Classic Cheeseboro Canyon

Cheeseboro Canyon

The 13 mile keyhole loop through Las Virgenes and Cheeseboro Canyons from the Ahmanson Victory trailhead is a classic Southern California mix of multi-use fire roads and single track trail.

The segment from Shepherd’s Flat down through Cheeseboro Canyon is especially popular, and on the weekend you’ll find an assortment of hikers, runners, mountain bikers, and sometimes an equestrian group or two. Even on a warm day, the oak-shaded sections of the canyon can be surprisingly comfortable.

Here’s a Google Earth image and Cesium browser View of a GPS trace of the loop, and links to trail maps for Upper Las Virgenes Canyon Open Space Preserve (formerly Ahmanson Ranch) and Cheeseboro/Palo Comado Canyons.

Long Canyon to Simi Peak and China Flat

Wood Ranch Open Space

Wood Ranch Open Space

The fire road was covered with crawling and darting bees — so many I could feel the low, resonating buzz of the colony. Standing in the middle of the buzzing bees, I heard an “Oh crap!” from behind me. A mountain biker — stopped about 20 yards away — explains he’s allergic to bee stings.

We were a little east of the China Flat “T” on the Albertson “motorway” — a fire road in the Simi Hills. Taking advantage of cool, sunny weather in the Los Angeles area, I was doing a course I had not done for years, an out and back trail run from the Wood Ranch trailhead to Simi Peak, with a short circuit around China Flat.

I had taken a short detour to check a small vernal pool hidden in the oaks off the fire road. There are surprising number of these ephemeral water sources in the Simi Hills. They sometimes have water when it’s unexpected, but this time the pool was dry.

The bees on the road were digger bees, ground nesting bees that look like fuzzy honeybees. Like honeybees, males have no stinger. Males swarm over the burrows of females, waiting for them to emerge. Females can sting, but in my experience, and from what I’ve read, are generally not aggressive. Here’s a very short video (from later in the run) of a second colony on the Simi Peak Trail.

Not being able to risk being stung, the mountain biker waited on the side of the road for his buddy to realize he wasn’t behind him anymore. I headed back to the China Flat Trail, and then continued to Simi Peak. Here’s a Google Earth image and Cesium browser View of a GPS trace of my approximately 10.75 mile route.

Note: A mountain biker on the Long Canyon trail told me he had seen a mountain lion in the area earlier in the morning. He was certain that it was a mountain lion, and not a bobcat or coyote.

Photography and inspiration from running and other adventures in the Open Space and Wilderness areas of California, and beyond. No ads. All content, including photography, is Copyright © 2006-2025 Gary Valle. All Rights Reserved.