Forty miles of trails are available to horseback riders and hikers. In addition to developed campgrounds, boat-in campsites and many picnic areas, Lake Sonoma hosts the Don Clausen Fish Hatchery, which is the most modern fish hatchery in the State of California. The parks in and near Santa Rosa, the County seat and largest city of Sonoma County include historic Luther Burbank Gardens , Howarth Park, Spring Lake Park, and Annadel State Park . The Valley of the Moon. Highway 12 runs east from Santa Rosa to the town of Sonoma through the Valley of the Moon, bounded by the Mayacamas mountains on the north and Sonoma Mountain to the South.
Extensive vineyards stretch along the highway on both sides.
The parks include Hood Mountain Regional Park , Sugarloaf Ridge State Park, which includes the Valley of the Moon Observatory , and Jack London State Historic Park. It's Springtime in the Valley of the Moon Historic Sonoma and Petaluma Adobe. Sonoma State Historic Park consists several restored historic buildings which date back to the earliest days of the Mexican era and the beginnings of California as part of the United States. Rancho Petaluma was by all accounts the largest and richest privately owned Mexican estates north of San Francisco Bay and one of the most important in Alta California. Exact boundaries of the rancho were of great debate especially after U.S. take-over of California in 1846.