Since 1968 our goal has been straightforward: help clients get their life back on track and achieve a life of sobriety, free from drug use and symptoms of mental illness. A life that is productive, socially responsible, and healthy. Gateway Foundation is the largest nonprofit treatment provider with treatment programs in California, Delaware, Florida, Illinois, Michigan, Missouri, New Jersey, Texas and Wyoming that specialize in substance use disorders for men, women, adolescents, and clients diagnosed with co-occurring mental health disorders. Gateways professional clinicians support over 9,000 people a day to successfully complete treatment by developing a personalized plan to treat the underlying causes of substance use disorder —not just their addiction to drugs or alcohol. Located in a secluded setting and easily accessible via Interstates 64 and 225, Gateway Foundation’s Caseyville location serves patients in St. Louis, southern Illinois and throughout Illinois.