Category Archives: trails|smmc open space

Las Virgenes – Cheeseboro – Palo Comado Loop

Las Virgenes Canyon sunrise

The trail was exposed and sweat was dripping from the brim of my cap like a faucet with a worn out washer. Expecting a warm day I had started my run early — before sunrise — but that had not been early enough. It was 8:30 am and the temperature was already over 90°F. It was not only hot, it was humid. Monsoon clouds were scattered across the sky, but somehow the sun was dodging all of them. It was disturbingly familiar.

Even if the weather wasn’t perfect, the run was a good one. I was doing a loop from the Las Virgenes Trailhead of Upper Las Virgenes Canyon Open Space Preserve. There are two trails here — the main trail which follows Las Virgenes Creek north up the canyon, and a power line service road (about 50 yards south of the first) that climbs out of Las Virgenes Canyon and leads west to the Cheeseboro Ridge Trail.



I had taken the power line service road, and worked west over to the Cheeseboro Canyon trailhead, then up the Modelo Trail and over to Palo Comado Canyon. Now I was a couple of miles up-canyon on an unmaintained, but well-used, single track trail that links the Palo Comado fire road with the Sheep Corral Trail. Once on the Sheep Corral Trail I could follow it east past Shepherds’ Flat all the way back to Las Virgenes Canyon.

There would be some relief from the heat once I reached Las Virgenes Canyon, but this was really a run better done on a cool day. On the calendar Autumn was just days away. Southern California or not, eventually the weather would cool. The development of a weak to moderate El Nino had stalled, but nearly all forecasts indicated further development was imminent. Maybe a little rain wasn’t too many weeks away.

With an elevation gain of only 1800′ over 14 miles this route includes long stretches of faster-paced trail — both single track and dirt road — but there are some good hills as well. Many variations are possible. This Park Service PDF shows the trails in the area.

Some related posts: Upper Las Virgenes Canyon – Cheeseboro Ridge Loop, Owl Feather on the Modelo Trail, Las Virgenes Creek Near the Sheep Corral Trail

Bulldog Recovery Run

Marine layer in Simi Valley from Sage Ranch Park

I like to do a short recovery run the day after a 50K. An early morning run helps smooth out the tweaks and twinges of the race, and a lingering runner’s high brightens the senses and the day.



Weather-wise, the timing of the Bulldog 50K/25K was perfect. Yesterday was one of the coolest of the cool wave. Today temps were already on the way up. Here’s a chart comparing the air temperature in the shade at the Malibu Canyon RAWS (near Tapia Park) for the last seven Bulldog races, and a similar chart with the fuel temperature in the sun.

As at the top of the Bulldog climb, vaporous clouds drifted among the rocks, trees and chaparral at Sage Ranch Park. Heavy dew coated the plants along the trail, and the night-cooled droplets felt like splashes of ice water on my legs. Below, a pillowy layer of clouds filled Simi Valley. I jogged along the trail, legs tired, but feeling good.

Morning Thunder, Chaparral Rain

I didn’t catch the late evening update of the forecast when the 20% chance of showers and thunderstorms in the San Fernando Valley was extended into Saturday morning, but the raindrops on my car and the towering cumulus to the west were pretty good clues that I might get wet on my run.

A friend was doing the Baldy Run to the Top course, but one week out from the Mt. Disappointment 50K I’d opted for something a little more moderate — a 13.1 mile keyhole loop through Cheeseboro Canyon from the Victory trailhead at Ahmanson Ranch. The Mt. Disappointment course has a lot of elevation gain, and today the 1,300′ of gain/loss on the Cheeseboro Canyon run sounded a lot better than the 3900′ gain/loss on Baldy!

It sprinkled on and off as I made my way out East Las Virgenes Canyon and up Las Virgenes Canyon. A little while after turning onto the single track that leads to Shepherds’ Flat, the rain drops grew bigger and soon after I was running in a shower.

It is a rare thing to run in the rain on an August morning in the Simi Hills. It added a dimension not often found here in Summer, dampening sun-parched chaparral and refreshing its scents, smells and colors.

I reached the junction at Shepherds’ Flat and turned south onto the Cheeseboro Canyon Trail. As if signaling my turn, thunder rumbled through the hills behind me. It sounded like the active cell was a few miles to the north — probably over Simi Valley. The running in upper Cheeseboro Canyon was outstanding. I was there early and the main wave of cyclists were still working their way up the canyon, after waiting for the Cheeseboro parking lot to open.

The rolls of thunder were now growing more distant, and from time to time a shaft of sunlight would break through the clouds. Along the trail laurel sumac and Datura had captured small puddles of water in the V of their leaves, and occasionally the sun would glint from one leaf and then another.

With the showers and clouds, the temperature was almost chilly. If only we could have cool weather for Mt. Disappointment! Not likely — the MRF medium range computer model was forecasting a heat wave in Southern California over the next several days. Inland temps were forecast to peak race day (Saturday) with temps at the lower elevations of the San Gabriel Mountains reaching around 100 degrees. Some clouds and an afternoon thunderstorm were a possibility, but the degree to which monsoonal moisture would be pushed up into Southern California was a big question mark.

Update Wednesday, August 8, 2012. Measured some temperatures on a run at Ahmanson yesterday. Temperatures generally ranged from about 103°F to 108°F. There was a pretty good breeze with a lot of mixing. These were temps out in the open a few feet off the ground. Even with the breeze ground temps in full sun were over 120°F. Today’s 12z and 18z NAM shows valley temps peaking on Friday, with a little cooling on Saturday. An increase in monsoonal moisture is forecast into Saturday above about 10,000′, but dewpoints/humidities below that level remain relatively low. Hot temperatures (95°F to 105°F) are still forecast for Saturday in the lower elevations of the San Gabriel Mountains.

Update Tuesday, August 7, 2012. Yesterday Woodland Hills tied the record high temperature for the date of 108°F. This morning’s NAM weather model forecasts warming to continue inland through at least Friday, and this morning’s MRF still has the hottest inland temps on Saturday. The amount of monsoon moisture is still uncertain. The high pressure system is in a position that could transport moisture into Southern California, but so far the models are not forecasting a strong monsoonal flow.

Some related posts: Las Virgenes Creek Near the Sheep Corral Trail, Classic Cheeseboro Canyon