"Primitive" camping (camping in undeveloped areas) is authorized only within areas operated by the US Forest Service in either the Angelina or Sabine National Forests. Camping is prohibited in undeveloped areas managed by the US Army Corps of Engineers.
For additional information on camping in undeveloped areas, contact the US Forest Service at:
Angelina National Forest: http://www.fs.fed.us/r8/texas/recreation/angelina/angelina_gen_info.shtml
Sabine National Forest: http://www.fs.fed.us/r8/texas/recreation/sabine/sabine_gen_info.shtml