T. Denny Sanford, Bank Founder and Major Philanthropist, Dies at 90

July 18, 2026 - 21:47

T. Denny Sanford, the founder and chairman of First PREMIER Bank and PREMIER Bankcard, passed away at the age of 90. Sanford was widely recognized as the most significant philanthropist in South Dakota history, having donated hundreds of millions of dollars to healthcare, education, and children's causes.

Sanford built his fortune in the banking and credit card industry, turning First PREMIER Bank into one of the largest privately held banks in the United States. His business success allowed him to pursue extensive charitable giving, particularly in his adopted home state. He was the driving force behind the transformation of Sioux Valley Hospital into Sanford Health, a major regional healthcare system that now bears his name.

His donations also supported the Sanford Underground Research Facility in Lead, South Dakota, a former gold mine converted into a leading physics laboratory. He funded scholarships, youth programs, and medical research initiatives across the state. Despite his wealth, Sanford was known for a relatively low-profile personal life and a focus on practical results rather than public recognition.

Sanford's death marks the end of an era for South Dakota philanthropy and banking. His legacy will continue through the institutions and programs he helped build, which have had a lasting impact on the region's economy, healthcare, and education systems. No cause of death has been released publicly.