Ahmanson Ranch Trail Runs

The Victory Trailhead at Ahmanson Ranch -- now Upper Las Virgenes Canyon Open Space Preserve

Following are brief descriptions, Google Earth images, and a Google Earth KMZ file of several trail runs at Ahmanson Ranch — now Upper Las Virgenes Canyon Open Space Preserve. These are shorter courses, generally on dirt roads, that extend as far west as Las Virgenes Canyon. Some longer runs in this area are listed in the Santa Monica Mountain Conservancy Open Space section of my Google Earth KMZ Files of Trail Runs page.

The distances and elevation gains/losses specified are for a round-trip from the Victory trailhead, and are approximate. Any of the courses can be lengthened by 2.6 miles by starting at the El Escorpion Park trailhead at the west end of Vanowen. This also adds about 350′ of elevation gain/loss.

To simplify labeling the courses, the main (dirt) road between the Victory trailhead and Las Virgenes Canyon is referred to as the “Main Drag.” This term was coined by long-time Ahmanson runner Jon Sutherland. The Upper Las Virgenes Canyon Open Space Preserve map refers to this road as the East Las Virgenes Canyon Trail. The road also has been designated a segment of the Juan Bautista De Anza National Historic Trail.

Here is the Google Earth KMZ file for the trail runs described below. To avoid clutter, when the file is opened in Google Earth, only two of the courses are initially displayed. Additional runs and variations can be viewed by clicking on the checkbox for the course.

If you are new to running at Ahmanson, a couple of things to watch out for are rattlesnakes and the heat. It also gets very muddy when it rains. Enough talking, let’s get to running…

Lasky Mesa Mary Wiesbrock Loop (3.7 mi, 270′ gain/loss)

Of the courses listed, this run has the least amount of elevation gain. Following a short stretch of downhill, the route does a big switchback and climbs up to the eastern shoulder of Lasky Mesa. The climb is fairly moderate, but comes early in the run. About 1.2 miles from the Victory parking lot is a “Y” junction, marked by some rocks and a trashcan. (A pair of ravens also like to hang out here.) This is the start of the 1.3 mile loop that honors Mary Wiesbrock, whose tireless efforts helped save Ahmanson Ranch from development.

If you do the loop counterclockwise, taking the right fork at the “Y,” in about 0.6 mile the Mary Wiesbrock loop turns left (south) onto a connector road. This leads to a “T” junction and the southern leg of the loop. A left turn at the “T” continues east through grassland to some ranch buildings, and another left leads back to the “Y” at the start of the loop. All of the loop is on dirt road, and there are some trail markers.

If you miss the turn onto the north-south connector, the north road continues to an overlook at a prominent Valley Oak on the western end of Lasky Mesa. From this point the extension of the south road can be used to return to the standard route and the “Y” junction. This extended version of the Mary Wiesbrock loop increases the length of the course to 4.25 miles.

Main Drag – Lasky Mesa Loop (3.7 mi 380′ gain/loss)

Except for a short stretch at its beginning and end this course is a complete loop. It starts the same as the Lasky Mesa Mary Wiesbrock Loop, but instead of turning left up the big switchback, it turns right onto the Main Drag.  Here, the road curves downhill and then turns west. After passing through a grassy riparian area, the road climbs a short hill and continues westward.

About a mile from the parking lot, a prominent oak tree can be seen on the crest of hill, directly south of the road. This is the “lollipop tree.” In about a tenth of a mile, at a junction with a trashcan and trail marker, this course forks left (south) off the Main Drag , and drops down to another grassy riparian area along the main drainage of East Las Virgenes Canyon. From here the road climbs about 1/2 mile up to Lasky Mesa.

At the top of the climb the road intersects the northern leg of the Mary Wiesbrock Loop. There are three route choices here. This course curves left (east), and then forks left and follows the winding road along the scenic northern edge of Lasky Mesa through valley oaks to the “Y” junction of the Mary Wiesbrock Loop. From here it’s a little over a mile back to the parking lot.

A slightly longer variation also curves left at the top of the hill, but forks right and continues south up a short grade. This leads to a “T” junction and the southern leg of the Mary Wiesbrock Loop. Continuing on the loop counterclockwise, this variation circuits Lasky Mesa’s grasslands around to the same “Y” junction as the standard course.

The third, and longest, variation turns right at the top of the long climb, and does the extended version of the Mary Wiesbrock Loop counterclockwise around the mesa to the “Y” junction.

There is also a scenic 3.3 mile variation that branches from the standard route in the grassy area just before the long climb, and ascends a well-used single track southeast to Lasky Mesa just west of the “Y” junction of the Mary Wiesbrock Loop. A left turn (east) here leads to the “Y” junction in about 200 yards.

Out & Back to Las Virgenes Canyon (5.3 mi,  465′ gain/loss)

This course starts the same as the Main Drag – Lasky Mesa Loop, but instead of turning left a little past the Lollipop tree, it continues west on the Main Drag all the way to Las Virgenes Canyon.

This is a good course for a tempo run — particularly the out leg to Las Virgenes Canyon. When the weather is hot the return leg (gradual uphill, often with the wind) can be tough.

If this run is extended to the Las Virgenes Rd. Trailhead it adds about 0.8 mile to the out and back course.

Las Virgenes Keyhole Loop (6.6 mi, 625′ gain/loss)

This is an excellent and varied course that loops through Las Virgenes Canyon and crosses Las Virgenes Creek twice. Following Winter rains you might even get your shoes wet!

The run starts the same as the Out & Back to Las Virgenes Canyon, but turns right (north) off the Main Drag at a junction (with a trashcan) at about the two mile point. From here, it is about a mile to Las Virgenes Canyon, and another mile down the canyon to the turn back onto the Main Drag.

There is a 7.3 mile variation of this course that turns south off the Main Drag about 1/3 mile east of Las Virgenes Canyon and follows a pipeline service road up to the western end of Lasky Mesa. This climb is known as “The Beast.” Some other roads/trails in this immediate area are posted “Restoration Area — Please Keep Out” so be sure you’re on the right trail.

Coyote Candy

Hollyleaf cherry (Prunus ilicifolia) on the Chumash Trail

Sometimes growing as large as a supermarket cherry, the sweetish, thin-pulped fruit of hollyleaf cherry (Prunus ilicifolia) is a favorite snack of coyotes.

These are on the Chumash Trail in Rocky Peak Park. This is the first year since the 2003 Simi Fire that there has been a sizable hollyleaf cherry crop along the trail.

It is commonly reported that an “acid treatment” in the digestive tract of a coyote or bird is required for germination. However, according to the University of Texas Native Plant Information Network Native Plant Database, fresh seeds require no treatment.

Related post: Holly-leaved Cherry

Hawk, Bobcat and Rabbit

Ka-ree… Ka-ree… Ka-ree…

I heard the angry cries at least a quarter-mile away. The screams were incessant. Running along the dirt road, I emerged from a grove of oaks and turned west — running down a short hill and then up another. Cresting the rise, I paused to search the parched terrain.

The Winter rain season had been the driest on record, and Summer heat was now oppressive, abusing the animals and desiccating the chaparral. A few clouds cluttered the sky, but they would bring no rain. The cries continued.

Ka-ree… Ka-ree… Ka-ree…

The screams seemed to be coming from a group of rocks and oak trees near the campground. I left the road and slowly walked through the brush in the direction of the shrill shrieks. As I approached, the intensity and urgency of the screams increased. Intimidated, I stopped.

KA-REE… KA-REE… KA-REE…

There was not only fury in those cries, but a warning.

To my left, something stirred. Slowly I turned and looked down. For a moment I just stared. Rabbit lay face-down against a rock, twitching. Up in the oak tree, Hawk continued his irate cries.


KA-REE… KA-REE… KA-REE…

Suddenly, there was motion to my right, and Bobcat bolted from the brush. Hawk swooped in pursuit. His broad tail flared and wings twisted one direction and then another, as he followed the abrupt zigs and zags of Bobcat through the rocks, up the hill, and out of view.


KA-REE… KA-REE… Ka-ree… ka-ree…

Afterward: This encounter occurred during a run at Sage Ranch Park in July of 2002. I continued my run, and when I returned about 30-40 minutes later, the rabbit was gone. The photographs were taken during the encounter.

Thistledown on Ragweed

 

Adjacent to Las Virgenes Creek, not far from the cattails of Linear Green, is a sizable plot of western ragweed. On a recent run I noticed several tufts of fluff caught on the ragweed and backlit by the afternoon sun.

Investigating, I found the source of the tufts about 15 yards away — a patch of bull thistle — an invasive weed that is found throughout the U.S.

Like a dandelion, bull thistle seeds are attached to a downy pappus, and can be dispersed by wind. The rate at which these plumed seeds fall through still air is quite low — less than 1.5 ft/sec. This is slower than the minimum sink rate of a high performance sailplane. For a given plant height, the lower the sink rate, the farther the seed can potentially be dispersed from the parent plant.

Even though the plumed seed of bull thistle (Cirsium vulgare) is much larger and heavier than a dandelion’s familiar tuft, it is reported to have about the same ratio of plume area to seed weight. This is a key factor affecting the sink rate. However, the bull thistle’s seed is reported to sink at about a 15% slower rate than the dandelion’s. This may be attributable to aerodynamic and structural advantages of the secondary branches found in the plume of the bull thistle, but not in the dandelion’s.

Related technical papers:

Diaspore Size, Shape, and Fall Behavior in Wind-Dispersed Plant Species

Glenn R. Matlack
American Journal of Botany, Vol. 74, No. 8 (Aug., 1987), pp. 1150-1160
Botanical Society of America

The Aerodynamics of Plumed Seeds

D. F. Greene and E. A. Johnson
Functional Ecology, Vol. 4, No. 1 (1990), pp. 117-125
British Ecological Society