- Dr. Mark S. Harris Trinity Mills Chiropractic Centre DON T TURN YOUR BACK ON PAIN END IT! Past and present patients of North Dallas Chiropractor, Dr. Mark S. Harris, know that their livelihoods depend on their good health. Dr. Mark Harris credentials: 15 Years Experience Palmer College of Chiropractic Graduate Member American Chiropractic Association Member Texas Chiropractic Association Member ...www.webfeats.com/DrHarris