Category Archives: upper las virgenes canyon open space preserve

Goldfields, Silt Slides, Oak Leaves, Invasive Thistle, Rough Trails, and a Reminder to be Watchful

Goldfields blooming on Lasky Mesa - March 2024
Goldfields blooming on Lasky Mesa

Following are some notes and photos from runs in Upper Las Virgenes Canyon Open Space Preserve (Ahmanson Ranch) during March 2024.  Spring is here! The hills are green, goldfields and other wildflowers are blooming, and Las Virgenes Creek is flowing.

Goldfields and Other Wildflowers

The first goldfields (Lasthenia gracilis) of 2024 began to bloom on Lasky Mesa at the end of February. Now, bright yellow patches of these “belly” flowers are scattered across the mesa, adding a brush of color to the roads and trails of Ahmanson Ranch. The cheery flowers usually disappear with the first spell of hot and dry weather. Looking ahead, more rain and cool weather are forecast Easter weekend, and extended temperature outlooks are mixed. Hopefully, the goldfields will be around for a few more weeks.

Catalina mariposa lily at Ahmanson Ranch. March 27, 2024. (thumbnail)
Catalina mariposa lily. Click to enlarge.

Some other wildflowers are also blooming. Blue Dicks usually flourish following a wet Winter, but this March are less widespread than usual. Red maids are also less numerous than normal and their flowers somewhat smaller. The elegant white flowers of Catalina mariposa lily are just starting to bloom.

Thanks to T.S. Hilary’s false Spring and copious Winter rain, the hills of Ahmanson Ranch have been green since early October.

Silt Slides
Slides of silty soil in Upper Las Virgenes Canyon Open Space Preserve (thumbnail)
New (left) and old slides of silty soil. Click to enlarge.

With all the rain, small, shallow mudslides have been common along road cuts and other steep slopes of Ahmanson Ranch. The area has fine-grained silty soil. When saturated, it can generate a slurry of silt and debris. The numerous scars on the hillsides suggest this is a primary mechanism of erosion in the area.

Valley Oaks

After losing their leaves in December, the Valley Oaks at Ahmanson are now budding and sprouting. Some trees already have new leaves, while others are still bare-limbed. The period valley oaks are without leaves varies from year to year depending on rainfall, temperature, sunshine, and other factors.

Invasive Milk Thistle
Milk thistle in Las Virgenes Canyon
Milk thistle. Click to enlarge.

Milk thistle thrives during wet years, and it’s been very wet. We’ve had two consecutive wet years, plus a tropical storm thrown in for good measure. The invasive is sprouting in areas where it doesn’t normally grow and growing prolifically in areas where it is established. In a few months, milk thistle may look like it did in May 2005, following the record 2004-2005 rain year.

Rough Trails
Upper Las Virgenes Creek (thumbnail)
Upper Las Virgenes Creek. Click to enlarge.

Profuse rainfall is a two-edged sword. It revitalizes the ecosystem, turns the hills green, recharges the creeks, preserves the trees, produces wildflowers and more. But it can also be problematic — triggering slides, washing out and damaging trails, and promoting plant growth that chokes trails and increases the fire hazard.

At the moment, the roads and trails at Ahmanson are a bit rougher than normal, particularly in East Las Virgenes Canyon. Use and drier weather will gradually smooth out the ruts and rugosities, but we’re going to be picking foxtails from our socks for some time to come.

Upper Las Virgenes Creek is still flowing — including in the canyon’s upper reaches. Sometimes, there will even be a log or two in place to help keep your shoes dry.

And A Reminder to be Watchful
Baby rattlesnake at Ahmanson Ranch (thumbnail)
Baby rattlesnake. Click to enlarge.

I sometimes stretch at the info kiosk at the Victory trailhead before running. Today, as I placed my hands against one of the kiosk posts and started to stretch, I glanced down. Disturbingly close to my feet was a small snake. Adrenaline flowing, I checked the head and tail and then checked them again. I stepped back and began to breathe. It was a gopher snake. But it could have just as easily been a rattlesnake. In fact, later on that run, I encountered a baby rattlesnake. That day and the next (March 20 and 21), I saw a total of four gopher snakes and two Southern Pacific rattlesnakes.

Some related posts:

Ahmanson Ranch  and Las Virgenes Creek After Six Days of Rain
East Las Virgenes Canyon After a Seventh Day of Rain
A Second Spring at Ahmanson Ranch
Looking For Local Impacts of Tropical Storm Hilary

East Las Virgenes Canyon After a Seventh Day of Rain

East Las Virgenes Canyon After a Seventh Day of Rain

A very wet East Las Virgenes Canyon and Trail on February 8, 2024,  following seven days of rain. This was by far the wettest start to February in Los Angeles since recordkeeping began in July 1877.

Related post: Ahmanson Ranch and Upper Las Virgenes Creek After Six Days of Rain

Ahmanson Ranch and Upper Las Virgenes Creek After Six Days of Rain

A female (left) and male mallard enjoying a large puddle adjacent to the Victory Trailhead parking lot.
A female (left) and male mallard enjoying a large puddle adjacent to the Victory Trailhead parking lot at Ahmanson Ranch.

After January 2023’s torrential rains and Hurricane/Tropical Storm Hilary’s drenching in August, here we are again, experiencing record rainfall.

Over the first six days of February 2024, Downtown Los Angeles recorded 10.2 inches of rain. That’s almost three-quarters of L.A.’s normal ANNUAL rainfall in just a few days and the wettest start to February on record! Some stations in the Santa Monica and San Gabriel Mountains recorded even more — over 13 inches in some locations!

How much did it rain at Ahmanson Ranch (Upper Las Virgenes Canyon Open Space Preserve)? Unfortunately the Remote Automated Weather Station (RAWS) on a hill between Upper Las Virgenes Canyon and Cheeseboro Canyon hasn’t been accurately measuring precipitation. A citizen weather station (KCAWOODL130) near the Victory Trailhead at Ahmanson Ranch recorded over 11 inches from February 1 – 6. Another station near Cheeseboro Road in Agoura (KCAAGOUR41) recorded over 9 inches.

Whatever the amount, it was a lot. Here is a short video, from a run at Ahmanson Ranch on February 7, 2024, to check out the conditions and creeks.

As I write this, more wet weather is forecast to affect the Los Angeles area, beginning sometime over the weekend of February 17-18. We’ll see!

Update Friday, February 16, 2024.  Latest forecast for Los Angeles area suggest the rain may hold off until Sunday night or Monday.

Spring Wildflowers in December?

Paintbrush blooming in mid-December in Cheeseboro Canyon in Southern California near Los Angeles
Paintbrush blooming in mid-December in Cheeseboro Canyon

The paintbrush above, and the following Spring-blooming wildflowers were photographed on December 14,2023, on a trail run from the Victory Trailhead of Upper Las Virgenes Canyon Open Space Preserve. With the exception of the black mustard, the wildflowers were found along a half-mile stretch of dirt road connecting upper Las Virgenes and Cheeseboro Canyons.

The false Spring was the result of rain from Tropical Storm Hilary in August, an extended period of wetter than normal weather, and somewhat warmer Fall temperatures. The Water Year that ended September 30, 2023 was the seventh wettest on record for Los Angeles and Calendar Year 2023 was the sixth wettest.

Some related posts:
– A Second Spring at Ahmanson Ranch
– Seventh Wettest Water Year in Los Angeles Results in Rarely Seen Trail Conditions
– Looking For Local Impacts of Tropical Storm Hilary

 

I Stop for Cumulus Clouds

Cumulus cloud - Photography by Gary Valle'

On my way to upper Las Virgenes Canyon from the Victory Trailhead of Ahmanson Ranch, I had to stop running and marvel at the intricacy and beauty of this cumulus cloud.

The cloud developed as another weak trough was passing through Southern California. For a few weeks the long-range outlooks have been advertising a change to a wetter weather pattern, but the expected transition keeps being delayed.

More posts from the category Nature & Clouds.

Topic Is: Things Crawling on the Ground at Ahmanson Ranch

A Southern Pacific rattlesnake on the dirt road above the Victory Trailhead of Upper Las Virgenes Canyon Open Space Preserve (Ahmanson Ranch).
A Southern Pacific rattlesnake on the dirt road above the Victory Trailhead

I’ve encountered some interesting things crawling on the ground at Ahmanson Ranch this Fall.

Gopher snakes are the snake I see most frequently at Ahmanson Ranch (Upper Las Virgenes Canyon Open Space Preserve). Recently, I came across this sizable gopher snake crossing the dirt road on the long switchback above the Victory Trailhead. Despite the small size of its head, a gopher snake can consume prey much larger than might be imagined.

The impressively colored and patterned lime green caterpillar of the white-lined sphinx moth.
Caterpillar of the white-lined sphinx moth.

Just a few days ago — in virtually the same place as the gopher snake — I encountered a good-sized Southern Pacific rattlesnake serpentining across the dirt road and continuing up the brush-covered hill (video). The snake reminded me of a rattlesnake I photographed near the Victory Trailhead in November 2019. In the Fall, Southern Pacific and other rattlesnakes are said to return to the same den year after year. This rattlesnake had about 13 rattle segments, and the November 2019 rattlesnake about 10. Both were headed in the same direction. Might they be the same snake going back to a den?

On that same run as when I encountered the rattlesnake, I came across this remarkably colored and patterned caterpillar on Lasky Mesa. It turns out to be the caterpillar of a white-lined sphinx moth — a type of hummingbird moth.

A few days later — near the same place where I encountered the gopher snake and rattlesnake — I happened upon this tarantula scurrying across the road. Male tarantulas search for mates in the Fall.

Some related posts:
Ahmanson Trailhead Rattlesnake
Big Southern Pacific Rattlesnake at Ahmanson Ranch
Stuck in the Drive-Thru
September and October are Tarantula Months!
If It Looks Like a Hummingbird and Flies Like a Hummingbird…