- Location: Fallsview Park, San Marcos. From the south, take I-5 to the Leucadia Blvd. exit. Head right and go a total of 5.6 miles (Leucadia becomes Olivenhain Rd. and then Rancho Santa Fe Rd). Turn right onto San Elijo Road and go 0.8 mile. Turn right on Fallsview Rd. and park where available. From the north, take I-5 to La Costa Ave. Turn left and go 4.1 miles to Rancho Santa Fe Rd. Turn left and go 1.7 miles to San Elijo Rd. Turn right and go 0.8 mile to Fallsview Rd. Park where available. From the 78 Freeway, take the Rancho Santa Fe exit and head south for 4.1 miles (turn left if you are coming from the east; right if you are coming from the west) to San Elijo Rd. Turn left and go 0.8 mile to Fallsview Rd. and park where available.
- Agency: City of San Marcos/City of Carlsbad
- Distance: 4.2 miles
- Elevation gain: 750 feet
- Suggested time: 2 hours
- Difficulty Rating: PG
- Best season: All year but hot during the summer (best after recent rains)
- Dogs: Not allowed (Allowed on other trails in the reserve)
- Cell phone reception: Good
- Water: None
- Restrooms: None
- Camping/backpacking: None
- Recommended gear: sun hat
; hiking poles
- More information: Trip descriptions here, here and here; Yelp page here; Map My Hike report here; preserve map here
- Rating: 6
For a suburban hike in north coastal San Diego County, this loop feels surprisingly adventurous. Highlights include abandoned copper mine remains, a seasonal waterfall, secluded canyon and panoramic views of the area. The hike described below can easily be done in a few hours, but Rancho la Costa’s extensive network of trails provides many opportunities to extend your trip. The directions may sound a little elaborate but the reserve is well signed and the junctions are all fairly intuitive – basically you are making an elongated clockwise loop.
From Fallsview Park, follow San Elijo Road a short distance to the signed trail head. Entering the reserve, you arrive at a junction. Head left (the right fork is the return route). The next half mile may not seem promising as you head through the eastern corner of the reserve on a series of unsigned fire roads, below power lines. Stay right, then left at two junctions before reaching a T-junction at the eastern edge of the park, by a former waste treatment facility (I promise, it gets better). Head right (south), passing by the facility and into Copper Creek Canyon. At about 0.5 mile from the start, you re-enter the reserve.
Immediately the scenery becomes much more appealing as you make your way through the canyon alongside seasonal Copper Creek. Almost all sights and sounds of civilization disappear. Stay right at a Y-junction (0.9 mile) and head deeper into the canyon, crossing the stream twice on footbridges. At 1.2 miles, just as the trail enters the open, look for a path heading down to a pair of small waterfalls that come to life after recent rains. The two cascades are about 8 feet high each. The wider one, farther from the trail, empties into a pool. It’s difficult to safely view this waterfall however; exercise caution if you decide to head out onto the ledge for a closer look.
After enjoying the waterfalls, continue along the Copper Creek Trail. The trail forks and almost immediately rejoins and then reaches a true junction. Bear right and follow the Copper Creek Trail uphill, passing remnants of an abandoned mine, to a junction with the Whiptail Trail (1.6 miles.)
The Whiptail Trail climbs steadily up the south side of the ridge, providing panoramic suburban and ocean views. A mile of climbing brings you to the crest of the ridge. Take a short detour to the high point in the reserve, Denk Mountain, by heading west and climbing another 100 feet in 0.3 mile. At Denk Mountain, you can sit at a picnic table and enjoy a 360-degree view of northwestern San Diego County.
Retrace your steps back to the top of the Whiptail Trail and continue along the fire road. The trail makes an efficient if not terribly scenic descent, dropping 600 feet in a mile to return back to San Elijo Road.
Text and photography copyright 2018 by David W. Lockeretz, all rights reserved. Information and opinions provided are kept current to the best of the author’s ability. All readers hike at their own risk, and should be aware of the possible dangers of hiking, walking and other outdoor activities.  By reading this, you agree not to hold the author or publisher of the content on this web site responsible for any injuries or inconveniences that may result from hiking on this trail.  Check the informational links provided for up to date trail condition information.