Penngrove, California

Penngrove is a census-designated place (CDP) in Sonoma County, California, United States, situated between the cities of Petaluma and Cotati, at the foot of Sonoma Mountain. It is part of the North Bay subregion of the San Francisco Bay Area. The population was 2,522 at the 2010 census.The site of a historic grove called Penn's Grove, it was formerly a freight station on the Northwestern Pacific Railroad and a center of egg and chicken farming.GeographyPenngrove's downtown consists of Main Street, a 0.3mi street linking Old Redwood Highway to Adobe Road. Penngrove School is located at the corner of Adobe Road, where Main Street becomes Petaluma Hill Road.Lichau Creek flows southward through the town, paralleling the railway. The creek feeds into the Petaluma River, which flows to San Pablo Bay.Due to the Sonoma Mountain's ancient volcanism, Penngrove is rich with obsidian and petrified wood. Its soil is unique, composed mainly of clay-like adobe, which has been used for centuries as building material. A prime example of adobe architecture is the Rancho Petaluma Adobe, a State Historic Park in nearby Petaluma.