Donald Eugene Tjarksen, known to family and friends as Don, passed away on August 12, 2026, in Lake Forest, Illinois, at the age of 89.
Don was born on August 2, 1937, in Peoria, Illinois, and lived a life marked by devotion, integrity, hard work, and a deep love for those around him. He was a Christian whose faith and values guided the way he lived, the way he worked, and the way he cared for his family and friends. Don was an accomplished middle distance runner at Peoria Central High School earning many local and state honors. Don attended the University of Illinois on a track scholarship, setting records in an accomplished running career. He earned a Bachelor of Science in Mechanical Engineering and carried the discipline and curiosity of his education into every chapter of his life. Don was also proud and active life long member of Sigma Chi fraternity and lived by that creed daily honoring the white cross and blue shield in his thoughts, words and actions.
Don built a meaningful career as an entrepreneur, business owner, and real estate investor. He approached his work with intelligence, determination, and a steady hand, earning the respect of those who knew him professionally and personally. He had a natural ability to see opportunity, understand the details, and make thoughtful decisions, and he applied those gifts with care and confidence throughout his life. He also enjoyed learning and applying the ins and outs of the stock market, a pursuit that reflected both his sharp mind and his lifelong interest in how things worked.
Above all else, Don was a true family man. He took great joy in celebrating anything and everything his children and grandchildren accomplished, and his pride in them was evident to all who knew him. He was a devoted husband, father, grandfather, and great-grandfather whose love for his family was constant and unwavering. He is survived by his beloved wife and best friend of 67 years, Jane Tjarksen; his daughters, Susan Tjarksen and her husband, Walter Radloff, and Cynthia Tjarksen Nedeau and her husband, John Nedeau Jr.; his son, Michael Tjarksen, and his wife, Constance Tjarksen; his grandchildren: Sarah Nedeau, John Nedeau III, Hannah Nedeau Flanagan and her husband, Brian Flanagan, James Tjarksen and his wife, Tess Tjarksen, Nicholas Tjarksen and his wife, Zoe Tjarksen, Caroline Tjarksen Hower and her husband, Jake Hower, Benjamin Tjarksen, and Gabriella Tjarksen Roussos; and his great-grandchildren, Mac Tjarksen and Gavin Tjarksen. He is also survived by step-grandson Sebastian Radloff and wife Catherine Radloff and step-granddaughter Anastasia Radloff Zipf and her husband Kevin Zipf and two step-great grandchildren Lucas Radloff and Henry Zipf. He is also survived by his loving sister Nancy Tjarksen Myers. His brothers Bernard Tjarksen and Richard Tjarksen pre-deceased him.
Don was also a loyal and lifelong friend. He valued relationships deeply and was the kind of man people could count on for support and encouragement. His warmth, steadiness, and sincerity left a lasting impression on those fortunate enough to know him. He made time for the people and activities he loved, and he lived with a sense of gratitude and purpose that inspired others.
In addition to his family and professional accomplishments, Don enjoyed an active and full life. He was an avid runner and golfer, and he appreciated the discipline and enjoyment that came with both pursuits. He was also a world traveler, and with Jane by his side, he embraced the opportunity to see new places by plane, helicopter, cruise boat and dogsled. Whether at home, on the course, on the road, or with family nearby, he brought enthusiasm and a healthy appetite to each family and friends gathering. Don was also an active philanthropist supporting many causes that he and Jane believed in, particularly those in the arts and higher education.
Don’s life reflected the wisdom of a saying he used often: “it’s important to finish strong”. By that measure, Don succeeded beautifully. He touched many lives with his love, his example, and his steadfast character, and his memory will be cherished always by those who knew and loved him.
A Memorial Service will be held at 11:00 am on Friday, August 21, 2026 at St James Lutheran Church, 1380 N. Waukegan Road, Lake Forest, Illinois.
Don was laid to rest at Oakwood Memorial Park in the Garden of Inspiration.