Kisatchie National Forest
http://www.fs.fed.us/r8/kisatchie/ohv/index.html

Sam Houston National Forest
http://www.fs.fed.us/r8/texas/recreation/orv_info_ang_dc_sab.shtml
also see the Trail Riders of Houston forum for maps.

If it gives you a thrill, you can ride down the beach from Sea Rim State Park (closed by hurricane Ike) to High Island, or you can ride on the beach in Louisiana from Johnson Bayou to Cameron. I'm not sure if you are supposed to be street legal to ride on the beach, I don't think so. There are speed limits on the beach which are occasionally enforced. Last time I went a couple of months ago, there was a long stretch between Sea Rim and High Island that had very nasty deep mud. I know one local rider got his bike stuck in it and had to dig out.

Angelina National Forest may be open again someday, but no prediction when at this point.

Bottom line - no trails that are open to the public that are close to Bmt, that I know of anyway. That's why I have a dual sport bike instead of a pure trail bike.