Round Valley Regional Preserve 
Marsh Creek Rd.
Clayton, CA 94517
888-327-2757
http://ebparks.org/parks/round_valley
Nature Preserve: Bike, Birding, Hike, Horse, Picnic, Walk
The 2,000 acre preserve is open for hiking, horseback riding and bicycling (with some restrictions). The climate at the preserve is arid and temperatures commonly exceed 100 degrees Fahrenheit in the summer months. Be prepared for the summer heat: use sunscreen, wear a hat and loose-fitting clothing, wear good hiking shoes, and bring plenty of water. Operated by the East Bay Regional Park District.