Rohnert Park is a city in Sonoma County, California, United States, located approximately 50 miles (80 km) north of San Francisco. The population at the 2020 United States Census was 44,390. It is an early planned city and is the sister city of Hashimoto in Japan. Sonoma State University, part of the California State University system, is located nearby.

Cotati is an incorporated city in Sonoma County, California, United States, located approximately 45 mi (70 km) north of San Francisco in the 101 corridor between Rohnert Park and Petaluma. Cotati's population as of the 2020 Census was 7,584, making it the smallest incorporated community in Sonoma County.