The Rancho La Costa Preserve, located in the cities of Carlsbad and San Marcos, is a popular destination for both hikers and mountain bikers. Situated between Batiquitos Lagoon and Lake Hodges, the preserve serves as an important connector for these two bodies. The 1600-acre preserve with its 15 miles of trails is managed by the Center for Natural Lands Management. Most trails allow dogs on leashes except the Copper Creek Trail and Whiptail Loop.
While known for a variety of interesting trails that explore the coastal-sage-scrub-covered hillsides, few of its visitors are aware of the area’s history of copper mining that spanned nearly 100 years. From mid-1800 until just after the end of World War I, the less-visited Copper Creek section of the preserve was the site for several copper mines. These mines were closed and blasted shut by 1925, yet there is still ample evidence to be found of their existence for those that know where and what to look for. Ruins of mining facilities are partially hidden by chaparral and even in the creek itself.
The first half-mile of the trek is on a wide service road running under some impressive power lines. At 0.1 mile, the trail will pass the junction for the Switchbacks Trail to your left. There will be several other unmarked trails heading uphill on the left but continue on the service road. At the 0.5-mile mark, there is a kiosk and the entrance to the Horned Lizard Trail on the left. After ascending this trail for less than 100 yards, the intersection of the Copper Creek and Whiptail Loop trails lead off to the right. Note that dogs are not allowed on these trails due to the sensitive nature of the habitat.
Before continuing on, be sure to turn around and enjoy the vista looking west toward Batiquitos Lagoon and the ocean in the distance. Continue for 0.2 mile until the Copper Creek and Whiptail trails diverge. Stay to the right to keep on the Copper Creek Trail. At approximately 0.75 mile, the trail descends into Copper Creek ravine. Notice the change in vegetation. The sparser and generally lower vegetation of the coastal sage scrub community begins to give way to the denser, larger plants of chaparral and finally to the water-loving riparian community at the ravine bottom and along Copper Creek itself. If there have been recent rains, you may hear the sounds of Copper Creek as it rushes from its source in the Escondido Watershed (which begins above Lake Wohlford in Bear Valley) to join Escondido Creek before eventually emptying into the San Elijo Lagoon several miles to the west.
At just over 1 mile, the trail crosses over the foundations of an old mine. You have now reached the realm of the mining operation known as the Encinitas Mining District. The mounds of gray, sandy material visible on both sides of the creek are the tailings from these mining operations. If you look carefully, samples of the copper ore that was once extracted here may still be found. While copper is naturally reddish in color, it takes on a beautiful blue-green patina as it oxidizes. Though one may be tempted to collect samples, do not — leave all items where found so that others may enjoy them. Continuing up the trail for another hundred yards, there is old dam spanning the creek. The water once impounded behind the dam was used in the processing of the copper ore. This makes a delightful location for lunch or just enjoying the sounds of the creek as it flows past. At this point, either turn around for a 2-mile round-trip back to where you are parked or continue another 0.5 mile until you reach the trailhead that marks the limits of the preserve. If inclined to reach a viewpoint, take the East Connector Trail (0.25 mile before the edge of the preserve) and climb 400 feet in about 1 mile to the water tank. For those wanting to get in even more mileage, the Whiptail and Horned Lizard trails explore other sections of the preserve.
Distance from downtown San Diego: About 35 miles (Carlsbad). From I-5N, exit east at La Costa Avenue and continue 4 miles. Turn left on Rancho Santa Fe Road, then proceed 0.8 mile to Camino Junipero and turn right. Go 0.3 mile, then take another right onto Avenida Maravilla and park since there is no parking on Camino Junipero — please be respectful of neighborhood residents. Carefully cross Camino Junipero and go south about 200 feet to the La Costa Junipero trailhead, where the power lines cross the road.
Hiking length: 2 miles in and out.
Difficulty: Easy with approximately 200 feet of elevation gain/loss. The hike may be extended by including other trails as desired. The trails are well maintained and marked. Watch for mountain bikers who regularly use the designated trails. No dogs on the Copper Creek and Whiptail trails. No facilities.