Rural hospitals across the country are closing, but a newly formed organization in Southern Arizona is looking to buck that trend. Tucson Medical Center is expected to announce Monday that it is the hub and founding member of the fledgling not-for-profit Southern Arizona Hospital Alliance, which includes four rural hospitals. Combined, those rural hospitals serve more than 70,000 people — Benson Hospital in Benson; Mount Graham Regional Medical Center in Safford; Northern Cochise Community Hospital in Willcox and Copper Queen Community Hospital in Bisbee. Like TMC, rural hospitals in the new partnership want to remain independent, nonprofit and locally governed, a desire that is becoming increasingly difficult as health-care costs rise and larger health systems acquire smaller hospitals, clinics and physician practices.