Trione-Annadel State Park in Santa Rosa covers about 5,000 acres of oak woodlands, grassy hills and wildflower meadows on the edge of Sonoma Valley. It is a favorite among trail runners and hikers, with miles of well-kept trails and rolling terrain. Lake Ilsanjo offers a scenic spot for quiet walks and wildlife watching, and spring wildflowers make the meadows especially colorful. The park's mix of habitats supports a wide variety of birds and other animals, and the trails are open to hikers, bikers and equestrians. Entry is $10 per vehicle. It is an easy escape for anyone visiting Santa Rosa or the wine country.