[3] The Sonoma Mountains range is approximately fourteen miles (23 km) long.

The highest point of this range is Sonoma Mountain, elevation 2,287 ft (697 m).

A number of threatened and endangered species are found in the Sonoma Mountains including the fragrant fritillary (Fritillaria liliacea).

From the northwestern slopes, Copeland Creek and Hinebaugh Creek flow to the Laguna de Santa Rosa, eventually entering the Pacific Ocean just south of Jenner, California.

These eventually enter San Pablo Bay south of Sonoma, California.