The preserve protects one of the last remaining high-quality examples of Alluvial Fan Sage Scrub in Southern California.
Etiwanda Falls is a perennial feature, though its volume fluctuates significantly based on seasonal snowmelt and precipitation.
The area serves as a vital biological corridor between the San Gabriel Mountains and the Chino Basin.
The Riverside fairy shrimp, an endangered species, inhabits the preserve's ephemeral vernal pools.
The trails were designed specifically to prevent fragmentation of the sensitive sage scrub habitat.
Geologically, the preserve sits on a series of alluvial fans formed by sediment deposits from mountain streams.
The North Etiwanda Preserve is a 1,200-acre protected area in the San Gabriel Mountain foothills dedicated to conserving the Alluvial Fan Sage Scrub habitat. The primary attraction is the 3.3-mile round-trip trail leading to Etiwanda Falls, which features a seasonal waterfall fed by runoff from the San Gabriel Mountains. This ecosystem serves as a critical habitat for the endangered Riverside fairy shrimp and the coastal California gnatcatcher. The preserve is characterized by its rocky terrain, expansive valley views, and minimal canopy cover. Established as part of a multi-agency mitigation plan, it restricts human activity to designated paths to protect endemic flora and fauna. Visitors must navigate moderate elevation changes while observing strictly enforced trail boundaries.
The rock outcropping overlooking the waterfall and the distant valley landscape.
Bring significantly more water than you expect to drink, as the trail is fully exposed to direct sunlight.
Trekking poles are highly recommended due to the loose, rocky surface of the upper trail section.
Check local weather reports for high wind warnings, as the Santa Ana winds can impact safety and trail conditions.
Do not attempt the hike during the middle of the day in summer; heat exhaustion is a high risk due to the lack of shade.
The preserve may close temporarily during periods of extreme fire danger or heavy storm activity.
Stay strictly on marked trails at all times; dogs must be kept on a leash; pack out all trash.
