Border Bioblitz – Potrero Peak Trailhead

Difficulty: MODERATE (Rocky areas, steep terrain [about 1K’ elevation gain], little shade) 2.5 miles roundtrip (4.0 km) Ticks are a high probability – prepare accordingly.
Plant knowledge: Amateur to Professional
Access: Open to all, no charge for field trip.
Required fees: None – Roadside Parking.
Amenities: Restrooms are available at Potrero County Park and at some services nearby.
Dogs: Not Allowed on County trails.

Bring: Water, lunch, snacks.

[EXTREME TEMPS above 90oF (32oC) or forecast for Heavy Rain / flash floods Will Cancel

This area is north of SR 94 in rural Potrero as the highway winds through the hills from Rancho San Diego to Boulevard. Potrero is about halfway on the route (about 30 miles from Rancho SD / Spring Valley), and only 5 miles from the international border at Tecate, MX. Potrero Peak is a grand view of the south of the County border regions. Plan to have a small lunch around noon at the peak or the turn around point.

The trip itself will be fairly slow-paced at first and geared to take records in iNaturalist primarily as we slowly make our way up the Potrero Peak Trail, stopping for blooming flowers or interesting critters. These records contribute to multiple projects including the City Nature Challenge, Border Bioblitz, and San Diego County Plant Atlas

The dominant habitats are southern undifferentiated ceanothus chaparral, coastal sage scrub, and mature stands of chamise / mountain misery chaparral. The rare plants are gabbro affiliates and clay endemics like southern mtn misery (Chamaebatia australis), Gander’s ragwort (Packera ganderi), Pride of California pea (Lathyrus splendens), Otay ceanothus (Ceanothus otayensis) and delicate clarkia (Clarkia delicata). Mid April should have some nice bloom despite the low rainfall and late storms this year. Sign up and see more info at: Border Bioblitz – Potrero Peak Trailhead, Sun, Apr 13, 2025, 9:00 AM | Meetup

~ Justin Daniel, Rare Plant Surveys Chair