deep chasm. The drop between the trail and Hot Springs Mountain was almost shocking when it first came into view. It was a totally unexpected dramatic landscape. The north slope of the hill to the south had lines of moderately sized pines growing on top with sun bleached logs on the slope from trees that died in the early 2000’s.The pine trees on the ridge above also marked the ridge line with their silhouetted forms clearly visible. The canyon below was filled with oaks and some pines, traipsing upward onto the slope of Hot Springs Mountain that stood to the east like a dark vertical, heavily forested mass above the deep canyon. It appeared as an impossible landscape, impenetrable for anyone due to the density of the vigorous vegetation.

The geology seemed to change while proceeding on the northwest side of the deep canyon.  Rock piles existed on hill tops and the slopes had decomposed gravels, but more, the slopes were covered with small boulders of granitic material.  Pines were still growing on the ridge above as the trail turned north around a point, and another valley, much more shallow, came into view in the distance.  My goal had been to get to that valley that was described by Jerry Schad as a glen with oaks and pines.  It was still a way off.  The trail turned around the point and headed slightly northwest at the base of a north facing slope.  Ericameria parishii, a tall distinctive shrub with yellow flowers at the time, sometimes called the Golden fleece, was growing in some spots along the way.  The most notable plant growing along this trail was actually a tree on the south side of the trail, Quercus kelloggii (California black oak).  It was roughly four meters tall, and consisted of multiple trunks.  It was a brighter green than any of the other shrubs and trees in the area.  It was like finding an old friend all by itself.  The fact was that a good-sized stump, about a foot and a half or more in diameter, was on the ground and the tree that was growing was a set of resprouting stems.  The old log portion of the tree lay down in the shrubs on the north side of the trail.  The tree must have been a formidable size before it died back as the result of fire.

The Coyote Fire that was caused by lightning burned into this area in July of 2003.  However, the western parts of the area on the earlier portion of the trail did not burn in the Coyote Fire and have not burned for a very long time.  The Coyote Fire burned the part of the land passed through by the trail from the saddle north eastward with the saddle as the dividing point; generally coinciding with the granitic area.  That fire burned the Quercus kelloggii, killing the upper part which was cut, probably so it would not fall on the trail. 

I kept walking where the trail turned northward and it became fully contained in rocky and bouldery granitic rocks rather than the schist material of the first part of the route.  Additional plants of interest that appeared included Ericameria cuneata var. spathulata (Wedge-leaf goldenbush), a low growing, small shrub with flattened spatula like leaves.  It grew right on the rocks in crevices and on gravelly soil.  As I proceeded farther, it became clear that Jerry Schad’s green glen with oaks and conifers was not as it had been.  Besides the fact that this time of the year it was far from green, many oaks appeared dead and conifers were rare there now.  Furthermore, its access was down a steep, rocky slope that did not look so fun after walking six miles with six more to go back.   I turned back and decided to eat lunch at the Quercus kelloggii.  Hearing the leaves rustle in the low afternoon breeze was pleasant.  The oak was about 5.75 miles from the beginning of the trail.  Solidago velutina (California goldenrod) grew beneath the tree as well as Drymocallis glandulosa (Sticky cinquefoil).  The leaves with the multipart leaflets were characteristic of the cinquefoil plant as well as the scent of the leaves, a greasy, minty odor.  Frangula [Rhamnus] californica (California coffeeberry) also grew nearby.  Rhus aromatica (Basket bush) was also growing in the area. 

Young pines were growing directly up slope from the oak. It was not clear to me that this was the only Quercus kelloggii in the area and I thought I saw another off in the distance but I could not verify that it was.  Jerry Schad seemed to indicate there were others in the area when he wrote his book in the 1980s, but the one I saw near the trail was the only one I could verify.

I started my way back, retracing my steps on the trail.  The temperature remained bearable but I still drank a large amount of water, actually nearly a gallon by the time I got back to the trail head.  The large cloud bank was still laying off to the west, but the air felt very dry, much different than earlier in the morning. 

This area of San Diego County with the variable terrain and vegetation is really fascinating.  While I would have liked to see it with the forests that existed 20 years ago, the trees that are growing there now and the chaparral are truly beautiful and apparently quite healthy.