Sorry I missed this. The best place nearby is in Bridgeport OHV, just NW of Ft. Worth. I've been there about 6 times .
A great way to get connected with other Toyota off-roaders is our Dallas-based club called Toyota Trail Riders. We meet on the 2nd Thur night of the month at Papa's BBQ on NW Highway near 35. The club does at least 1 off-roading event a month, plus an annual Toyota Jamboree out in Gilmer, TX at Barnwell OHV.
I have photos here of some of the events:
Toyota Off-roading - a set on Flickr
There's also a new park south of Ft. Worth near Tolar. Turns out the land owner goes to my church. He and I have chatted about the trails. I need to get down there and check it out. Here's their website:
http://www.rocktrails.com/