What kind of riding do you do Rudy? There is a cool track up by Vacaville, http://argyllmx.com/. Fun place to ride of MX is your thing. Also for trail riding, there is Stonyford, Im not sure how to get there, but it is off the 5 by Williams. A few other tracks within about an hour from you is SandhillRacing.com and clubmoto.com. There is also Riverfront and E Street both in Marysville Ca.
Hope this helps you out,
Lata,
Rick