Jim Ostertag

James Michael Ostertag
February 25, 1947 – July 13, 2025

James Michael Ostertag, affectionately known as "Big Jim," passed away on Sunday, July 13, 2025, in Mount Vernon, TX, at the age of 78. Born on February 25, 1947, in Oshkosh, WI. Jim lived a life marked by compassion, humor, and an unwavering love for family, baseball, and service to others.

A proud graduate of El Centro College in Dallas, Jim was part of the inaugural military medic program. He served honorably in the Navy as a medic and went on to a distinguished 35-year career as an orthopedic surgical nurse. Notably, he was a member of the medical team that performed the first heart transplant in Texas, a testament to his skill and dedication.

Jim’s passion for baseball was legendary. A savant of the sport, he coached Little League for many years and became a prominent umpire in the Dallas area, officiating high school and college games for over 20 years. His knowledge and love for the game left a lasting impact on the community.

Known for his big heart and silly sense of humor, Jim brought joy to those around him. He celebrated his “decade birthdays” (40, 50, 60, and 70) with childlike enthusiasm at Chuck E. Cheese, creating cherished memories with family and close friends.

Jim was preceded in death by his parents, Lawrence and Anna Jane Ostertag, his sister Julie Grow, and his beloved daughter, Amy Ostertag. He is survived by his devoted wife of 54 years, Jean Ostertag; his son, Greg Ostertag, and daughter-in-law, Shannon Ostertag; his grandchildren, Cody Ostertag (Paige), Bailey Ostertag, Shelby Ostertag, Charlee Ostertag, Trevor Ruelas, and Lily Ruelas; his great-grandson, Oliver Ostertag; and his sister, JoAnne Fellner (Bill).

A Celebration of Life will be announced soon. In lieu of flowers, the family kindly requests donations to the American Kidney Association, a cause close to Jim’s heart.

Jim’s legacy of love, laughter, and service will live on in the hearts of all who knew him.