Originally slated for residential development in the 1920s, the land was gradually acquired by the City of Los Angeles between 1949 and 1963 and initially designated Rose Hill Park. Community organizing by Montecito Heights residents helped protect the hillsides from proposed housing developments and freeway construction. In 1968, the City leased the land to Los Angeles County for development as a regional park, later named after former County Supervisor Ernest E. Debs. The park returned to City management in 1994. In 2003, the Audubon Center at Debs Park opened, establishing an important center for environmental education, habitat restoration, and community-based conservation in one of Los Angeles's most densely urbanized regions.

The park is situated within the Arroyo Seco watershed, which drains into the Los Angeles River. It features Southern California black walnut woodland, coast live oak woodland, coastal sage scrub, grasslands, and riparian vegetation, alongside a small artificial hilltop pond. Its extensive trails, native habitats, and ongoing ecological restoration efforts provide critical refuge for urban wildlife, including more than 140 documented bird species, while offering surrounding communities access to nature and open space.