In early 1980, a group of professionals and local citizens collaborated to form the Tri-County Health Team in order to address the mental health needs in Creek, Okmulgee & Okfuskee County. The team was awarded funds to begin their agenda of providing and promoting mental health services to those without health insurance or money to pay for mental health services. Then President of the Okmulgee County Mental Health Association and Okmulgee County Representative, Irene Horn, began the task to form a non-profit corporation that would oversee the mental health program implementation. On June 25, 1980, the newly founded corporation would be called CREOKS Mental Health Services, Inc., which is an acronym formed from the first three counties, Creek, Okmulgee and Okfuskee. Less than eight months later, CREOKS opened its first location in Okmulgee. Clinics in Sapulpa and Okemah opened shortly thereafter. From the opening of the CREOKS Tulsa clinic in 2004 through today, CREOKS has grown to include clinics in Claremore, Tahlequah, Stilwell, Wagoner, Bartlesville, McAlester, Pawnee, Sallisaw, Shawnee, Oklahoma City, Stillwater, Miami, Atoka, Poteau, Muskogee, Broken Arrow, and Lawton. Currently CREOKS has 22 clinics, serving individuals and families in approximately 45 counties and over 300 communities in Eastern Oklahoma.

The growth is not limited to outpatient clinics. In 2014, CREOKS opened Spring Creek Recovery Center in Sapulpa, which is a crisis stabilization facility with 8 psychiatric urgent care recliners and 16 private-room beds. In 2017, CREOKS opened its first retail pharmacy, TruWellness RX and medical clinic, TruHealth Integrated Care in Sapulpa.