Vallejo might work, but watch out for debris and the puddles, they're 3X deeper then you'll think they are. It's right by the homedepot
, you can see if from the free way.
Also in the Northbay, in Novato, there's a place called Hannah ranch, technically not a legal wheeling spot but the cops don't usually bug anyone, it's right at the conjunction of Highway 37 and 101. Good spot with roughly 50 acres to wheel.
Hollister, Frank Raines, Cow Mountain, and Pillsbury would all be good choices. My recommendation if you want to make a day out of wheeling is go to Cow Mountain and stay on some of the lighter trails, bring some guns to shoot and a lunch, and enjoy the scenic drive through clearlake to get back home.
But if you just want to get the truck dirty and confuse some mexicans then go fling some dirt at Vallejo.