Santa Susana Pass State Historic Park & Chatsworth Park South, Simi Hills, Chatsworth, CAFeb. 14, 2009
Exploring one of LA's most unique and undiscovered mountain parks


Santa Susana Pass State Historical Park and its lower neighbor South Chatsworth Park, encompass almost 2 square miles of boulder-covered hills in the northwest corner of the Los Angeles metro area at the Ventura county border. Although the park is near densely populated Chatsworth neighborhoods, the upper parts of the Santa Susana Park are virtually unknown to anyone but a few locals. Just west and north are many miles of mountain wild lands which provide habitat for deer, coyotes, rattlers, even mountain lions.

Chatsworth Park South is a large, manicured lawn area with a recreation center and a pool, a nicer-than-average neighborhood park in a setting of giant old oak trees. At the western edge, several trails lead up boulder-covered foothills to the higher elevations where it becomes Santa Susana Park, with rugged, native terrain of chaparral and scrub oak among colossal sandstone formations.

This hike is about discovering the upper, Santa Susana Pass Park, a half-mile wide swath of rolling, boulder-covered mountainside between an exclusive neighborhood to the south and Hwy. 118 over the Santa Susana Pass to the north.

There are several layers of foothills leading up the mountain, each offering a more expansive view of the San Fernando valley from the Santa Susana to the San Gabriel to the Santa Monica mountains.
Atop one boulder-strewn ridge is a large talus cave. As expected with close proximity to a large metropolitan area, there is an unfortunate amount of tagging on the surrounding rocks, but the view and the amazing geology make up for this.

The highest part of the park is the south ridge of Santa Susana Pass, from where there are dramatic views of Rocky Peak park and northwest to the Los Padres mountains.The highest point is a 900 ft. elevation difference from Chatsworth Park South.

There is a train line and with two tunnels that divide the park in half, but only a small section of tracks is visable as there are two long tunnels through the mountains. It was only a half mile from the eastern tunnel opening where the devastating commuter train collision of 2008 occurred, one of the worst train disasters in the US.

At this writing, the main entrance to South Chatsworth Park is closed. Apparently part of the park was once a firing range, someone found lead bullets and pursuaded those in charge to close the entire park until they decide the threat is abated, even though only the lower park is affected. If you don't want to climb over the fence, there are other ways to get to the upper park via the surrounding neighborhood.

Trail / Conditions / Maps
The lower part of Chatsworth Park is closed and there is a 6 ft. chainlink fence around it. The upper part, Santa Susana park, can be accessed via surrounding streets. There are numerous trails winding around interesting rock formations at the lower levels. Chatsworth Park South is surrounded on three sides by residential neighborhoods so there are several access areas. However, most of the perimeter is covered in thick overgrowth. It's easy to find a path out when coming back down the mountain, but going in from an adjacent neighborhood will require some scouting. I don't know the easiest legal route to enter the park.

For the easiest way to access the upper Santa Susana park, you'll want to get to an area above the western outlet of the eastern train tunnel, where there is a field of jutting boulders which has become a tagging park for graffitista. From this area, follow a trail north/northwest, past a large, off-limits picnic table area. From there you can find the path that climbs west/northwest up the mountain and passes by the talus cave area.

map of Santa Susana park in relation to Chatsworth Park South
Santa Susana Pass park & Chatsworth Park South

Santa Susana Pass park winds around the  northwest corner of Los Angeles county
Santa Susana Pass park

There is a good trail much of the way up, but to get to the highest part, there is some cross country and rock-scrambling involved.

This isn't a large park and it would be hard to get lost, especially since you can see Chatsworth Park from much of the mountainside, but summer temperatures routinely surpass 100 degrees so bring plenty of water.

Beware of rattlesnakes, ticks and poison oak. It's highly unlikely you'll get to see a cougar, but I saw a group of 8 deer in the upper park.

Directions / Permits / Links
From Hwy. 101 and I-405, take 101 w. to Topanga Canyon Blvd. north. Go about 8 miles, T/L on Devonshire and follow it until it ends at the entrance to Chatsworth Park South, which is gated until a lead abatement situation is resolved. Park on the street.
Highway map to Santa Susan Pass park
map, hwy. Santa Susana Pass park
This is generally a safe residential neighborhood, but be aware there are gangs and thieves in the San Fernando valley so it's wise to stay alert for suspicious characters. Leave nothing visable in your vehicle that looks valuable.
Santa Susana Mountain Park Association Advocacy organization with info and history of the area
NOAA Weather National Weather Service forecast for Rocky Peak area

Santa Susana Pass park above Chatsworth Park South from Devonshire Street
Chatsworth marks the end of the San Fernando valley with boulder-covered mountains.
Mountain lion warning sign
Not your typical neighborhood park sign...

This dirt road is the beginning of the trail on the south side of the park
One of many shady oak trees
Ancient oak trees provide shelter from the heat

There are several levels of foothills, each offering more expansive views of the San Fernando valley and beyond. View northeast shows the Santa Susana mountains that mark the north end of Los Angeles. Note train line at left which tunnels through a hill.

After some grassy foothills, the upper park is rugged, boulder-covered Simi Hills.

East to the train tunnel. A path from the area above the tunnel is a good entry to the upper park.

Dramatic clouds and intense blue skies. East to the San Gabriel front range.

This cloud appeared over the ridge with a silver lining

One of the first of many ridgelines on the way to the top.

South to the Santa Monica mountains

Around this formation is the talus cave and the path to some unique boulders

The talus cave is open both ends.

Atop the boulder ridge are many curious circular holes

Southeast toward Chatsworth. At far right is the Recreation Center at Chatsworth Park.

The rocks have amazing hues and shapes, with lots of these potholes. Looking north to Oat Mtn. above Porter Ranch, CA

Looking west up the mountain to the next ridge. Above and behind that is another ridge, and another.

The clouds made for interesting shadows and light across the northern San Fernando valley.

The "hammer" (my name)

After exploring this formation above the talus cave, and a lunch break, it was time to climb higher up the mountain.

One of the multitude of mini-summits that make up the high park

East across San Fernando valley to the San Gabriel mountains
Rocky Peak park  across Hwy. 118 from Santa Susana Pass park
The highest ridge in the park area overlooks Santa Susana Pass, where Hwy. 118 follows an old stagecoach road west (left) to Simi Valley. North across the highway, the dramatic ridges of Rocky Peak. The entrance to Rocky Peak park is across the overpass. In the distance on the left side is the beginning of the Los Padres mountains. South Mountain has the sheer cliff and north (right) of it is Santa Paula peak.
Santa Susana Pass park and the San Fernando valley of Los Angeles
Only a few locals know about this area in the high back country of Santa Susana Pass park. You'll have the amazing views all to yourself. In the distance are the San Gabriel mountains, left, and Cahuenga Peak above Hollywood, center. To the right, the tall buildings of Warner Center at Topanga Cyn and Hwy. 101 with the Santa Monica mountains behind them.