According to the A. W. Kuchler U.S. Potential natural vegetation Types, Pinnacles National Park has a Chaparral (33) potential vegetation type with a California chaparral and woodlands (6) vegetation form.
The vegetation is about 80% chaparral with woodlands, riparian, and grasslands merged into the chaparral.

In the warmer portions of the park, large areas of greasewood cover slopes, along with manzanita, gray pine, canyon live oak, and blue oak.
Cooler portions of the park have higher proportions of pines and oaks, together with California buckeye, hollyleaf cherry, and coffeeberry.
Willows and elderberries are found along the intermittent streams.
Fire has been a dominant influence on the region's flora, both from natural causes and from intentional intervention by people.
When the region was inhabited by Native Americans, they used fire as a tool to encourage the growth of preferred food sources, and to herd small game during hunting.
 Since the disappearance of native peoples, the hills have become brushier.
According to the A. W. Kuchler U.S. Potential natural vegetation Types, Pinnacles National Park has a Chaparral (33) potential vegetation type with a California chaparral and woodlands (6) vegetation form. The vegetation is about 80% chaparral with woodlands, riparian, and grasslands merged into the chaparral.
In the warmer portions of the park, large areas of greasewood cover slopes, along with manzanita, gray pine, canyon live oak, and blue oak. Cooler portions of the park have higher proportions of pines and oaks, together with California buckeye, hollyleaf cherry, and coffeeberry. Willows and elderberries are found along the intermittent streams. Fire has been a dominant influence on the region's flora, both from natural causes and from intentional intervention by people. When the region was inhabited by Native Americans, they used fire as a tool to encourage the growth of preferred food sources, and to herd small game during hunting.  Since the disappearance of native peoples, the hills have become brushier.
Pinnacles National Park