Penngrove, California 94951, USA is a small, unincorporated community in Sonoma County, between Petaluma and Cotati at the intersection of Old Redwood Highway and Petaluma Hill Road, nestled in the foothills of Sonoma Mountain. Located in the remnants of a historic grove called Penn's Grove, it was previously a North Bay freight rail station on the Northwestern Pacific Railroad as well as a center for egg and chicken farming, much like its close neighbor Petaluma. Every year on the Sunday closest to the 4th Penngrove celebrates the 4th of July with a parade sponsored by the Penngrove Social Fireman. On Saturday at the Penngrove Fire Station located at the corner of Main Street and Old Redwood Highway, the Rancho Adobe Firefighters Association sponsor a breakfast.