When I was a teenager, I used to go to a great spot about halfway to Lincoln. It usually took me about a 1/2 hour to get there from Fair Oaks. The problem is I heard they've developed some of that area.
Take I-80 East
Take the Highway towards Lincoln (I think it's Highway 63 or something like that).
Drive quite a ways on that highway and you'll come to an area of flat dirt land with a fence that runs along the highway (on your right).
There are several breaks in the fence.
Take one of these breaks and follow the dirt road until you find a place you like. I used to follow it all the way to the end. You drive down a hill and shoot against the same hill. Great spot for shooting.
4x4 is a must if it's muddy though. I got stuck all the time out there.