Overview & significance
The Santa Margarita River Trail Preserve (sometimes called the Santa Margarita County Preserve) lies just north of Fallbrook in northern San Diego County, California. In 2018 The Wildlands Conservancy purchased 1,384 acres of riparian woodlands and chaparral‑sage scrub along a five‑mile stretch of the Santa Margarita River—the last free‑flowing, perennial river in southern California . This addition complemented the existing 221‑acre county preserve operated by San Diego County Parks, creating a protected corridor that links the Santa Ana Mountains with inland San Diego county . The river’s canyon has been recognized since at least the 1990s as an irreplaceable ecological treasure supporting over 500 plant species, 236 bird species, 52 mammals, 43 reptiles, 26 fish, and 24 aquatic invertebrates . Because most southern‑California rivers have been dammed or channelized, the Santa Margarita provides one of the region’s last intact examples of a naturally meandering, groundwater‑recharging river; its waters feed communities in Fallbrook and at Marine Corps Base Camp Pendleton while also sustaining a rich mosaic of habitats .
Positive vibes in a precious place
Visiting the preserve feels like stepping into a living oasis. Lush sycamore, willow and cottonwood groves shade the river; arid hillsides support sage scrub and chaparral; raptors soar overhead while deer and coyotes sip from clear pools . The preserve’s resilience is inspiring: it harbors nearly 1,000 species of plants and animals and over 70 species of special concern, including the least Bell’s vireo, southwestern willow flycatcher and arroyo toad. Surveys by the U.S. Fish & Wildlife Service and California Department of Fish and Wildlife even found rainbow trout and Pacific lamprey living here —rare inhabitants in southern California streams.
Historical & cultural context
Indigenous lifeways and water rights
The Santa Margarita River has nourished the Luiseño/Pechanga people for centuries. The Hidden San Diego guide notes that the river supported villages and agriculture of the Pechanga and Luiseño tribes and that the canyon still contains stone mortars and other cultural remnants. With Spanish colonization and the Rancho Era, much of the watershed was incorporated into Rancho Santa Margarita y Las Flores. In the early twentieth century the Pechanga people lost access to their traditional lands and water. Decades of conflict ensued as water agencies sought to divert flows; the Pechanga Band of Luiseño Indians Water Rights Settlement Act (negotiated between 2008 and 2016) finally quantified the tribe’s reserved water rights and established cooperative management, ensuring a secure water supply while protecting local water districts . Today the preserve honors these indigenous connections by protecting the river and offering educational programs.
Attempts to tame the river
Because the Santa Margarita flows year‑round, it attracted railroad and dam builders. In 1882 the California Southern Railroad tried to route tracks through the canyon, but floods repeatedly washed out the line, and the company eventually abandoned the route . Later proposals sought to build hydroelectric dams. By the 1970s the Bureau of Reclamation considered capturing the river for San Diego’s water supply, but environmental concerns and escalating costs led to cancellation. Grass‑roots advocates pushed for Wild & Scenic River designation in the 1990s and, although no federal designation has been granted, the area remained largely undeveloped . Finally, in 2018 The Wildlands Conservancy purchased the former Santa Margarita Ranch from the Freschet family, permanently protecting the river corridor and partnering with the volunteer Fallbrook Trails Council to maintain 18 miles of trails.
Ecology and conservation importance
Riparian forest and sage scrub
From its headwaters in Temecula and Murrieta creeks, the Santa Margarita River flows about 30 miles southwest through the Temecula Gorge before entering the preserve, then continues through Camp Pendleton to the Pacific. Within the preserve, visitors wander from chaparral and sage scrub on sun‑baked slopes to shady riparian forests along the river. Elevations range from ~320 ft to 1,100 ft, offering micro‑habitats for mountain lions, bobcats, coyotes, mule deer and numerous reptiles . The 1994 Earth Times report emphasised the river’s importance as a biodiversity hotspot, containing the highest density and diversity of riparian bird species in the south coastal river basin .
Endangered species
Several endangered species depend on the preserve’s intact habitat:
- Least Bell’s vireo – this tiny songbird nests in willow‑dominated riparian forests. Habitat loss and parasitism by brown‑headed cowbirds once devastated its populations, but restoration along rivers like the Santa Margarita has allowed numbers to rebound .
- Southwestern willow flycatcher – a subspecies that requires dense riparian thickets. Altered river flows, development and wildfire threaten its nesting sites . The preserve’s mature willows provide crucial breeding habitat.
- Arroyo toad – this small amphibian inhabits sandy streamside terraces and has declined due to non‑native predators, water withdrawals and pollution . Protection of the river’s hydrology helps maintain its breeding pools.
- Southern steelhead – historically, steelhead trout migrated from the Pacific Ocean up the Santa Margarita to spawn. Adult fish were documented as far inland as Temecula in the 1940s . Drought, dams and road crossings blocked migration corridors, leading to federal listing of the southern steelhead as endangered in 1997. Surveys in the preserve have found rainbow trout and lamprey, hinting at the river’s potential for steelhead recovery .
Invasive species and restoration
The preserve’s rich plant communities face threats from invasive species such as black mustard, Malta starthistle, giant reed (Arundo), tree tobacco and tamarisk. The Wildlands Conservancy is working with volunteers to remove these aggressive plants using string‑trimmers, hand pulling and targeted herbicide, helping native plants like oak, sycamore and sagebrush reclaim the riverbanks . Citizen volunteers contribute hundreds of hours each year to this labour of love .
Recreation & visitor experience
Trail network
The preserve offers about 18 miles of non‑motorized trails open to hikers, mountain bikers and equestrians. Two miles of these trails lie within the county‑managed portion , while the remainder traverse the Wildlands property. A trailhead on De Luz Road provides free parking (open 8 am–4:30 pm) with restrooms, picnic tables and an equestrian staging area with horse corrals. Admission is always free. Dogs are welcome on leash, and there is an accessible parking space near the gate .
Recommended routes
- Short loop (3 miles) – From the trailhead, follow the main trail downstream and cross the river at one of the scenic footbridges or stepping‑stones. Enjoy shady riparian forests, small waterfalls and a chance to watch herons and turtles basking on rocks. This loop requires water shoes in winter when flows are higher.
- Long loop (6 miles) – Continue downstream to the confluence with De Luz Creek, then climb the hillside through chaparral to panoramic viewpoints before returning upstream. This hike showcases the transition from lush river corridor to dry scrubland .
Trails are multi‑use—hikers should yield to equestrians and share the trail with mountain bikers. Because the preserve’s gate locks at 5 pm, plan to return to the trailhead by 4:30 pm.
Activities and guidelines
Activities include hiking, horseback riding, mountain biking, birdwatching, wildflower viewing and photography. The preserve prohibits swimming, fishing, fires, drones, overnight camping, alcohol and collecting specimens. Visitors may wade across the river at low flows but should avoid deeper pools and respect wildlife. There is no potable water on site; bring plenty of water, wear sturdy shoes and watch for poison oak, rattlesnakes and ticks . During summer, heat can be intense—morning visits are recommended. The preserve occasionally closes after heavy rains; check for updates before visiting.
Education and volunteer programs
The Wildlands Conservancy offers interpretive programs and volunteer days focused on topics like ecology, indigenous culture and invasive‑plant removal. Local schools and youth groups participate in outdoor classes, and the preserve’s staff encourages stewardship through “Leave No Trace” ethics. Volunteers from the Fallbrook Trails Council maintain trail tread and signage, showing how community involvement keeps the preserve vibrant.
Infrastructure & the steelhead bridge project
One of the preserve’s most exciting current projects is the Sandia Creek Drive Bridge Replacement. The existing 30‑year‑old bridge over the river near Fallbrook is flood‑prone and poses the last significant barrier to migrating southern steelhead. In February 2024 the fisheries consultancy FISHBIO reported that CalTrout and partners would restart construction in June 2024 to remove the old bridge and replace it with a climate‑smart steel bridge . Once completed, the new design will allow endangered steelhead to access the entire 29‑mile river corridor, restoring their historic migration route from the ocean to upper tributaries . The project also enhances public safety by eliminating a flooding hotspot and preserving trail access during storms . According to a Wildlands Conservancy update, construction of the new bridge will not close the preserve; a temporary trail will reroute visitors around the construction zone . Once finished, the old bridge will be decommissioned, opening 12 more miles of spawning habitat for the steelhead .
Safety & stewardship tips
- Respect wildlife: Mountain lions, bobcats and rattlesnakes live here. Stay on trails and keep dogs leashed.
- Bring water: There is no potable water; carry plenty, especially in summer heat .
- Leave no trace: Pack out all trash, stay on established trails, and do not disturb historical or cultural artifacts.
- Check for closures: After major storms the preserve may close temporarily; updates are posted by The Wildlands Conservancy.
Conclusion
The Santa Margarita River Trail Preserve is a jewel of southern California—one of the last places where a free‑flowing river still meanders through native oak, willow and sycamore forests. It preserves not only biodiversity but also the cultural heritage of the Luiseño people and the memory of pioneers who once attempted to tame this wild canyon. The preserve invites visitors to celebrate nature through hiking, horseback riding or simply listening to birdsong by the river. Ongoing restoration projects—like removing invasive plants and replacing the Sandia Creek Drive bridge—demonstrate how collaborative conservation can heal landscapes and reconnect endangered steelhead to their ancestral spawning grounds. When you walk these trails, you’re not just taking a hike—you’re participating in a legacy of love and stewardship that ensures future generations can experience the joyful magic of the Santa Margarita River.