Dr. Thomas Callahan came back to St. George in 1980 after medical school at the University of Utah and a three-year family medicine residency at St. Joseph's Hospital in Phoenix. He has been seeing patients in the same city ever since — which means he has watched the population of Washington County grow from roughly 25,000 people to more than 200,000 without leaving. In that time the Callahan family has become the practice itself.
His son Dr. Douglas Callahan, DO joined in 2003 after Des Moines University and his own St. Joseph's residency. His younger son Dr. Thomas "Colby" Callahan, DO followed in 2013 after Southern Utah University, Edward Via College of Osteopathic Medicine, and a third St. Joseph's residency — a pipeline that is either remarkable family continuity or a very long-running recruitment strategy, depending on how you read it. Two family nurse practitioners, Amanda Turner and Alana Bradbury, round out the clinical staff.
The clinic is at 1240 E 100 S — the same east-side medical corridor that houses several of the city's longest-tenured private practices — and offers family medicine for all ages, preventive care, and chronic disease management.
**Verification notes** Website live; 30+ year history confirmed per site and Healthgrades provider profiles; founding confirmed as 1980 via Dr. Thomas Callahan's provider history; family ownership confirmed via provider list; address consistent.