Dr. Jack O. Clark is a board-certified Internal Medicine physician and the Hospitalist Director at Madison Memorial Hospital. With over two decades of experience since beginning his practice in 1999, Dr. Clark is committed to delivering expert care to adult patients in both the medical/surgical and intensive care units.

He completed his medical education at the University of Utah School of Medicine and went on to train in Internal Medicine at Penn State/Geisinger. Dr. Clark is especially passionate about the diagnostic process, combining patient interviews, laboratory testing, diagnostic imaging (X-ray, CT, MRI, Nuclear Medicine), and close collaboration with fellow providers to uncover the root causes of complex conditions.

His clinical focus includes the care of hospitalized adults, with a strong interest in intensive care medicine.
“I chose Internal Medicine because I love speaking with people about their health concerns. I enjoy the interaction, learning from their experiences, and helping guide decisions around treatments. It’s incredible how far diagnostic tools and therapies have come over the course of my career.”

Originally from Wyoming, Dr. Clark has a deep love for Yellowstone and Grand Teton National Parks. He is an avid cyclist and triathlete, having completed multiple Logan-to-Jackson bike races and three Ironman-distance triathlons. Outside of medicine, he finds joy in community and church service, traveling—especially to visit his 11 children and nearly 30 grandchildren—and enjoying the outdoors.