Gary Jon Duncan, 90, passed away on September 1, 2026, in McKinney, Texas. He was born on July 28, 1936, to parents Louis E. Duncan and Eva (Pierce) Duncan in Greenville, Texas.
Gary graduated from Commerce High School in 1954. He then went to college at East Texas State (A&M Commerce) and graduated in 1967 with a Bachelor of Science and Master of Education. He became a history and government teacher and coach at Safford High School in Arizona for 15 years. He retired from Olmsted-Kirk Paper Company in 2007.
Gary married JoAnne Reagan on July 14, 1979, in Dallas, Texas. They celebrated 42 years of marriage.
Gary honorably served in the U.S. Air Force Reserve.
Gary was a lifetime member of the National and Arizona Educational Associations. He was a CASA volunteer, a part of the Democratic Party Precinct 10, Fannin County Chair, and Trenton City Council member from 1997 to present. Gary was a member of the Crossroads Presbyterian Church in Desert, Texas.
Gary will be remembered by his daughter, Cheri (Duncan) Boerner; grandchildren, Douglas Gammill and Halee (Boerner) Stroud and husband, Trevor; great grandchildren, Deegan and Caydan Gammill; brother, Danny Duncan and wife, Janet (Chapin) Duncan; sister in law, Doris (Boyd) Duncan; and nieces and nephews, Sue (Duncan) Stogie, Doug Duncan and wife, Wendy, Guy Duncan and wife Natalie (Foster) Duncan, Donna (Duncan) Simon and husband Butch, Jennifer (Duncan) Pierce and husband Jeffrey; great nieces and nephews, Lindsey Gumz, Michelle Duncan, Melinda Duncan, Lisa (Duncan) Dahr and husband, Danny, Luke Duncan, Hoyt Duncan, Dean Duncan, Blair Duncan, Sarah Shortt and husband, Patrick Nolan, Daniel Simon, Abbie (Duncan) Lowe, Katie Duncan, Jack Pierce, and Jenna Pierce; great great nieces and nephews, Jeffrey Stevenson, Jayden Hilliard, Jasmine Hilliard, Journey Hilliard, Joseph Hudson, Andrew Hudson, Abigail Dahr, Hannah Dahr, Isabella Dahr, Jack Nolan, Max Nolan, and Tomas Nolan.
He was preceded in death by his wife, JoAnne Duncan; son, Jon Michael Duncan; parents, Louis and Eva Duncan; brothers, Louis Duncan and Gordon Duncan; sister, Willie Louise Duncan; sister-in-law, Ava "Abie" (Brecheen) Duncan; nephews, David Duncan (Louis’s son) and David Duncan (Danny’s son); and first wife and mother of Gary’s children, Sue (Weldon) Whiteside.
A funeral service will be held at 2 PM, Thursday, September 10, 2026, at Turrentine Jackson Morrow Funeral Home, 201 West Maple Street, Whitewright, Texas 75491. The family will greet guests at a visitation an hour prior. Following the services, the burial will be at Indian Creek Cemetery.