Texas riders don't need a special off-roading license. However, you must have asafety certificate from a certified safety training provider. The only exceptions to this rule are for people who are taking a safety training course—and are under the direct supervision of a certified ATV safety instructor—or for those who are under the direct supervision of an adult who has a safety certificate. You must carry the certificate with you any time you're riding, and if a law enforcement officer asks to see it, you have to offer it up.
Check out these Fredericksburg, TX ATV/OHV resources: