Doug Hawthorne, the longtime chief executive officer of Arlington-based Texas Health Resources, announced his intention to step down as leader of the North Texas hospital company by the end of the year. Hawthorne, 66, has been CEO since Texas Health Resources was created in 1997 through the merger of Presbyterian Healthcare Resources in Dallas, Harris Methodist Health System in Fort Worth and Arlington Memorial Hospital. At the time, Hawthorne was president and CEO of Presbyterian Healthcare. "For 43 years, my family and I have been blessed to serve Texas Health Resources," Hawthorne said in a letter to the board and other leaders of Texas Health. "This has been an amazing journey and one for which I am extremely grateful."