Pasadena features extraordinary open space corridors along both its western boundary at the Arroyo Seco, and its eastern boundary at Eaton Canyon and Eaton Wash. The Arroyo is home to the historic Rose Bowl, but the natural crown jewel of this area is the city-owned 300-acre Hahamongna Watershed Park. Hahamongna provides a natural gateway to the vast open space areas of the Angeles National Forest with its interconnected system of hiking trails and prime oak woodland.
In Eaton Canyon, Pasadena hosts the Eaton Canyon Nature Center. The nature center is an entry to the Eaton Canyon Natural Area, a 190-acre zoological, botanical, and geological nature preserve situated at the base of the San Gabriel Mountains.
These areas are already protected as public open space by the city or by Los Angeles County, but great open space acquisition and preservation opportunities remain in the city’s western canyonlands, most of which are still privately owned. A partnership between the City of Pasadena, the Santa Monica Mountains Conservancy, the County of Los Angeles, and neighbors led to the preservation of the 20-acre Annandale Canyon in 2009. The Arroyos & Foothills Conservancy is working with these and other partners to continue to preserve the roughly 200 acres of remaining open space land in this corridor.