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

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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

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Caught in a Thunderstorm on Rocky Peak

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Sun and gathering clouds on Rocky Peak Road before a strong thunderstorm
Sun and gathering clouds on Rocky Peak Road

Rocky Peak Road is an exceptionally popular hiking and biking trail that starts at Santa Susana Pass, on the north side of the 118 Freeway. Regardless of the time of day or weather I ALWAYS see someone on this trail.

The plan for this afternoon’s run was to do an out and back on Rocky Peak Road to the top of the Chumash Trail (3.8 miles) or to Fossil Point (4.8 miles).

Another runner was finishing their workout as I started up the initial steep climb. Glistening in the warm sun, runoff from yesterday’s storm streaked some of the sandstone rocks, and ephemeral streams gurgled in the ravines and gullies.

Thanks to the sandstone geology, the dirt road wasn’t as muddy as most other local trails would be. Although heavily eroded from numerous Winter storms, it was still near the top of my list of places to run during periods of wet weather.

In the aftermath of yesterday’s storm the weather was spectacular. The temperature was warm enough to run in shorts and short-sleeves but still comfortable chugging up Rocky Peak Road’s steep hills. Puffy cumulus clouds filled the sky, creating postcard views at every turn.

Clouds developing over the San Fernando Valley (thumbnail)
Clouds developing over the San Fernando Valley. Click to enlarge.

More focused about getting up the hill than any weather concerns, I continued past the top of the Hummingbird Trail and through a gap in the rocks to a section of road with a good view of the San Fernando Valley and San Gabriel Mountains.

I’d been in a situation similar to this several times on Rocky Peak. As a storm moves east from Los Angeles, energy circulating around the low can sometimes result in “back-door” precipitation. In this scenario, clouds build-up over the mountains to the north and then drift over the San Fernando Valley, producing showers — and sometimes — thunderstorms.

But today’s scenario was a bit more complicated. A much larger area, extending east to the San Gabriel Mountains, was rapidly destabilizing. What had been a picturesque sky at the start of the run was now congested and ominous. The question wasn’t so much if it was going to rain, but if a thunderstorm was going to develop.

As I continued up the road, the sky darkened, the temperature cooled, and the wind became more gusty and fitful. A little chilly, I pulled on my arm sleeves. I laughed nervously as I mistook the roar of a passing jet for thunder. That was a jet, right?

When people say they are “doing Rocky Peak,” they are often referring to a high point on Rocky Peak Road that is west of the actual peak and about 2.4 miles from the trailhead. The final climb to this high point is a good one — gaining about 450 feet over three-quarters of a mile.

The road on this stretch is oriented in such a way that the terrain hides the view to the north. I was anxious to get to the top of the hill so I could get a better idea of what the weather was doing. As I worked up the road, I would occasionally feel the cold splash of a raindrop on one leg or the other.

Doppler radar of strong thunderstorm over Rocky Peak (Thumbnail)
Doppler radar of strong thunderstorm over Rocky Peak. Click to enlarge.

Nearing the top, I thought, “I may get wet, but at least there’s been no thunder.” Within seconds of that proclamation, and as I reached the highest point, there was a long, loud, crackling peal of thunder.

One look at the sky and all thoughts of continuing to the Chumash Trail were gone. I turned around and started running down the hill, hoping to avoid the worst of the storm.

First one pea-sized hailstone hit the ground, then another, and then a sleety barrage of rain and hail poured from the sky. Instantly soaked, I shuddered as thunder echoed overhead and cold rain ran down my back. Muddy water flowed in rivulets down the sodden road and I cautioned myself to run fast, but not too fast.

I didn’t expect to outrun the storm, but hoped I might move to a part of it that was less intense. And that’s what happened. As I descended, the deluge gradually diminished. Most of the activity seemed to be behind me and a little to the east.

Severe thunderstorm over Porter Ranch - Northridge area (Thumbnail)
Severe thunderstorm moving into the Porter Ranch – Northridge area. Click to enlarge.

By the time I got down to the Hummingbird Trail, it was only sprinkling. The strong cell that had been over Rocky Peak had drifted southeast, and was now over the Porter Ranch – Northridge area.

National Weather Service Doppler Radar tells the story. At the start of the run there were scattered, mostly weak echoes. At 3:06 pm, as I was starting up the last long hill, a cell northwest of Rocky Peak was developing and drifting southeast. Over the next 16 minutes the cell continued to move southeastward and strengthen, and at 3:22 pm was over the Rocky Peak area. I turned around and started down as the cell moved into that area.

The cell over Rocky Peak continued to strengthen, and at 3:39 pm had drifted over the Porter Ranch – Northridge area. At 3:44 pm the NWS issued a Severe Thunderstorm Warning for Western Los Angeles County.

Here are a GOES-18 satellite loop and Doppler Radar loop that show the development and track of the Rocky Peak thunderstorm.

Some related posts:
– Rainy Weather Running on Rocky Peak Road
– Running Between Raindrops: Chumash Trailhead to Rocky Peak
– Thunderstorm

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Trippet Ranch Loop, Musch and Garapito Trails – February 2024

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Mountain bikers at the Hub in Topanga State Park
Mountain bikers at the Hub

It’s uncommon to have back-to-back Rain Years with 20+ inches of rain in Los Angeles. During Rain Year 2022-2023, Downtown Los Angeles (USC) recorded 28.4 inches of rain — about two times normal. This rain year Los Angeles has already had about 21 inches of rain, so another big year is in progress.

Curious to see how the trail conditions compare to last year, on February 17th and 25th I ran the Trippet Ranch Loop in Topanga State Park.

The big surprise was that the fire roads on the loop — Fire Road #30, Eagle Springs Fire Road, and a short section of Eagle Rock Fire Road — generally fared better than last year. Fire Road #30 had some damage along it’s shoulder, but I did not see the numerous mudslides along these roads like last year.

Wet and muddy section of the Musch Trail. February 2024. (Thumbnail)
A little mud on the Musch Trail.

The news on the trails was divided. One of the more unusual events occurred where the Garapito Trail crosses the east fork of Garapito Creek. A mudslide from a gully on the northwest side of the creek crossed the creek, and left a pile of debris on the trail. The stream may have been dammed by mud and debris for a short time. Farther up the trail, about a half-mile from Eagle Rock Fire Road, a section of the trail collapsed in a slide.

The Musch Trail was very muddy and wet in the usual places. There were a couple of slides along the trail, but all things considered, the trail was in OK shape. The Bent Arrow Trail remains closed as a result of previous storm damage.

Last year, the bloom of bigpod Ceanothus was well underway in early January. This year the bloom began about a month later but is now happening in a big way. Greenbark Ceanothus is also starting to bloom. Some peonies were blooming on an east-facing slope of the Garapito Trail, and a Fuchsia-flowered gooseberry was in bloom near Fire Road #30.

Here are some photos taken on these two runs.

Some related posts:
– Popular Trails in Topanga State Park Damaged by Winter Storms
– Wettest 14 Months in Los Angeles in 134 Years
– Rainy Season Trail Running on the Backbone Trail

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Wettest 14 Months in Los Angeles in 134 Years

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Los Angeles Basin from Temescal Lookout
Los Angeles Basin from Temescal Lookout

With over 45 inches of rain reported, the 14 months (424 days) ending February 22, 2024, have been the wettest in Downtown Los Angeles in 134 years.

To put this in perspective, this is more than three times the amount Los Angeles would see in a “normal” year.

The wettest 14 months on record for Los Angeles occurred during late December 1888 to early February 1890, when about 47 inches of rain was recorded.

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Rainy Season Trail Running on the Backbone Trail

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Rock formations below Triunfo Lookout, with the Channel Islands in the distance. From the Etz Meloy section of the Backbone Trail.
The Backbone Trail contours around Triunfo Peak (on the right) above the rock band that extends across the photo. The Channel Islands are in the distance.

The Backbone Trail between Encinal Canyon and Mishe Mokwa is one of the must-do sections of the 68-mile trail. Engineered to be multi-use, this exceptionally scenic stretch of the Backbone Trail is popular with riders, hikers, and runners alike.

Chaparral Currant (Ribes malvaceum) blooming along the Backbone Trail (Thumbnail)
Chaparral Currant

It’s also a pretty good place for a trail run after rainy weather like we’ve had this February. Although the parking lot at the Encinal Trailhead was quite wet this morning, the  Backbone Trail was in decent shape most of the way to the Mishe Mokwa trailhead. There were a few muddy and wet spots, but it was generally easy to work around them. And I didn’t have to change my shoes before driving home.

The out & back run worked out to about 21-miles, with a surprisingly moderate gain/loss of about 2500′. The weather and visibility were excellent. Striking rock formations and the Channel Islands could be seen from one side of Etz Meloy Mtwy fire road, and snow on Alamo Mountain and other Ventura County peaks from the other side.

On the way back, as I was working up the long hill on the northwest side of Triunfo Lookout, a descending mountain biker commented that a large group of bikers were at “the corner.” The overlook at this prominent switchback has a wide-ranging view of Mishe Mokwa, Boney Mountain, and Sandstone Peak, and some prefer to turn around here. This variation is about 3.5 miles shorter (round-trip) than dropping down into the canyon and going all the way to Mishe Mokwa.

Explore the scenery and terrain on the Backbone Trail of this out-and-back trail run and hike from Encinal Canyon to Mishe Mokwa using our high resolution,  interactive, 3D viewer. The imagery is so detailed, it’s almost like being there! To change the view, use the control on the upper right side of the screen, the CTRL key and your mouse, or touch gestures. Track and placename locations are approximate and subject to errors. Poor weather, and other conditions may make this route unsuitable for this activity. Here’s  an elevation profile of the route.

Some related posts:
– Encinal Canyon to Mishe Mokwa Out and Back Trail Run
– Kanan to Mishe Mokwa and Back
– Kanan to Mishe Mokwa to Wendy Drive
– Night Training for the Backbone Ultra

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East Las Virgenes Canyon After a Seventh Day of Rain

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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