Category Archives: nature

Rocketdyne – Sage Ranch Pollution

Refuse in the creek bed between Santa Susana Field Laboratory and Sage Ranch.

Updated 02/21/08.

In late September 2005, the Topanga Fire burned many thousands of acres in the Simi Hills. One of the side effects of the fire was to reveal the extent of the refuse that was in the creek bed that runs east-west between Boeing’s Santa Susana Field Laboratory and Sage Ranch Park.

The rusty storage drum in the photograph above is just one of several drums and other refuse I saw partially buried in the sediments of the creek.

These photographs are from a run at Sage Ranch on October 21, 2005. In March and April 2006 some restoration and other environmental work was done in this area, and some of the refuse pictured may have been removed. The area is recovering from the fire, and the section of the creek bed pictured is now so overgrown it is difficult to tell.

This topographic map shows the location of the creek relative to Sage Ranch and Rocketdyne, and (in red) the Sage Ranch loop trail. The creek is part of the Meier Canyon drainage, which flows into Simi Valley.

Here are some additional sources of information regarding environmental issues in the area:

Department of Toxic Substances Control Santa Susana Field Laboratory Site Investigation and Cleanup Web Site

Department of Toxic Substances Control Project Documents: Santa Susana Field Laboratory

Boeing: About Us – Environment – Santa Susana Field Laboratory

Wikipedia: Santa Susana Field Laboratory

Milk Thistle Seed Heads

Milk Thistle (Silybum marianum) seed heads.

A native of the Mediterranean, Milk Thistle is an invasive weed that appears to be increasingly profuse in roadside areas of Upper Las Virgenes Canyon Open Space Preserve. Generally considered detrimental in the wild, the plant has been used medicinally for at least 2000 years, and is cultivated in Texas, Canada and Argentina.

According to the Washington State Noxious Weed Control Board, Milk Thistle (Silybum marianum) produces about 190 seeds per flower, and over 6000 seeds per plant. Dense stands are reported to produce 1.4 million viable seeds and four tons of vegetation per acre! Here is a closer look at an individual Milk Thistle seed.

This photograph was taken on a run at Ahmanson Ranch on July 13, 2006. The posting Convoluted includes a photograph of the white-veined leaf, and a photo of a dense stand of Milk Thistle in Las Virgenes Canyon. Additional information regarding Milk Thistle, including its history, laboratory studies, clinical trials, and adverse effects can be found in the National Cancer Institute’s Milk Thistle (PDQ®).

Valley Oak Savanna

Valley oak savannah on the north slopes of Laskey Mesa.

What a difference a week makes! At about 10:00 in the morning, when this photograph was taken, the temperature at a nearby weather station was a pleasant 78°F. Just a week before, the mid-morning temperature had been a blazing 104°F, and neighboring Woodland Hills had just set an all-time record high of 119°F!

The photograph is of valley oak savanna on the north slopes of Laskey Mesa in Upper Las Virgenes Canyon Open Space Preserve (formerly Ahmanson Ranch). As mentioned in the posting Laskey Mesa Oak, this area was burned in the 2005 Topanga Fire. If you look closely, the condition of the trees varies widely. Some have full crowns; some partial crowns; and some are nearly bare.

Headed back on the Ahmanson “main drag,” I had done a keyhole loop through Cheeseboro Canyon, starting at the Victory trailhead. The 13 mile route is slightly shorter than the Bulldog Loop, and has less than half the elevation gain. Following several strenuous weeks, the idea was do some tempo and not too much climbing.

Here’s a Google Earth image and Google Earth KMZ file of a GPS trace of the loop, and links to trail maps for Upper Las Virgenes Open Space Preserve and Cheeseboro/Palo Comado Canyons.

Related post: Ahmanson Blue Oak