Back in March 2020, I hiked the  Powder Canyon Trailhead, located roughly five miles north of Fullerton, off Harbor Boulevard in the Puente Hills Preserve. Just west of Powder Canyon, off Colima Road in Whittier, is another network of trails also managed by the Puente Hills Habitat Preservation Authority called Arroyo Pescadero, which shares similarities to Coyote Hills here in Fullerton.

Open to the public, the Arroyo Pescadero Trail is another home for chaparral, coastal sage scrub and the endangered coastal California gnatcatcher. The area is made up of three pathways: the Bob Henderson Loop Trail (2 miles), the Arroyo San Miguel Trail (1.8 miles), and the Deer Loop Trail (0.8 miles), all of which are worth the hike for their tranquility and biodiverse ecosystems.

Arroyo Pescadero Trailhead off Colima Road in Whittier offers ADA access.

Similar to Coyote Hills, the Arroyo Pescadero area of the Puente Hills Preserve is the site of a former oil field, and today’s pathways were once oil company roads. Hikers have to literally walk on parts of crumbling roadways that were once used for transporting oil drilling equipment. Formerly owned by Chevron, these hillsides in Whittier were used for extracting oil for decades until the late 1980s, according to a July 2021 hiking guide written by Melissa Mora Hidalgo for the online publication,  L.A. TACO.

Fortunately, this once-depleted landscape has been restored and is perpetually protected as wilderness due to the efforts of the Puente Hills Habitat Preservation Authority, which acquired the land and spent years painstakingly restoring the coastal sage scrub, oak and walnut woodlands, riparian forests and chaparral.

“Habitat restoration eliminates non-native weeds, and replaces or restores vegetation to its natural state of native plants,” writes the Habitat Authority. “This process increases the biological diversity of the hills, increasing the health of the ecosystem as a whole.”

It wasn’t until 2002 that the Arroyo Pescadero Trailhead was constructed and opened to the public. Today, for the size and scope of the trails found at the Arroyo Pescadero part of the preserve, the parking lot seems rather small; the good news is that this allows only a handful of people on the trails at one time.

Arroyo Pescadero Trailhead on Colima Road in Whittier.

To arrive at the entrance from Fullerton, I drove down Rosecrans, turned north on La Mirada Blvd., which eventually turned into Colima Road. The turnoff for this trailhead can be found a few miles north of Whittier Boulevard. However, there were no parking spaces open when I visited on a weekend. When I returned early on a Monday, there were a few spots available.

The gated entrance area has a portable restroom, a drinking fountain and ADA access. The preserve is closed from sunset to sunrise. Signs posted on an information board at the entrance warn of poison oak, ticks, rattlesnakes, mountain lions and bobcats.  It’s worth reading the signage because dogs and bicycles aren’t allowed in certain parts of the preserve. From here, visitors can choose either to walk up a set of wooden stairs or take a ramp, both of which connect to the semi-paved two-mile loop that is the Bob Henderson Trail.

Smaller pathways branch off the uphill portion of the Henderson path and lead to scenic overlook points, which provide views of both L.A. and Orange County cityscapes.  At the peak of the Bob Henderson Trail, I encountered a painter with a canvas and an easel. He was contemplative and quietly painting the picturesque view.

A surprisingly green valley could be seen while looking between the canyon hillsides, which were covered in dry vegetation. The hike descended downhill from this point and was relatively wide all the way through, so families can easily access the area.

Eucalyptus trees near the turnoff to the 0.8 mile Deer Loop Trail.

Once the Bob Henderson Trail hit the arroyo, it looped across the surrounding hillsides. Along the way, I spotted several brown cottontail rabbits crossing the path in front of me, as well as a wide variety of bird species that were very active early on an overcast morning.

Eventually, the pathway hit a crossroad where it connected with the Deer Loop Trail. It’s at this point that there’s a noticeable contrast between the restored and non-restored sections of the preserve. The Bob Henderson Trail has rich vegetation with many California pepper trees, while the Deer Loop Trail is mostly dry vegetation with Eucalyptus trees, which were first planted in California in the 1850s.

​According to signage from the  Habitat Authority, “chosen for its rapid growth rate, Eucalyptus was planted in the hopes of quickly providing railroad and general construction material, wind breaks, and fiber. At this site, the Eucalyptus was planted by the previous land owner, an oil operator, to screen their oil wells. Unfortunately, due to competition from the Eucalyptus, many naturally occurring species were unable to seed here and are now gone. Eucalyptus is also a highly flammable species. Oil found in the bark and leaves is volatile, creating a greater fire hazard in an already dry Coastal Sage Scrub environment.”

Much like Fullerton’s Coyote Hills,  the Arroyo Pescadero Trailhead is a rare green space that offers peace and quiet from city life, but is still undergoing restoration in an effort to bring back native species of plants and animals. If you do decide to hike here this summer, wake up super early and arrive in the morning with a hiking stick, a large Hydro Flask filled with water, and a sun-protective hat.

Arroyo Pescadero is located at 7531 S. Colima Road in Whittier.

The Bob Henderson Loop Trail in the Arroyo Pescadero area of the Puente Hills Preserve is two miles long and wide enough for families to walk on.

The Arroyo Pescadero area of the Puente Hills Preserve above Whittier is the site of a former oil field that is now home to several habitat restoration projects.

Scenic view of L.A. County smoggy cityscape and Arroyo Pescadero wildlife corridor from high elevation off 2-mile loop trail in the hills above Whittier.

Restored native plant species thrive near a lookout point off the Bob Henderson Loop.

My dad observes native plants that have been restored along a curve in the Bob Henderson Loop Trail.

My dad admires the green vegetation in the valley below the canyon off the two-mile Bob Henderson Loop Trail.

A landscape painter makes art at a scenic vista near a rammed earthen amphitheater at the top of the Bob Henderson Loop Trail.