Shreveport/Bossier City, La. has Harrah's, Hollywood, Horseshoe, Isle of Capri, and Boomtown casinos. 3 hour drive.
Winstar Casino, a tribal casino in OK, just north of Gainsville Tx, is just over one hour drive from Ft Worth, and another tribal casino in Durant OK, just north of Sherman/Dennison, Tx is an hour drive from Dallas. the tribal casinos only has class II slots and bingo.