Not exactly close by, but on the other side of Winchester there is a campground called the Cove that has a few trails. Half of them are acceptable for something like a stock wrangler with skid plates. The rest are for ATV/Motocross and rock crawlers. Not exactly sure of the mileage on them, but you can get lost for a few hours back there on them.
http://www.covecampground.com/