• Crestridge Ecological Reserve
  • Crestridge Ecological Reserve


1 to 15 (miles)


Easy to Moderate


Del Mar, CA 92014, USA

Crestridge Ecological Reserve

About this trail

The Crestridge Ecological Reserve has close to 3,000 acres and is one of 16 California Department of Fish and Wildlife Ecological Reserves in San Diego County, preserving a core block of habitats identified by the San Diego Multiple Species Conservation Program. There are lots of possible trails. So many, in fact, we suggest that when you arrive examine the map on the kiosk or take a photo. It's possible to hike over 20 miles and seldom travel the same route.

Make sure to use the official entrance at Horsemill Road. From there, several trails leading east and west radiate outwards. A popular route is the 3-mile Valley View Truck Trail that has less than 500 feet of elevation gain. From the Horsemill Road entrance, follow the dirt road northwest or left through a riparian woodland. As you exit the woods, take the north-most trail to the right, up and into the coastal sage scrub/chaparral habitat. This fire road runs along the north edge of the reserve where there are private avocado orchards that grow down to the urban interface with I-8. At the western edge of the reserve is a heavy, yellow-painted metal gate that is about 3.5 miles from the Horsemill entrance.

To make this a loop hike, turn left or south at mile 1.8 onto a single track and climb. Stay right at forks until you reach a boulder-studded high point at 2.8 miles with stunning views. This also can be an out-and-back or, for the more adventurous, a 4-mile loop. Head east down the single-track trail from the highpoint, taking an old roadway north to a T-junction. To the right the trail eventually leads to the Valley View Truck Trail, heading east and back to the Horsemill Road entrance to complete the loop.

For a simple mile-long hike, start east of the James Hubbell-straw-bale-built shelter and head northeast up a signed trail. At the top, head left or west at the Y-junction to an overlook of east El Cajon and the San Diego River watershed to the north. The trail loops back down to the southwest past a large-scale native grassland restoration project with hundreds of protective plant cones. The trail ends at the oak grove.

Before you go, check to ensure the trail is open. More detailed information about plants, wildlife, history, and geology of the area can be found at USFWS Crestridge Ecological Reserve.

What you’ll see

Vegetation types found within the reserve include coastal sage scrub, chaparral, oak woodlands with coast live oaks and Engelmann’s oaks, as well as riparian and grassland. You may climb past the blackened woody remains of the 2003 Cedar Fire. It is also home to hawks, owls, woodpeckers, gnatcatchers, southern mule deer, coyotes, bobcats, foxes, mountain lions, horned lizards, and rattlesnakes. To top it off, there are beautiful views of El Cajon, Lake Jennings, and even the Pacific Ocean on a clear day.

Two rare plant species, Lakeside-lilac and thornmint, plus insects of concern that include Hermes copper butterfly and Harbison's dun skipper are within the reserve. Thornmint (Acanthomintha ilicifolia) is a small, state-listed endangered and federally-listed threatened mint found where there is gabbro or calcareous (clay-like) soil openings in coastal sage scrub, chaparral, grasslands, and occasionally near vernal pools. This annual herb is endemic to coastal San Diego and northern Baja California. It is less than 1.5 feet tall with funnel-shaped white flowers tinted purple to pink with two lips, with the upper lip smaller than the lower lip. It has small oval serrate leaves and blooms April through June. It has lost 90% of its habitat, mainly due to development. Of the 32 remaining populations, 28 are on private lands and only four are covered by the Multiple Species Conservation Program. This reserve is one of those four.

Organizations like the Earth Discovery Institute and Endangered Habitats Conservancy are in a multi-year habitat restoration effort in this area that has included over 20,000 students. Enjoy their work!


From I-8 go south on Greenfield Drive for 0.5 mile. Turn left on La Cresta Road. Go 3.1 miles. Turn left onto Mountain View Road. Go 1.2 miles. Turn left on Horsemill Road. Go 0.6 mile. Park at the end of street at signed entry to the reserve. Trailhead GPS: N32.82823, W116.85637

Explore more

Looking for more great hikes? Check out our Canyoneers page or purchase the book, Coast to Cactus: The Canyoneer Trail Guide to San Diego Outdoors.

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